diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst
index dd913eefbf312..33d3c988b9515 100644
--- a/Documentation/admin-guide/cgroup-v1/memory.rst
+++ b/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -64,6 +64,7 @@ Brief summary of control files.
 				     threads
  cgroup.procs			     show list of processes
  cgroup.event_control		     an interface for event_fd()
+				     This knob is not available on CONFIG_PREEMPT_RT systems.
  memory.usage_in_bytes		     show current usage for memory
 				     (See 5.5 for details)
  memory.memsw.usage_in_bytes	     show current usage for memory+Swap
@@ -75,6 +76,7 @@ Brief summary of control files.
  memory.max_usage_in_bytes	     show max memory usage recorded
  memory.memsw.max_usage_in_bytes     show max memory+Swap usage recorded
  memory.soft_limit_in_bytes	     set/show soft limit of memory usage
+				     This knob is not available on CONFIG_PREEMPT_RT systems.
  memory.stat			     show various statistics
  memory.use_hierarchy		     set/show hierarchical account enabled
                                      This knob is deprecated and shouldn't be
diff --git a/Documentation/dev-tools/kcov.rst b/Documentation/dev-tools/kcov.rst
index d2c4c27e1702d..d83c9ab494275 100644
--- a/Documentation/dev-tools/kcov.rst
+++ b/Documentation/dev-tools/kcov.rst
@@ -50,6 +50,7 @@ program using kcov:
     #include <sys/mman.h>
     #include <unistd.h>
     #include <fcntl.h>
+    #include <linux/types.h>
 
     #define KCOV_INIT_TRACE			_IOR('c', 1, unsigned long)
     #define KCOV_ENABLE			_IO('c', 100)
@@ -177,6 +178,8 @@ Comparison operands collection is similar to coverage collection:
 	/* Read number of comparisons collected. */
 	n = __atomic_load_n(&cover[0], __ATOMIC_RELAXED);
 	for (i = 0; i < n; i++) {
+		uint64_t ip;
+
 		type = cover[i * KCOV_WORDS_PER_CMP + 1];
 		/* arg1 and arg2 - operands of the comparison. */
 		arg1 = cover[i * KCOV_WORDS_PER_CMP + 2];
@@ -251,6 +254,8 @@ selectively from different subsystems.
 
 .. code-block:: c
 
+    /* Same includes and defines as above. */
+
     struct kcov_remote_arg {
 	__u32		trace_mode;
 	__u32		area_size;
diff --git a/arch/alpha/include/asm/spinlock_types.h b/arch/alpha/include/asm/spinlock_types.h
index 1d5716bc060be..2526fd3be5fd7 100644
--- a/arch/alpha/include/asm/spinlock_types.h
+++ b/arch/alpha/include/asm/spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef _ALPHA_SPINLOCK_TYPES_H
 #define _ALPHA_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 74357ce8967b4..987f4ae74000d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -33,6 +33,7 @@ config ARM
 	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
+	select ARCH_SUPPORTS_RT if HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select ARCH_USE_MEMTEST
@@ -69,7 +70,7 @@ config ARM
 	select HARDIRQS_SW_RESEND
 	select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
 	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
-	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
+	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU && !PREEMPT_RT
 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
 	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
 	select HAVE_ARCH_MMAP_RND_BITS if MMU
@@ -110,6 +111,7 @@ config ARM
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RSEQ
@@ -125,6 +127,7 @@ config ARM
 	select OLD_SIGSUSPEND3
 	select PCI_SYSCALL if PCI
 	select PERF_USE_VMALLOC
+	select HAVE_POSIX_CPU_TIMERS_TASK_WORK if !KVM
 	select RTC_LIB
 	select SYS_SUPPORTS_APM_EMULATION
 	select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
diff --git a/arch/arm/include/asm/spinlock_types.h b/arch/arm/include/asm/spinlock_types.h
index 5976958647fe1..0c14b36ef1013 100644
--- a/arch/arm/include/asm/spinlock_types.h
+++ b/arch/arm/include/asm/spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index b682189a2b5df..e5e2ceb595440 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -52,6 +52,7 @@ struct cpu_context_save {
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
+	int			preempt_lazy_count; /* 0 => preemptable, <0 => bug */
 	struct task_struct	*task;		/* main task structure */
 	__u32			cpu;		/* cpu */
 	__u32			cpu_domain;	/* cpu domain */
@@ -130,6 +131,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp *,
 #define TIF_NOTIFY_RESUME	2	/* callback before returning to user */
 #define TIF_UPROBE		3	/* breakpointed or singlestepping */
 #define TIF_NOTIFY_SIGNAL	4	/* signal notifications exist */
+#define TIF_NEED_RESCHED_LAZY	9
 
 #define TIF_USING_IWMMXT	17
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
@@ -149,6 +151,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp *,
 #define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
 #define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_USING_IWMMXT	(1 << TIF_USING_IWMMXT)
 
 /* Checks for any syscall work in entry-common.S */
@@ -158,7 +161,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp *,
 /*
  * Change these and you break ASM code in entry-common.S
  */
-#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
+#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY | \
+				 _TIF_SIGPENDING | \
 				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
 				 _TIF_NOTIFY_SIGNAL)
 
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index a646a3f6440f8..beb09d74684fd 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -43,6 +43,7 @@ int main(void)
   BLANK();
   DEFINE(TI_FLAGS,		offsetof(struct thread_info, flags));
   DEFINE(TI_PREEMPT,		offsetof(struct thread_info, preempt_count));
+  DEFINE(TI_PREEMPT_LAZY,	offsetof(struct thread_info, preempt_lazy_count));
   DEFINE(TI_TASK,		offsetof(struct thread_info, task));
   DEFINE(TI_CPU,		offsetof(struct thread_info, cpu));
   DEFINE(TI_CPU_DOMAIN,		offsetof(struct thread_info, cpu_domain));
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 68261a83b7ad8..fa7d110ce5555 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -206,11 +206,18 @@ __irq_svc:
 
 #ifdef CONFIG_PREEMPTION
 	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count
-	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
 	teq	r8, #0				@ if preempt count != 0
+	bne	1f				@ return from exeption
+	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
+	tst	r0, #_TIF_NEED_RESCHED		@ if NEED_RESCHED is set
+	blne	svc_preempt			@ preempt!
+
+	ldr	r8, [tsk, #TI_PREEMPT_LAZY]	@ get preempt lazy count
+	teq	r8, #0				@ if preempt lazy count != 0
 	movne	r0, #0				@ force flags to 0
-	tst	r0, #_TIF_NEED_RESCHED
+	tst	r0, #_TIF_NEED_RESCHED_LAZY
 	blne	svc_preempt
+1:
 #endif
 
 	svc_exit r5, irq = 1			@ return from exception
@@ -225,8 +232,14 @@ svc_preempt:
 1:	bl	preempt_schedule_irq		@ irq en/disable is done inside
 	ldr	r0, [tsk, #TI_FLAGS]		@ get new tasks TI_FLAGS
 	tst	r0, #_TIF_NEED_RESCHED
+	bne	1b
+	tst	r0, #_TIF_NEED_RESCHED_LAZY
 	reteq	r8				@ go again
-	b	1b
+	ldr	r0, [tsk, #TI_PREEMPT_LAZY]	@ get preempt lazy count
+	teq	r0, #0				@ if preempt lazy count != 0
+	beq	1b
+	ret	r8				@ go again
+
 #endif
 
 __und_fault:
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 539897ac28284..4655f04ccdcdf 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -607,7 +607,8 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 	 */
 	trace_hardirqs_off();
 	do {
-		if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+		if (likely(thread_flags & (_TIF_NEED_RESCHED |
+					   _TIF_NEED_RESCHED_LAZY))) {
 			schedule();
 		} else {
 			if (unlikely(!user_mode(regs)))
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index bf1577216ffab..89d6a8a0099a1 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -407,6 +407,9 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
 	if (addr < TASK_SIZE)
 		return do_page_fault(addr, fsr, regs);
 
+	if (interrupts_enabled(regs))
+		local_irq_enable();
+
 	if (user_mode(regs))
 		goto bad_area;
 
@@ -477,6 +480,9 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
 static int
 do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
+	if (interrupts_enabled(regs))
+		local_irq_enable();
+
 	do_bad_area(addr, fsr, regs);
 	return 0;
 }
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 06ef732c0472c..1451ee83189a2 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -88,6 +88,7 @@ config ARM64
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
 	select ARCH_SUPPORTS_NUMA_BALANCING
+	select ARCH_SUPPORTS_RT if HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
 	select ARCH_WANT_DEFAULT_BPF_JIT
 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
@@ -191,6 +192,7 @@ config ARM64
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_REGS_AND_STACK_ACCESS_API
+	select HAVE_PREEMPT_LAZY
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select MMU_GATHER_RCU_TABLE_FREE
@@ -212,6 +214,7 @@ config ARM64
 	select PCI_DOMAINS_GENERIC if PCI
 	select PCI_ECAM if (ACPI && PCI)
 	select PCI_SYSCALL if PCI
+	select HAVE_POSIX_CPU_TIMERS_TASK_WORK if !KVM
 	select POWER_RESET
 	select POWER_SUPPLY
 	select SPARSE_IRQ
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index a1902dcf7a7e3..116887e0a8373 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1009,7 +1009,7 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
  */
 static inline bool arch_faults_on_old_pte(void)
 {
-	WARN_ON(preemptible());
+	WARN_ON(is_migratable());
 
 	return !cpu_has_hw_af();
 }
diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index e83f0982b99c1..2545c17281e1c 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -70,13 +70,36 @@ static inline bool __preempt_count_dec_and_test(void)
 	 * interrupt occurring between the non-atomic READ_ONCE/WRITE_ONCE
 	 * pair.
 	 */
-	return !pc || !READ_ONCE(ti->preempt_count);
+	if (!pc || !READ_ONCE(ti->preempt_count))
+		return true;
+#ifdef CONFIG_PREEMPT_LAZY
+	if ((pc & ~PREEMPT_NEED_RESCHED))
+		return false;
+	if (current_thread_info()->preempt_lazy_count)
+		return false;
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+#else
+	return false;
+#endif
 }
 
 static inline bool should_resched(int preempt_offset)
 {
+#ifdef CONFIG_PREEMPT_LAZY
+	u64 pc = READ_ONCE(current_thread_info()->preempt_count);
+	if (pc == preempt_offset)
+		return true;
+
+	if ((pc & ~PREEMPT_NEED_RESCHED) != preempt_offset)
+		return false;
+
+	if (current_thread_info()->preempt_lazy_count)
+		return false;
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+#else
 	u64 pc = READ_ONCE(current_thread_info()->preempt_count);
 	return pc == preempt_offset;
+#endif
 }
 
 #ifdef CONFIG_PREEMPTION
diff --git a/arch/arm64/include/asm/signal.h b/arch/arm64/include/asm/signal.h
index ef449f5f4ba80..5e535c3e49260 100644
--- a/arch/arm64/include/asm/signal.h
+++ b/arch/arm64/include/asm/signal.h
@@ -22,4 +22,8 @@ static inline void __user *arch_untagged_si_addr(void __user *addr,
 }
 #define arch_untagged_si_addr arch_untagged_si_addr
 
+#if defined(CONFIG_PREEMPT_RT)
+#define ARCH_RT_DELAYS_SIGNAL_SEND
+#endif
+
 #endif
diff --git a/arch/arm64/include/asm/spinlock_types.h b/arch/arm64/include/asm/spinlock_types.h
index 18782f0c47212..11ab1c0776977 100644
--- a/arch/arm64/include/asm/spinlock_types.h
+++ b/arch/arm64/include/asm/spinlock_types.h
@@ -5,7 +5,7 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#if !defined(__LINUX_SPINLOCK_TYPES_H) && !defined(__ASM_SPINLOCK_H)
+#if !defined(__LINUX_SPINLOCK_TYPES_RAW_H) && !defined(__ASM_SPINLOCK_H)
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 6623c99f09841..c55ccec33a5a2 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -26,6 +26,7 @@ struct thread_info {
 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
 	u64			ttbr0;		/* saved TTBR0_EL1 */
 #endif
+	int			preempt_lazy_count;	/* 0 => preemptable, <0 => bug */
 	union {
 		u64		preempt_count;	/* 0 => preemptible, <0 => bug */
 		struct {
@@ -67,6 +68,7 @@ int arch_dup_task_struct(struct task_struct *dst,
 #define TIF_UPROBE		4	/* uprobe breakpoint or singlestep */
 #define TIF_MTE_ASYNC_FAULT	5	/* MTE Asynchronous Tag Check Fault */
 #define TIF_NOTIFY_SIGNAL	6	/* signal notifications exist */
+#define TIF_NEED_RESCHED_LAZY	7
 #define TIF_SYSCALL_TRACE	8	/* syscall trace active */
 #define TIF_SYSCALL_AUDIT	9	/* syscall auditing */
 #define TIF_SYSCALL_TRACEPOINT	10	/* syscall tracepoint for ftrace */
@@ -97,8 +99,10 @@ int arch_dup_task_struct(struct task_struct *dst,
 #define _TIF_SVE		(1 << TIF_SVE)
 #define _TIF_MTE_ASYNC_FAULT	(1 << TIF_MTE_ASYNC_FAULT)
 #define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 
-#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
+#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY | \
+				 _TIF_SIGPENDING | \
 				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
 				 _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \
 				 _TIF_NOTIFY_SIGNAL)
@@ -107,6 +111,8 @@ int arch_dup_task_struct(struct task_struct *dst,
 				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
 				 _TIF_SYSCALL_EMU)
 
+#define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
+
 #ifdef CONFIG_SHADOW_CALL_STACK
 #define INIT_SCS							\
 	.scs_base	= init_shadow_call_stack,			\
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 551427ae8cc52..96a4f6c9eb787 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -31,6 +31,7 @@ int main(void)
   BLANK();
   DEFINE(TSK_TI_FLAGS,		offsetof(struct task_struct, thread_info.flags));
   DEFINE(TSK_TI_PREEMPT,	offsetof(struct task_struct, thread_info.preempt_count));
+  DEFINE(TSK_TI_PREEMPT_LAZY,	offsetof(struct task_struct, thread_info.preempt_lazy_count));
 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
   DEFINE(TSK_TI_TTBR0,		offsetof(struct task_struct, thread_info.ttbr0));
 #endif
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index db1ed940a6dc3..b9e60340e879a 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -181,10 +181,19 @@ static void __get_cpu_fpsimd_context(void)
  *
  * The double-underscore version must only be called if you know the task
  * can't be preempted.
+ *
+ * On RT kernels local_bh_disable() is not sufficient because it only
+ * serializes soft interrupt related sections via a local lock, but stays
+ * preemptible. Disabling preemption is the right choice here as bottom
+ * half processing is always in thread context on RT kernels so it
+ * implicitly prevents bottom half processing as well.
  */
 static void get_cpu_fpsimd_context(void)
 {
-	local_bh_disable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_bh_disable();
+	else
+		preempt_disable();
 	__get_cpu_fpsimd_context();
 }
 
@@ -205,7 +214,10 @@ static void __put_cpu_fpsimd_context(void)
 static void put_cpu_fpsimd_context(void)
 {
 	__put_cpu_fpsimd_context();
-	local_bh_enable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_bh_enable();
+	else
+		preempt_enable();
 }
 
 static bool have_cpu_fpsimd_context(void)
@@ -1078,6 +1090,7 @@ void fpsimd_thread_switch(struct task_struct *next)
 void fpsimd_flush_thread(void)
 {
 	int vl, supported_vl;
+	void *sve_state = NULL;
 
 	if (!system_supports_fpsimd())
 		return;
@@ -1090,7 +1103,10 @@ void fpsimd_flush_thread(void)
 
 	if (system_supports_sve()) {
 		clear_thread_flag(TIF_SVE);
-		sve_free(current);
+
+		/* Defer kfree() while in atomic context */
+		sve_state = current->thread.sve_state;
+		current->thread.sve_state = NULL;
 
 		/*
 		 * Reset the task vector length as required.
@@ -1126,6 +1142,7 @@ void fpsimd_flush_thread(void)
 	current->thread.fp_type = FP_STATE_FPSIMD;
 
 	put_cpu_fpsimd_context();
+	kfree(sve_state);
 }
 
 /*
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 768de05b616b4..70c4496c54b7a 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -925,7 +925,7 @@ static void do_signal(struct pt_regs *regs)
 void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags)
 {
 	do {
-		if (thread_flags & _TIF_NEED_RESCHED) {
+		if (thread_flags & _TIF_NEED_RESCHED_MASK) {
 			/* Unmask Debug and SError for the next task */
 			local_daif_restore(DAIF_PROCCTX_NOIRQ);
 
@@ -933,6 +933,14 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags)
 		} else {
 			local_daif_restore(DAIF_PROCCTX);
 
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+			if (unlikely(current->forced_info.si_signo)) {
+				struct task_struct *t = current;
+				force_sig_info(&t->forced_info);
+				t->forced_info.si_signo = 0;
+			}
+#endif
+
 			if (thread_flags & _TIF_UPROBE)
 				uprobe_notify_resume(regs);
 
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 5ca8782edb960..66f546fda0b1e 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -830,7 +830,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		 * involves poking the GIC, which must be done in a
 		 * non-preemptible context.
 		 */
-		preempt_disable();
+		migrate_disable();
 
 		kvm_pmu_flush_hwstate(vcpu);
 
@@ -854,7 +854,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 				kvm_timer_sync_user(vcpu);
 			kvm_vgic_sync_hwstate(vcpu);
 			local_irq_enable();
-			preempt_enable();
+			migrate_enable();
 			continue;
 		}
 
@@ -923,7 +923,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		/* Exit types that need handling before we can be preempted */
 		handle_exit_early(vcpu, ret);
 
-		preempt_enable();
+		migrate_enable();
 
 		/*
 		 * The ARMv8 architecture doesn't give the hypervisor
diff --git a/arch/csky/include/asm/spinlock_types.h b/arch/csky/include/asm/spinlock_types.h
index 8ff0f6ff3a006..db87a12c3827d 100644
--- a/arch/csky/include/asm/spinlock_types.h
+++ b/arch/csky/include/asm/spinlock_types.h
@@ -3,7 +3,7 @@
 #ifndef __ASM_CSKY_SPINLOCK_TYPES_H
 #define __ASM_CSKY_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/hexagon/include/asm/spinlock_types.h b/arch/hexagon/include/asm/spinlock_types.h
index 19d233497ba52..d5f66495b670f 100644
--- a/arch/hexagon/include/asm/spinlock_types.h
+++ b/arch/hexagon/include/asm/spinlock_types.h
@@ -8,7 +8,7 @@
 #ifndef _ASM_SPINLOCK_TYPES_H
 #define _ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/ia64/include/asm/spinlock_types.h b/arch/ia64/include/asm/spinlock_types.h
index 6e345fefcdcab..14b8a161c1652 100644
--- a/arch/ia64/include/asm/spinlock_types.h
+++ b/arch/ia64/include/asm/spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef _ASM_IA64_SPINLOCK_TYPES_H
 #define _ASM_IA64_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 27222b75d2a4b..5495225807ebb 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -151,6 +151,7 @@ config PPC
 	select ARCH_STACKWALK
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC	if PPC_BOOK3S || PPC_8xx || 40x
+	select ARCH_SUPPORTS_RT			if HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF		if PPC64
 	select ARCH_USE_MEMTEST
@@ -218,6 +219,7 @@ config PPC
 	select HAVE_HW_BREAKPOINT		if PERF_EVENTS && (PPC_BOOK3S || PPC_8xx)
 	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_TIME_ACCOUNTING
+	select HAVE_POSIX_CPU_TIMERS_TASK_WORK	if !KVM
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA			if DEFAULT_UIMAGE
 	select HAVE_KERNEL_LZO			if DEFAULT_UIMAGE
@@ -234,6 +236,7 @@ config PPC
 	select HAVE_PERF_EVENTS_NMI		if PPC64
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE
 	select HAVE_RSEQ
diff --git a/arch/powerpc/include/asm/simple_spinlock_types.h b/arch/powerpc/include/asm/simple_spinlock_types.h
index 0f3cdd8faa959..08243338069d2 100644
--- a/arch/powerpc/include/asm/simple_spinlock_types.h
+++ b/arch/powerpc/include/asm/simple_spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef _ASM_POWERPC_SIMPLE_SPINLOCK_TYPES_H
 #define _ASM_POWERPC_SIMPLE_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 7ef1cd8168a05..f9e63cacd2209 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -62,6 +62,7 @@ struct smp_ops_t {
 
 extern int smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us);
 extern int smp_send_safe_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us);
+extern void smp_send_debugger_break_cpu(unsigned int cpu);
 extern void smp_send_debugger_break(void);
 extern void start_secondary_resume(void);
 extern void smp_generic_give_timebase(void);
diff --git a/arch/powerpc/include/asm/spinlock_types.h b/arch/powerpc/include/asm/spinlock_types.h
index c5d742f18021d..d5f8a74ed2e8c 100644
--- a/arch/powerpc/include/asm/spinlock_types.h
+++ b/arch/powerpc/include/asm/spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef _ASM_POWERPC_SPINLOCK_TYPES_H
 #define _ASM_POWERPC_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/powerpc/include/asm/stackprotector.h b/arch/powerpc/include/asm/stackprotector.h
index 1c8460e235838..b1653c160bab9 100644
--- a/arch/powerpc/include/asm/stackprotector.h
+++ b/arch/powerpc/include/asm/stackprotector.h
@@ -24,7 +24,11 @@ static __always_inline void boot_init_stack_canary(void)
 	unsigned long canary;
 
 	/* Try to get a semi random initial value. */
+#ifdef CONFIG_PREEMPT_RT
+	canary = (unsigned long)&canary;
+#else
 	canary = get_random_canary();
+#endif
 	canary ^= mftb();
 	canary ^= LINUX_VERSION_CODE;
 	canary &= CANARY_MASK;
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 87013ac2a6401..2920ed3711887 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -53,6 +53,8 @@
 struct thread_info {
 	int		preempt_count;		/* 0 => preemptable,
 						   <0 => BUG */
+	int             preempt_lazy_count;	/* 0 => preemptable,
+						   <0 => BUG */
 	unsigned long	local_flags;		/* private flags for thread */
 #ifdef CONFIG_LIVEPATCH
 	unsigned long *livepatch_sp;
@@ -99,6 +101,7 @@ void arch_setup_new_exec(void);
 #define TIF_PATCH_PENDING	6	/* pending live patching update */
 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
 #define TIF_SINGLESTEP		8	/* singlestepping active */
+#define TIF_NEED_RESCHED_LAZY	9	/* lazy rescheduling necessary */
 #define TIF_SECCOMP		10	/* secure computing */
 #define TIF_RESTOREALL		11	/* Restore all regs (implies NOERROR) */
 #define TIF_NOERROR		12	/* Force successful syscall return */
@@ -114,6 +117,7 @@ void arch_setup_new_exec(void);
 #define TIF_POLLING_NRFLAG	19	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_32BIT		20	/* 32 bit binary */
 
+
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
@@ -125,6 +129,7 @@ void arch_setup_new_exec(void);
 #define _TIF_PATCH_PENDING	(1<<TIF_PATCH_PENDING)
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
+#define _TIF_NEED_RESCHED_LAZY	(1<<TIF_NEED_RESCHED_LAZY)
 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
 #define _TIF_RESTOREALL		(1<<TIF_RESTOREALL)
 #define _TIF_NOERROR		(1<<TIF_NOERROR)
@@ -138,10 +143,12 @@ void arch_setup_new_exec(void);
 				 _TIF_SYSCALL_EMU)
 
 #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+				 _TIF_NEED_RESCHED_LAZY | \
 				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
 				 _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
 				 _TIF_NOTIFY_SIGNAL)
 #define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
+#define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
 
 /* Bits in local_flags */
 /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index c53725a598e5b..35fd5b0728cf0 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -346,7 +346,7 @@ interrupt_exit_user_prepare_main(unsigned long ret, struct pt_regs *regs)
 	ti_flags = READ_ONCE(current_thread_info()->flags);
 	while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {
 		local_irq_enable();
-		if (ti_flags & _TIF_NEED_RESCHED) {
+		if (ti_flags & _TIF_NEED_RESCHED_MASK) {
 			schedule();
 		} else {
 			/*
@@ -550,11 +550,15 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
 		/* Returning to a kernel context with local irqs enabled. */
 		WARN_ON_ONCE(!(regs->msr & MSR_EE));
 again:
-		if (IS_ENABLED(CONFIG_PREEMPT)) {
+		if (IS_ENABLED(CONFIG_PREEMPTION)) {
 			/* Return to preemptible kernel context */
 			if (unlikely(current_thread_info()->flags & _TIF_NEED_RESCHED)) {
 				if (preempt_count() == 0)
 					preempt_schedule_irq();
+			} else if (unlikely(current_thread_info()->flags & _TIF_NEED_RESCHED_LAZY)) {
+				if ((preempt_count() == 0) &&
+				    (current_thread_info()->preempt_lazy_count == 0))
+					preempt_schedule_irq();
 			}
 		}
 
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index c4f1d6b7d9923..02e17a57da83f 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -690,6 +690,7 @@ static inline void check_stack_overflow(void)
 	}
 }
 
+#ifndef CONFIG_PREEMPT_RT
 static __always_inline void call_do_softirq(const void *sp)
 {
 	/* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */
@@ -708,6 +709,7 @@ static __always_inline void call_do_softirq(const void *sp)
 		   "r11", "r12"
 	);
 }
+#endif
 
 static __always_inline void call_do_irq(struct pt_regs *regs, void *sp)
 {
@@ -820,10 +822,12 @@ void *mcheckirq_ctx[NR_CPUS] __read_mostly;
 void *softirq_ctx[NR_CPUS] __read_mostly;
 void *hardirq_ctx[NR_CPUS] __read_mostly;
 
+#ifndef CONFIG_PREEMPT_RT
 void do_softirq_own_stack(void)
 {
 	call_do_softirq(softirq_ctx[smp_processor_id()]);
 }
+#endif
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
 {
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index bdee7262c080a..d57d374978627 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -120,11 +120,19 @@ int kgdb_skipexception(int exception, struct pt_regs *regs)
 
 static int kgdb_debugger_ipi(struct pt_regs *regs)
 {
-	kgdb_nmicallback(raw_smp_processor_id(), regs);
+	int cpu = raw_smp_processor_id();
+
+	if (!kgdb_roundup_delay(cpu))
+		kgdb_nmicallback(cpu, regs);
 	return 0;
 }
 
 #ifdef CONFIG_SMP
+void kgdb_roundup_cpu(unsigned int cpu)
+{
+	smp_send_debugger_break_cpu(cpu);
+}
+
 void kgdb_roundup_cpus(void)
 {
 	smp_send_debugger_break();
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 2b8a5309fb4a5..1cea300257dcc 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -590,6 +590,11 @@ static void debugger_ipi_callback(struct pt_regs *regs)
 	debugger_ipi(regs);
 }
 
+void smp_send_debugger_break_cpu(unsigned int cpu)
+{
+	smp_send_nmi_ipi(cpu, debugger_ipi_callback, 1000000);
+}
+
 void smp_send_debugger_break(void)
 {
 	smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, debugger_ipi_callback, 1000000);
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index f1a2a75c47577..52e66267b0f8c 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -260,12 +260,17 @@ static char *get_mmu_str(void)
 
 static int __die(const char *str, struct pt_regs *regs, long err)
 {
+	const char *pr = "";
+
 	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
 
+	if (IS_ENABLED(CONFIG_PREEMPTION))
+		pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
+
 	printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n",
 	       IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
 	       PAGE_SIZE / 1024, get_mmu_str(),
-	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
+	       pr,
 	       IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
 	       IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
 	       debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index ff581d70f20cf..e5c84d55bdfbc 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -178,6 +178,7 @@ config KVM_E500MC
 config KVM_MPIC
 	bool "KVM in-kernel MPIC emulation"
 	depends on KVM && E500
+	depends on !PREEMPT_RT
 	select HAVE_KVM_IRQCHIP
 	select HAVE_KVM_IRQFD
 	select HAVE_KVM_IRQ_ROUTING
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index aa5f8074e9b10..0cf3bc68baad5 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -24,6 +24,7 @@
 #include <linux/of.h>
 #include <linux/iommu.h>
 #include <linux/rculist.h>
+#include <linux/local_lock.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/rtas.h>
@@ -200,7 +201,13 @@ static int tce_build_pSeriesLP(unsigned long liobn, long tcenum, long tceshift,
 	return ret;
 }
 
-static DEFINE_PER_CPU(__be64 *, tce_page);
+struct tce_page {
+	__be64 * page;
+	local_lock_t lock;
+};
+static DEFINE_PER_CPU(struct tce_page, tce_page) = {
+	.lock = INIT_LOCAL_LOCK(lock),
+};
 
 static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
 				     long npages, unsigned long uaddr,
@@ -223,9 +230,10 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
 		                           direction, attrs);
 	}
 
-	local_irq_save(flags);	/* to protect tcep and the page behind it */
+	/* to protect tcep and the page behind it */
+	local_lock_irqsave(&tce_page.lock, flags);
 
-	tcep = __this_cpu_read(tce_page);
+	tcep = __this_cpu_read(tce_page.page);
 
 	/* This is safe to do since interrupts are off when we're called
 	 * from iommu_alloc{,_sg}()
@@ -234,12 +242,12 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
 		tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
 		/* If allocation fails, fall back to the loop implementation */
 		if (!tcep) {
-			local_irq_restore(flags);
+			local_unlock_irqrestore(&tce_page.lock, flags);
 			return tce_build_pSeriesLP(tbl->it_index, tcenum,
 					tceshift,
 					npages, uaddr, direction, attrs);
 		}
-		__this_cpu_write(tce_page, tcep);
+		__this_cpu_write(tce_page.page, tcep);
 	}
 
 	rpn = __pa(uaddr) >> tceshift;
@@ -269,7 +277,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
 		tcenum += limit;
 	} while (npages > 0 && !rc);
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(&tce_page.lock, flags);
 
 	if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
 		ret = (int)rc;
@@ -454,16 +462,17 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn,
 				DMA_BIDIRECTIONAL, 0);
 	}
 
-	local_irq_disable();	/* to protect tcep and the page behind it */
-	tcep = __this_cpu_read(tce_page);
+	/* to protect tcep and the page behind it */
+	local_lock_irq(&tce_page.lock);
+	tcep = __this_cpu_read(tce_page.page);
 
 	if (!tcep) {
 		tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
 		if (!tcep) {
-			local_irq_enable();
+			local_unlock_irq(&tce_page.lock);
 			return -ENOMEM;
 		}
-		__this_cpu_write(tce_page, tcep);
+		__this_cpu_write(tce_page.page, tcep);
 	}
 
 	proto_tce = TCE_PCI_READ | TCE_PCI_WRITE;
@@ -506,7 +515,7 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn,
 
 	/* error cleanup: caller will clear whole range */
 
-	local_irq_enable();
+	local_unlock_irq(&tce_page.lock);
 	return rc;
 }
 
diff --git a/arch/riscv/include/asm/spinlock_types.h b/arch/riscv/include/asm/spinlock_types.h
index f398e7638dd63..5a35a49505da2 100644
--- a/arch/riscv/include/asm/spinlock_types.h
+++ b/arch/riscv/include/asm/spinlock_types.h
@@ -6,7 +6,7 @@
 #ifndef _ASM_RISCV_SPINLOCK_TYPES_H
 #define _ASM_RISCV_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/s390/include/asm/spinlock_types.h b/arch/s390/include/asm/spinlock_types.h
index a2bbfd7df85fa..b69695e399574 100644
--- a/arch/s390/include/asm/spinlock_types.h
+++ b/arch/s390/include/asm/spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/sh/include/asm/spinlock_types.h b/arch/sh/include/asm/spinlock_types.h
index e82369f286a20..907bda4b1619a 100644
--- a/arch/sh/include/asm/spinlock_types.h
+++ b/arch/sh/include/asm/spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef __ASM_SH_SPINLOCK_TYPES_H
 #define __ASM_SH_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index ef0f0827cf575..2d3eca8fee011 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -149,6 +149,7 @@ void irq_ctx_exit(int cpu)
 	hardirq_ctx[cpu] = NULL;
 }
 
+#ifndef CONFIG_PREEMPT_RT
 void do_softirq_own_stack(void)
 {
 	struct thread_info *curctx;
@@ -176,6 +177,7 @@ void do_softirq_own_stack(void)
 		  "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
 	);
 }
+#endif
 #else
 static inline void handle_one_irq(unsigned int irq)
 {
diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c
index c8848bb681a11..41fa1be980a33 100644
--- a/arch/sparc/kernel/irq_64.c
+++ b/arch/sparc/kernel/irq_64.c
@@ -855,6 +855,7 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs)
 	set_irq_regs(old_regs);
 }
 
+#ifndef CONFIG_PREEMPT_RT
 void do_softirq_own_stack(void)
 {
 	void *orig_sp, *sp = softirq_stack[smp_processor_id()];
@@ -869,6 +870,7 @@ void do_softirq_own_stack(void)
 	__asm__ __volatile__("mov %0, %%sp"
 			     : : "r" (orig_sp));
 }
+#endif
 
 #ifdef CONFIG_HOTPLUG_CPU
 void fixup_irqs(void)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 68a7a1d989f98..624cde3b11fa2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -109,6 +109,7 @@ config X86
 	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
 	select ARCH_SUPPORTS_LTO_CLANG
 	select ARCH_SUPPORTS_LTO_CLANG_THIN
+	select ARCH_SUPPORTS_RT
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_MEMTEST
 	select ARCH_USE_QUEUED_RWLOCKS
@@ -232,6 +233,7 @@ config X86
 	select HAVE_PCI
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
 	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select HAVE_REGS_AND_STACK_ACCESS_API
diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h
index e087cd7837c31..96cc92f63b060 100644
--- a/arch/x86/include/asm/irq_stack.h
+++ b/arch/x86/include/asm/irq_stack.h
@@ -202,6 +202,7 @@
 			      IRQ_CONSTRAINTS, regs, vector);		\
 }
 
+#ifndef CONFIG_PREEMPT_RT
 /*
  * Macro to invoke __do_softirq on the irq stack. This is only called from
  * task context when bottom halves are about to be reenabled and soft
@@ -215,6 +216,8 @@
 	__this_cpu_write(hardirq_stack_inuse, false);			\
 }
 
+#endif
+
 #else /* CONFIG_X86_64 */
 /* System vector handlers always run on the stack they interrupted. */
 #define run_sysvec_on_irqstack_cond(func, regs)				\
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index fe5efbcba8240..ab8cb5fc2329e 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -90,17 +90,48 @@ static __always_inline void __preempt_count_sub(int val)
  * a decrement which hits zero means we have no preempt_count and should
  * reschedule.
  */
-static __always_inline bool __preempt_count_dec_and_test(void)
+static __always_inline bool ____preempt_count_dec_and_test(void)
 {
 	return GEN_UNARY_RMWcc("decl", __preempt_count, e, __percpu_arg([var]));
 }
 
+static __always_inline bool __preempt_count_dec_and_test(void)
+{
+	if (____preempt_count_dec_and_test())
+		return true;
+#ifdef CONFIG_PREEMPT_LAZY
+	if (preempt_count())
+		return false;
+	if (current_thread_info()->preempt_lazy_count)
+		return false;
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+#else
+	return false;
+#endif
+}
+
 /*
  * Returns true when we need to resched and can (barring IRQ state).
  */
 static __always_inline bool should_resched(int preempt_offset)
 {
+#ifdef CONFIG_PREEMPT_LAZY
+	u32 tmp;
+	tmp = raw_cpu_read_4(__preempt_count);
+	if (tmp == preempt_offset)
+		return true;
+
+	/* preempt count == 0 ? */
+	tmp &= ~PREEMPT_NEED_RESCHED;
+	if (tmp != preempt_offset)
+		return false;
+	/* XXX PREEMPT_LOCK_OFFSET */
+	if (current_thread_info()->preempt_lazy_count)
+		return false;
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+#else
 	return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset);
+#endif
 }
 
 #ifdef CONFIG_PREEMPTION
diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index 2dfb5fea13aff..fc03f4f7ed84c 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -28,6 +28,19 @@ typedef struct {
 #define SA_IA32_ABI	0x02000000u
 #define SA_X32_ABI	0x01000000u
 
+/*
+ * Because some traps use the IST stack, we must keep preemption
+ * disabled while calling do_trap(), but do_trap() may call
+ * force_sig_info() which will grab the signal spin_locks for the
+ * task, which in PREEMPT_RT are mutexes.  By defining
+ * ARCH_RT_DELAYS_SIGNAL_SEND the force_sig_info() will set
+ * TIF_NOTIFY_RESUME and set up the signal to be sent on exit of the
+ * trap.
+ */
+#if defined(CONFIG_PREEMPT_RT)
+#define ARCH_RT_DELAYS_SIGNAL_SEND
+#endif
+
 #ifndef CONFIG_COMPAT
 #define compat_sigset_t compat_sigset_t
 typedef sigset_t compat_sigset_t;
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index 24a8d6c4fb185..2fc22c27df183 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -50,7 +50,7 @@
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	u64 canary;
+	u64 canary = 0;
 	u64 tsc;
 
 #ifdef CONFIG_X86_64
@@ -61,8 +61,14 @@ static __always_inline void boot_init_stack_canary(void)
 	 * of randomness. The TSC only matters for very early init,
 	 * there it already has some randomness on most systems. Later
 	 * on during the bootup the random pool has true entropy too.
+	 * For preempt-rt we need to weaken the randomness a bit, as
+	 * we can't call into the random generator from atomic context
+	 * due to locking constraints. We just leave canary
+	 * uninitialized and use the TSC based randomness on top of it.
 	 */
+#ifndef CONFIG_PREEMPT_RT
 	get_random_bytes(&canary, sizeof(canary));
+#endif
 	tsc = rdtsc();
 	canary += tsc + (tsc << 32UL);
 	canary &= CANARY_MASK;
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index cf132663c2196..75dc786e63656 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -57,11 +57,14 @@ struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	unsigned long		syscall_work;	/* SYSCALL_WORK_ flags */
 	u32			status;		/* thread synchronous flags */
+	int			preempt_lazy_count;	/* 0 => lazy preemptable
+							   <0 => BUG */
 };
 
 #define INIT_THREAD_INFO(tsk)			\
 {						\
 	.flags		= 0,			\
+	.preempt_lazy_count	= 0,		\
 }
 
 #else /* !__ASSEMBLY__ */
@@ -90,6 +93,7 @@ struct thread_info {
 #define TIF_NOTSC		16	/* TSC is not accessible in userland */
 #define TIF_NOTIFY_SIGNAL	17	/* signal notifications exist */
 #define TIF_SLD			18	/* Restore split lock detection on context switch */
+#define TIF_NEED_RESCHED_LAZY	19	/* lazy rescheduling necessary */
 #define TIF_MEMDIE		20	/* is terminating due to OOM killer */
 #define TIF_POLLING_NRFLAG	21	/* idle is polling for TIF_NEED_RESCHED */
 #define TIF_IO_BITMAP		22	/* uses I/O bitmap */
@@ -114,6 +118,7 @@ struct thread_info {
 #define _TIF_NOTSC		(1 << TIF_NOTSC)
 #define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
 #define _TIF_SLD		(1 << TIF_SLD)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_IO_BITMAP		(1 << TIF_IO_BITMAP)
 #define _TIF_SPEC_FORCE_UPDATE	(1 << TIF_SPEC_FORCE_UPDATE)
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 044902d5a3c4a..e5dd6da78713b 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -132,6 +132,7 @@ int irq_init_percpu_irqstack(unsigned int cpu)
 	return 0;
 }
 
+#ifndef CONFIG_PREEMPT_RT
 void do_softirq_own_stack(void)
 {
 	struct irq_stack *irqstk;
@@ -148,6 +149,7 @@ void do_softirq_own_stack(void)
 
 	call_on_stack(__do_softirq, isp);
 }
+#endif
 
 void __handle_irq(struct irq_desc *desc, struct pt_regs *regs)
 {
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 3a43a2dee6581..37bd37cdf2b60 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -502,9 +502,12 @@ static int kgdb_nmi_handler(unsigned int cmd, struct pt_regs *regs)
 		if (atomic_read(&kgdb_active) != -1) {
 			/* KGDB CPU roundup */
 			cpu = raw_smp_processor_id();
-			kgdb_nmicallback(cpu, regs);
-			set_bit(cpu, was_in_debug_nmi);
-			touch_nmi_watchdog();
+
+			if (!kgdb_roundup_delay(cpu)) {
+				kgdb_nmicallback(cpu, regs);
+				set_bit(cpu, was_in_debug_nmi);
+				touch_nmi_watchdog();
+			}
 
 			return NMI_HANDLED;
 		}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bbfc8ccf4fcd9..0c4b96bc89c07 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8733,6 +8733,14 @@ int kvm_arch_init(void *opaque)
 		goto out;
 	}
 
+#ifdef CONFIG_PREEMPT_RT
+	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
+		pr_err("RT requires X86_FEATURE_CONSTANT_TSC\n");
+		r = -EOPNOTSUPP;
+		goto out;
+	}
+#endif
+
 	r = -ENOMEM;
 	x86_fpu_cache = kmem_cache_create("x86_fpu", sizeof(struct fpu),
 					  __alignof__(struct fpu), SLAB_ACCOUNT,
diff --git a/arch/xtensa/include/asm/spinlock_types.h b/arch/xtensa/include/asm/spinlock_types.h
index 64c9389254f13..797aed7df3dd8 100644
--- a/arch/xtensa/include/asm/spinlock_types.h
+++ b/arch/xtensa/include/asm/spinlock_types.h
@@ -2,7 +2,7 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#if !defined(__LINUX_SPINLOCK_TYPES_H) && !defined(__ASM_SPINLOCK_H)
+#if !defined(__LINUX_SPINLOCK_TYPES_RAW_H) && !defined(__ASM_SPINLOCK_H)
 # error "please don't include this file directly"
 #endif
 
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 17795b3ae7f33..ad9b1776a41a2 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1584,14 +1584,14 @@ static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async,
 		return;
 
 	if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
-		int cpu = get_cpu();
+		int cpu = get_cpu_light();
 		if (cpumask_test_cpu(cpu, hctx->cpumask)) {
 			__blk_mq_run_hw_queue(hctx);
-			put_cpu();
+			put_cpu_light();
 			return;
 		}
 
-		put_cpu();
+		put_cpu_light();
 	}
 
 	kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work,
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 2398306ab5ce7..09def097d5442 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -1061,14 +1061,14 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 
 static void crypto_disable_simd_for_test(void)
 {
-	preempt_disable();
+	migrate_disable();
 	__this_cpu_write(crypto_simd_disabled_for_test, true);
 }
 
 static void crypto_reenable_simd_for_test(void)
 {
 	__this_cpu_write(crypto_simd_disabled_for_test, false);
-	preempt_enable();
+	migrate_enable();
 }
 
 /*
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index a9f71b27d235a..ca3dc9f219fdc 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -59,6 +59,40 @@ static void zram_free_page(struct zram *zram, size_t index);
 static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 				u32 index, int offset, struct bio *bio);
 
+#ifdef CONFIG_PREEMPT_RT
+static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages)
+{
+	size_t index;
+
+	for (index = 0; index < num_pages; index++)
+		spin_lock_init(&zram->table[index].lock);
+}
+
+static int zram_slot_trylock(struct zram *zram, u32 index)
+{
+	int ret;
+
+	ret = spin_trylock(&zram->table[index].lock);
+	if (ret)
+		__set_bit(ZRAM_LOCK, &zram->table[index].flags);
+	return ret;
+}
+
+static void zram_slot_lock(struct zram *zram, u32 index)
+{
+	spin_lock(&zram->table[index].lock);
+	__set_bit(ZRAM_LOCK, &zram->table[index].flags);
+}
+
+static void zram_slot_unlock(struct zram *zram, u32 index)
+{
+	__clear_bit(ZRAM_LOCK, &zram->table[index].flags);
+	spin_unlock(&zram->table[index].lock);
+}
+
+#else
+
+static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) { }
 
 static int zram_slot_trylock(struct zram *zram, u32 index)
 {
@@ -74,6 +108,7 @@ static void zram_slot_unlock(struct zram *zram, u32 index)
 {
 	bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags);
 }
+#endif
 
 static inline bool init_done(struct zram *zram)
 {
@@ -1175,6 +1210,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize)
 
 	if (!huge_class_size)
 		huge_class_size = zs_huge_class_size(zram->mem_pool);
+	zram_meta_init_table_locks(zram, num_pages);
 	return true;
 }
 
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 80c3b43b4828f..d8f6d880f9151 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -63,6 +63,7 @@ struct zram_table_entry {
 		unsigned long element;
 	};
 	unsigned long flags;
+	spinlock_t lock;
 #ifdef CONFIG_ZRAM_MEMORY_TRACKING
 	ktime_t ac_time;
 #endif
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index dfb463ee7ca1a..b19c4f745ee38 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -50,6 +50,31 @@ static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *da
 	return container_of(data, struct tpm_tis_tcg_phy, priv);
 }
 
+#ifdef CONFIG_PREEMPT_RT
+/*
+ * Flushes previous write operations to chip so that a subsequent
+ * ioread*()s won't stall a cpu.
+ */
+static inline void tpm_tis_flush(void __iomem *iobase)
+{
+	ioread8(iobase + TPM_ACCESS(0));
+}
+#else
+#define tpm_tis_flush(iobase) do { } while (0)
+#endif
+
+static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr)
+{
+	iowrite8(b, iobase + addr);
+	tpm_tis_flush(iobase);
+}
+
+static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr)
+{
+	iowrite32(b, iobase + addr);
+	tpm_tis_flush(iobase);
+}
+
 static int interrupts = -1;
 module_param(interrupts, int, 0444);
 MODULE_PARM_DESC(interrupts, "Enable interrupts");
@@ -186,7 +211,7 @@ static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 
 	while (len--)
-		iowrite8(*value++, phy->iobase + addr);
+		tpm_tis_iowrite8(*value++, phy->iobase, addr);
 
 	return 0;
 }
@@ -213,7 +238,7 @@ static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value)
 {
 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 
-	iowrite32(value, phy->iobase + addr);
+	tpm_tis_iowrite32(value, phy->iobase, addr);
 
 	return 0;
 }
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 8c86b3c1df0d7..78b3e5f0aba4c 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -66,7 +66,7 @@ struct mm_struct efi_mm = {
 
 struct workqueue_struct *efi_rts_wq;
 
-static bool disable_runtime;
+static bool disable_runtime = IS_ENABLED(CONFIG_PREEMPT_RT);
 static int __init setup_noefi(char *arg)
 {
 	disable_runtime = true;
@@ -97,6 +97,9 @@ static int __init parse_efi_cmdline(char *str)
 	if (parse_option_str(str, "noruntime"))
 		disable_runtime = true;
 
+	if (parse_option_str(str, "runtime"))
+		disable_runtime = false;
+
 	if (parse_option_str(str, "nosoftreserve"))
 		set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
 
diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index 254e67141a776..7a39029b083f4 100644
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -425,7 +425,8 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
 	 */
 	intel_psr_wait_for_idle(new_crtc_state);
 
-	local_irq_disable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_irq_disable();
 
 	crtc->debug.min_vbl = min;
 	crtc->debug.max_vbl = max;
@@ -450,11 +451,13 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
 			break;
 		}
 
-		local_irq_enable();
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+			local_irq_enable();
 
 		timeout = schedule_timeout(timeout);
 
-		local_irq_disable();
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+			local_irq_disable();
 	}
 
 	finish_wait(wq, &wait);
@@ -487,7 +490,8 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
 	return;
 
 irq_disable:
-	local_irq_disable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_irq_disable();
 }
 
 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_VBLANK_EVADE)
@@ -566,7 +570,8 @@ void intel_pipe_update_end(struct intel_crtc_state *new_crtc_state)
 		new_crtc_state->uapi.event = NULL;
 	}
 
-	local_irq_enable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_irq_enable();
 
 	/* Send VRR Push to terminate Vblank */
 	intel_vrr_send_push(new_crtc_state);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index c410989507466..601274ba86e46 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -163,7 +163,8 @@ static inline void intel_context_enter(struct intel_context *ce)
 
 static inline void intel_context_mark_active(struct intel_context *ce)
 {
-	lockdep_assert_held(&ce->timeline->mutex);
+	lockdep_assert(lockdep_is_held(&ce->timeline->mutex) ||
+		       test_bit(CONTEXT_IS_PARKED, &ce->flags));
 	++ce->active_count;
 }
 
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index a63631ea0ec47..314457fb9db5e 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -112,6 +112,7 @@ struct intel_context {
 #define CONTEXT_FORCE_SINGLE_SUBMISSION	7
 #define CONTEXT_NOPREEMPT		8
 #define CONTEXT_LRCA_DIRTY		9
+#define CONTEXT_IS_PARKED		10
 
 	struct {
 		u64 timeout_us;
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
index 5a90969067950..7ddfc9744cdfa 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -80,39 +80,6 @@ static int __engine_unpark(struct intel_wakeref *wf)
 	return 0;
 }
 
-#if IS_ENABLED(CONFIG_LOCKDEP)
-
-static unsigned long __timeline_mark_lock(struct intel_context *ce)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	mutex_acquire(&ce->timeline->mutex.dep_map, 2, 0, _THIS_IP_);
-
-	return flags;
-}
-
-static void __timeline_mark_unlock(struct intel_context *ce,
-				   unsigned long flags)
-{
-	mutex_release(&ce->timeline->mutex.dep_map, _THIS_IP_);
-	local_irq_restore(flags);
-}
-
-#else
-
-static unsigned long __timeline_mark_lock(struct intel_context *ce)
-{
-	return 0;
-}
-
-static void __timeline_mark_unlock(struct intel_context *ce,
-				   unsigned long flags)
-{
-}
-
-#endif /* !IS_ENABLED(CONFIG_LOCKDEP) */
-
 static void duration(struct dma_fence *fence, struct dma_fence_cb *cb)
 {
 	struct i915_request *rq = to_request(fence);
@@ -159,7 +126,6 @@ static bool switch_to_kernel_context(struct intel_engine_cs *engine)
 {
 	struct intel_context *ce = engine->kernel_context;
 	struct i915_request *rq;
-	unsigned long flags;
 	bool result = true;
 
 	/* GPU is pointing to the void, as good as in the kernel context. */
@@ -201,7 +167,7 @@ static bool switch_to_kernel_context(struct intel_engine_cs *engine)
 	 * engine->wakeref.count, we may see the request completion and retire
 	 * it causing an underflow of the engine->wakeref.
 	 */
-	flags = __timeline_mark_lock(ce);
+	set_bit(CONTEXT_IS_PARKED, &ce->flags);
 	GEM_BUG_ON(atomic_read(&ce->timeline->active_count) < 0);
 
 	rq = __i915_request_create(ce, GFP_NOWAIT);
@@ -233,7 +199,7 @@ static bool switch_to_kernel_context(struct intel_engine_cs *engine)
 
 	result = false;
 out_unlock:
-	__timeline_mark_unlock(ce, flags);
+	clear_bit(CONTEXT_IS_PARKED, &ce->flags);
 	return result;
 }
 
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 02b353641eab6..80af6ce902b90 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -1286,7 +1286,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 	 * and context switches) submission.
 	 */
 
-	spin_lock(&sched_engine->lock);
+	spin_lock_irq(&sched_engine->lock);
 
 	/*
 	 * If the queue is higher priority than the last
@@ -1386,7 +1386,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 				 * Even if ELSP[1] is occupied and not worthy
 				 * of timeslices, our queue might be.
 				 */
-				spin_unlock(&sched_engine->lock);
+				spin_unlock_irq(&sched_engine->lock);
 				return;
 			}
 		}
@@ -1412,7 +1412,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 
 		if (last && !can_merge_rq(last, rq)) {
 			spin_unlock(&ve->base.sched_engine->lock);
-			spin_unlock(&engine->sched_engine->lock);
+			spin_unlock_irq(&engine->sched_engine->lock);
 			return; /* leave this for another sibling */
 		}
 
@@ -1574,7 +1574,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 	 */
 	sched_engine->queue_priority_hint = queue_prio(sched_engine);
 	i915_sched_engine_reset_on_empty(sched_engine);
-	spin_unlock(&sched_engine->lock);
+	spin_unlock_irq(&sched_engine->lock);
 
 	/*
 	 * We can skip poking the HW if we ended up with exactly the same set
@@ -1600,13 +1600,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 	}
 }
 
-static void execlists_dequeue_irq(struct intel_engine_cs *engine)
-{
-	local_irq_disable(); /* Suspend interrupts across request submission */
-	execlists_dequeue(engine);
-	local_irq_enable(); /* flush irq_work (e.g. breadcrumb enabling) */
-}
-
 static void clear_ports(struct i915_request **ports, int count)
 {
 	memset_p((void **)ports, NULL, count);
@@ -2442,7 +2435,7 @@ static void execlists_submission_tasklet(struct tasklet_struct *t)
 	}
 
 	if (!engine->execlists.pending[0]) {
-		execlists_dequeue_irq(engine);
+		execlists_dequeue(engine);
 		start_timeslice(engine);
 	}
 
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index 113a203af258b..9da7819373b15 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -168,13 +168,13 @@ static int i915_do_reset(struct intel_gt *gt,
 	/* Assert reset for at least 20 usec, and wait for acknowledgement. */
 	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
 	udelay(50);
-	err = wait_for_atomic(i915_in_reset(pdev), 50);
+	err = _wait_for_atomic(i915_in_reset(pdev), 50, 0);
 
 	/* Clear the reset request. */
 	pci_write_config_byte(pdev, I915_GDRST, 0);
 	udelay(50);
 	if (!err)
-		err = wait_for_atomic(!i915_in_reset(pdev), 50);
+		err = _wait_for_atomic(!i915_in_reset(pdev), 50, 0);
 
 	return err;
 }
@@ -194,7 +194,7 @@ static int g33_do_reset(struct intel_gt *gt,
 	struct pci_dev *pdev = to_pci_dev(gt->i915->drm.dev);
 
 	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
-	return wait_for_atomic(g4x_reset_complete(pdev), 50);
+	return _wait_for_atomic(g4x_reset_complete(pdev), 50, 0);
 }
 
 static int g4x_do_reset(struct intel_gt *gt,
@@ -211,7 +211,7 @@ static int g4x_do_reset(struct intel_gt *gt,
 
 	pci_write_config_byte(pdev, I915_GDRST,
 			      GRDOM_MEDIA | GRDOM_RESET_ENABLE);
-	ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
+	ret =  _wait_for_atomic(g4x_reset_complete(pdev), 50, 0);
 	if (ret) {
 		GT_TRACE(gt, "Wait for media reset failed\n");
 		goto out;
@@ -219,7 +219,7 @@ static int g4x_do_reset(struct intel_gt *gt,
 
 	pci_write_config_byte(pdev, I915_GDRST,
 			      GRDOM_RENDER | GRDOM_RESET_ENABLE);
-	ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
+	ret =  _wait_for_atomic(g4x_reset_complete(pdev), 50, 0);
 	if (ret) {
 		GT_TRACE(gt, "Wait for render reset failed\n");
 		goto out;
@@ -737,9 +737,7 @@ int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask)
 	intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
 	for (retry = 0; ret == -ETIMEDOUT && retry < retries; retry++) {
 		GT_TRACE(gt, "engine_mask=%x\n", engine_mask);
-		preempt_disable();
 		ret = reset(gt, engine_mask, retry);
-		preempt_enable();
 	}
 	intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
 
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 9bc4f4a8e12ec..547347241a47c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -886,7 +886,8 @@ static bool i915_get_crtc_scanoutpos(struct drm_crtc *_crtc,
 	 */
 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
-	/* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_disable();
 
 	/* Get optional system timestamp before query. */
 	if (stime)
@@ -950,7 +951,8 @@ static bool i915_get_crtc_scanoutpos(struct drm_crtc *_crtc,
 	if (etime)
 		*etime = ktime_get();
 
-	/* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_enable();
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index bd85113ad150c..197aac225aa24 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -559,7 +559,6 @@ bool __i915_request_submit(struct i915_request *request)
 
 	RQ_TRACE(request, "\n");
 
-	GEM_BUG_ON(!irqs_disabled());
 	lockdep_assert_held(&engine->sched_engine->lock);
 
 	/*
@@ -668,7 +667,6 @@ void __i915_request_unsubmit(struct i915_request *request)
 	 */
 	RQ_TRACE(request, "\n");
 
-	GEM_BUG_ON(!irqs_disabled());
 	lockdep_assert_held(&engine->sched_engine->lock);
 
 	/*
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 1bc1349ba3c25..a2f713b4ac2f9 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -609,7 +609,8 @@ i915_request_timeline(const struct i915_request *rq)
 {
 	/* Valid only while the request is being constructed (or retired). */
 	return rcu_dereference_protected(rq->timeline,
-					 lockdep_is_held(&rcu_access_pointer(rq->timeline)->mutex));
+					 lockdep_is_held(&rcu_access_pointer(rq->timeline)->mutex) ||
+					 test_bit(CONTEXT_IS_PARKED, &rq->context->flags));
 }
 
 static inline struct i915_gem_context *
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index 63fec1c3c132d..f345a0f12bf6e 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -2,6 +2,10 @@
 #if !defined(_I915_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ)
 #define _I915_TRACE_H_
 
+#ifdef CONFIG_PREEMPT_RT
+#define NOTRACE
+#endif
+
 #include <linux/stringify.h>
 #include <linux/types.h>
 #include <linux/tracepoint.h>
@@ -819,7 +823,7 @@ DEFINE_EVENT(i915_request, i915_request_add,
 	     TP_ARGS(rq)
 );
 
-#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS)
+#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS) && !defined(NOTRACE)
 DEFINE_EVENT(i915_request, i915_request_guc_submit,
 	     TP_PROTO(struct i915_request *rq),
 	     TP_ARGS(rq)
diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
index 5259edacde380..b36b27c090496 100644
--- a/drivers/gpu/drm/i915/i915_utils.h
+++ b/drivers/gpu/drm/i915/i915_utils.h
@@ -343,7 +343,7 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 #define wait_for(COND, MS)		_wait_for((COND), (MS) * 1000, 10, 1000)
 
 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
-#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
+#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT) && !defined(CONFIG_PREEMPT_RT)
 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
 #else
 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
diff --git a/drivers/i2c/busses/i2c-cht-wc.c b/drivers/i2c/busses/i2c-cht-wc.c
index 1cf68f85b2e11..8ccf0c928bb44 100644
--- a/drivers/i2c/busses/i2c-cht-wc.c
+++ b/drivers/i2c/busses/i2c-cht-wc.c
@@ -99,15 +99,8 @@ static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data)
 	 * interrupt handler as well, so running the client irq handler from
 	 * this thread will cause things to lock up.
 	 */
-	if (reg & CHT_WC_EXTCHGRIRQ_CLIENT_IRQ) {
-		/*
-		 * generic_handle_irq expects local IRQs to be disabled
-		 * as normally it is called from interrupt context.
-		 */
-		local_irq_disable();
-		generic_handle_irq(adap->client_irq);
-		local_irq_enable();
-	}
+	if (reg & CHT_WC_EXTCHGRIRQ_CLIENT_IRQ)
+		generic_handle_irq_safe(adap->client_irq);
 
 	return IRQ_HANDLED;
 }
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index becb95a753289..edcd639e82ef7 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1503,7 +1503,7 @@ int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
 	if (irq <= 0)
 		return -ENXIO;
 
-	generic_handle_irq(irq);
+	generic_handle_irq_safe(irq);
 
 	return 0;
 }
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index 1f1d572880859..dc6816d36d069 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig
@@ -64,6 +64,7 @@ config LEDS_TRIGGER_BACKLIGHT
 
 config LEDS_TRIGGER_CPU
 	bool "LED CPU Trigger"
+	depends on !PREEMPT_RT
 	help
 	  This allows LEDs to be controlled by active CPUs. This shows
 	  the active CPUs across an array of LEDs so you can see which
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a957eb3ce7bc6..e4b27ba45554a 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2217,8 +2217,9 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
 	struct raid5_percpu *percpu;
 	unsigned long cpu;
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	percpu = per_cpu_ptr(conf->percpu, cpu);
+	spin_lock(&percpu->lock);
 	if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
 		ops_run_biofill(sh);
 		overlap_clear++;
@@ -2277,7 +2278,8 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
 			if (test_and_clear_bit(R5_Overlap, &dev->flags))
 				wake_up(&sh->raid_conf->wait_for_overlap);
 		}
-	put_cpu();
+	spin_unlock(&percpu->lock);
+	put_cpu_light();
 }
 
 static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh)
@@ -7113,6 +7115,7 @@ static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
 			__func__, cpu);
 		return -ENOMEM;
 	}
+	spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock);
 	return 0;
 }
 
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 5c05acf20e1f2..665fe138ab4f7 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -635,6 +635,7 @@ struct r5conf {
 	int			recovery_disabled;
 	/* per cpu variables */
 	struct raid5_percpu {
+		spinlock_t	lock;		/* Protection for -RT */
 		struct page	*spare_page; /* Used when checking P/Q in raid6 */
 		void		*scribble;  /* space for constructing buffer
 					     * lists and performing address
diff --git a/drivers/mfd/ezx-pcap.c b/drivers/mfd/ezx-pcap.c
index 70fa18b04ad2b..b14d3f98e1ebd 100644
--- a/drivers/mfd/ezx-pcap.c
+++ b/drivers/mfd/ezx-pcap.c
@@ -193,13 +193,11 @@ static void pcap_isr_work(struct work_struct *work)
 		ezx_pcap_write(pcap, PCAP_REG_MSR, isr | msr);
 		ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
 
-		local_irq_disable();
 		service = isr & ~msr;
 		for (irq = pcap->irq_base; service; service >>= 1, irq++) {
 			if (service & 1)
-				generic_handle_irq(irq);
+				generic_handle_irq_safe(irq);
 		}
-		local_irq_enable();
 		ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
 	} while (gpio_get_value(pdata->gpio));
 }
diff --git a/drivers/misc/hi6421v600-irq.c b/drivers/misc/hi6421v600-irq.c
index 08535e97ff433..0585a5821d059 100644
--- a/drivers/misc/hi6421v600-irq.c
+++ b/drivers/misc/hi6421v600-irq.c
@@ -118,8 +118,8 @@ static irqreturn_t hi6421v600_irq_handler(int irq, void *__priv)
 			 * If both powerkey down and up IRQs are received,
 			 * handle them at the right order
 			 */
-			generic_handle_irq(priv->irqs[POWERKEY_DOWN]);
-			generic_handle_irq(priv->irqs[POWERKEY_UP]);
+			generic_handle_irq_safe(priv->irqs[POWERKEY_DOWN]);
+			generic_handle_irq_safe(priv->irqs[POWERKEY_UP]);
 			pending &= ~HISI_IRQ_POWERKEY_UP_DOWN;
 		}
 
@@ -127,7 +127,7 @@ static irqreturn_t hi6421v600_irq_handler(int irq, void *__priv)
 			continue;
 
 		for_each_set_bit(offset, &pending, BITS_PER_BYTE) {
-			generic_handle_irq(priv->irqs[offset + i * BITS_PER_BYTE]);
+			generic_handle_irq_safe(priv->irqs[offset + i * BITS_PER_BYTE]);
 		}
 	}
 
diff --git a/drivers/net/ethernet/netronome/nfp/abm/qdisc.c b/drivers/net/ethernet/netronome/nfp/abm/qdisc.c
index 2473fb5f75e5e..2a5cc64227e9f 100644
--- a/drivers/net/ethernet/netronome/nfp/abm/qdisc.c
+++ b/drivers/net/ethernet/netronome/nfp/abm/qdisc.c
@@ -458,7 +458,7 @@ nfp_abm_qdisc_graft(struct nfp_abm_link *alink, u32 handle, u32 child_handle,
 static void
 nfp_abm_stats_calculate(struct nfp_alink_stats *new,
 			struct nfp_alink_stats *old,
-			struct gnet_stats_basic_packed *bstats,
+			struct gnet_stats_basic_sync *bstats,
 			struct gnet_stats_queue *qstats)
 {
 	_bstats_update(bstats, new->tx_bytes - old->tx_bytes,
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 511d7faa9e37b..94a17b4131246 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1380,11 +1380,8 @@ static void lan78xx_status(struct lan78xx_net *dev, struct urb *urb)
 		netif_dbg(dev, link, dev->net, "PHY INTR: 0x%08x\n", intdata);
 		lan78xx_defer_kevent(dev, EVENT_LINK_RESET);
 
-		if (dev->domain_data.phyirq > 0) {
-			local_irq_disable();
-			generic_handle_irq(dev->domain_data.phyirq);
-			local_irq_enable();
-		}
+		if (dev->domain_data.phyirq > 0)
+			generic_handle_irq_safe(dev->domain_data.phyirq);
 	} else {
 		netdev_warn(dev->net,
 			    "unexpected interrupt: 0x%08x\n", intdata);
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 76dbdae0e9874..967431858dcd3 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -1450,11 +1450,11 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev,
 static int fcoe_alloc_paged_crc_eof(struct sk_buff *skb, int tlen)
 {
 	struct fcoe_percpu_s *fps;
-	int rc;
+	int rc, cpu = get_cpu_light();
 
-	fps = &get_cpu_var(fcoe_percpu);
+	fps = &per_cpu(fcoe_percpu, cpu);
 	rc = fcoe_get_paged_crc_eof(skb, tlen, fps);
-	put_cpu_var(fcoe_percpu);
+	put_cpu_light();
 
 	return rc;
 }
@@ -1639,11 +1639,11 @@ static inline int fcoe_filter_frames(struct fc_lport *lport,
 		return 0;
 	}
 
-	stats = per_cpu_ptr(lport->stats, get_cpu());
+	stats = per_cpu_ptr(lport->stats, get_cpu_light());
 	stats->InvalidCRCCount++;
 	if (stats->InvalidCRCCount < 5)
 		printk(KERN_WARNING "fcoe: dropping frame with CRC error\n");
-	put_cpu();
+	put_cpu_light();
 	return -EINVAL;
 }
 
@@ -1684,7 +1684,7 @@ static void fcoe_recv_frame(struct sk_buff *skb)
 	 */
 	hp = (struct fcoe_hdr *) skb_network_header(skb);
 
-	stats = per_cpu_ptr(lport->stats, get_cpu());
+	stats = per_cpu_ptr(lport->stats, get_cpu_light());
 	if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
 		if (stats->ErrorFrames < 5)
 			printk(KERN_WARNING "fcoe: FCoE version "
@@ -1716,13 +1716,13 @@ static void fcoe_recv_frame(struct sk_buff *skb)
 		goto drop;
 
 	if (!fcoe_filter_frames(lport, fp)) {
-		put_cpu();
+		put_cpu_light();
 		fc_exch_recv(lport, fp);
 		return;
 	}
 drop:
 	stats->ErrorFrames++;
-	put_cpu();
+	put_cpu_light();
 	kfree_skb(skb);
 }
 
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index ba1c9bd2fb9d9..6589000825e17 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -828,7 +828,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
 
 	INIT_LIST_HEAD(&del_list);
 
-	stats = per_cpu_ptr(fip->lp->stats, get_cpu());
+	stats = per_cpu_ptr(fip->lp->stats, get_cpu_light());
 
 	list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
 		deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
@@ -864,7 +864,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
 				sel_time = fcf->time;
 		}
 	}
-	put_cpu();
+	put_cpu_light();
 
 	list_for_each_entry_safe(fcf, next, &del_list, list) {
 		/* Removes fcf from current list */
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index aa223db4cf53c..0ceb93800704b 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -825,10 +825,10 @@ static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
 	}
 	memset(ep, 0, sizeof(*ep));
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	pool = per_cpu_ptr(mp->pool, cpu);
 	spin_lock_bh(&pool->lock);
-	put_cpu();
+	put_cpu_light();
 
 	/* peek cache of free slot */
 	if (pool->left != FC_XID_UNKNOWN) {
diff --git a/drivers/staging/greybus/gpio.c b/drivers/staging/greybus/gpio.c
index 7e6347fe93f99..8a7cf1d0e9688 100644
--- a/drivers/staging/greybus/gpio.c
+++ b/drivers/staging/greybus/gpio.c
@@ -391,10 +391,7 @@ static int gb_gpio_request_handler(struct gb_operation *op)
 		return -EINVAL;
 	}
 
-	local_irq_disable();
-	ret = generic_handle_irq(irq);
-	local_irq_enable();
-
+	ret = generic_handle_irq_safe(irq);
 	if (ret)
 		dev_err(dev, "failed to invoke irq handler\n");
 
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 6e9d6c489813f..017987a56a690 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -155,12 +155,55 @@ static inline void serial_dl_write(struct uart_8250_port *up, int value)
 	up->dl_write(up, value);
 }
 
+static inline void serial8250_set_IER(struct uart_8250_port *up,
+				      unsigned char ier)
+{
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	bool is_console;
+
+	is_console = uart_console(port);
+
+	if (is_console)
+		console_atomic_lock(flags);
+
+	serial_out(up, UART_IER, ier);
+
+	if (is_console)
+		console_atomic_unlock(flags);
+}
+
+static inline unsigned char serial8250_clear_IER(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	unsigned int clearval = 0;
+	unsigned long flags;
+	unsigned int prior;
+	bool is_console;
+
+	is_console = uart_console(port);
+
+	if (up->capabilities & UART_CAP_UUE)
+		clearval = UART_IER_UUE;
+
+	if (is_console)
+		console_atomic_lock(flags);
+
+	prior = serial_port_in(port, UART_IER);
+	serial_port_out(port, UART_IER, clearval);
+
+	if (is_console)
+		console_atomic_unlock(flags);
+
+	return prior;
+}
+
 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
 {
 	if (up->ier & UART_IER_THRI)
 		return false;
 	up->ier |= UART_IER_THRI;
-	serial_out(up, UART_IER, up->ier);
+	serial8250_set_IER(up, up->ier);
 	return true;
 }
 
@@ -169,7 +212,7 @@ static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
 	if (!(up->ier & UART_IER_THRI))
 		return false;
 	up->ier &= ~UART_IER_THRI;
-	serial_out(up, UART_IER, up->ier);
+	serial8250_set_IER(up, up->ier);
 	return true;
 }
 
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 1890f342f090a..16d5d450b32fc 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -265,10 +265,8 @@ static void serial8250_backup_timeout(struct timer_list *t)
 	 * Must disable interrupts or else we risk racing with the interrupt
 	 * based handler.
 	 */
-	if (up->port.irq) {
-		ier = serial_in(up, UART_IER);
-		serial_out(up, UART_IER, 0);
-	}
+	if (up->port.irq)
+		ier = serial8250_clear_IER(up);
 
 	iir = serial_in(up, UART_IIR);
 
@@ -291,7 +289,7 @@ static void serial8250_backup_timeout(struct timer_list *t)
 		serial8250_tx_chars(up);
 
 	if (up->port.irq)
-		serial_out(up, UART_IER, ier);
+		serial8250_set_IER(up, ier);
 
 	spin_unlock_irqrestore(&up->port.lock, flags);
 
@@ -578,6 +576,14 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
 
 #ifdef CONFIG_SERIAL_8250_CONSOLE
 
+static void univ8250_console_write_atomic(struct console *co, const char *s,
+					  unsigned int count)
+{
+	struct uart_8250_port *up = &serial8250_ports[co->index];
+
+	serial8250_console_write_atomic(up, s, count);
+}
+
 static void univ8250_console_write(struct console *co, const char *s,
 				   unsigned int count)
 {
@@ -671,6 +677,7 @@ static int univ8250_console_match(struct console *co, char *name, int idx,
 
 static struct console univ8250_console = {
 	.name		= "ttyS",
+	.write_atomic	= univ8250_console_write_atomic,
 	.write		= univ8250_console_write,
 	.device		= uart_console_device,
 	.setup		= univ8250_console_setup,
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
index 6a22f3a970f35..a6c02140eff02 100644
--- a/drivers/tty/serial/8250/8250_fsl.c
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -60,9 +60,18 @@ int fsl8250_handle_irq(struct uart_port *port)
 
 	/* Stop processing interrupts on input overrun */
 	if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
+		unsigned long flags;
 		unsigned long delay;
+		bool is_console;
 
+		is_console = uart_console(port);
+
+		if (is_console)
+			console_atomic_lock(flags);
 		up->ier = port->serial_in(port, UART_IER);
+		if (is_console)
+			console_atomic_unlock(flags);
+
 		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
 			port->ops->stop_rx(port);
 		} else {
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index 65402d05eff93..8122645ab05c9 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -146,6 +146,8 @@ OF_EARLYCON_DECLARE(x1000_uart, "ingenic,x1000-uart",
 
 static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
 {
+	unsigned long flags;
+	bool is_console;
 	int ier;
 
 	switch (offset) {
@@ -167,7 +169,12 @@ static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
 		 * If we have enabled modem status IRQs we should enable
 		 * modem mode.
 		 */
+		is_console = uart_console(p);
+		if (is_console)
+			console_atomic_lock(flags);
 		ier = p->serial_in(p, UART_IER);
+		if (is_console)
+			console_atomic_unlock(flags);
 
 		if (ier & UART_IER_MSI)
 			value |= UART_MCR_MDCE | UART_MCR_FCM;
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index de48a58460f47..364ee950f21ac 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -222,12 +222,37 @@ static void mtk8250_shutdown(struct uart_port *port)
 
 static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
 {
-	serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int ier;
+	bool is_console;
+
+	is_console = uart_console(port);
+
+	if (is_console)
+		console_atomic_lock(flags);
+
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, ier & (~mask));
+
+	if (is_console)
+		console_atomic_unlock(flags);
 }
 
 static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
 {
-	serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int ier;
+
+	if (uart_console(port))
+		console_atomic_lock(flags);
+
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, ier | mask);
+
+	if (uart_console(port))
+		console_atomic_unlock(flags);
 }
 
 static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3e9b42c2860bc..daf5462fe0bc5 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -738,7 +738,7 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
 			serial_out(p, UART_EFR, UART_EFR_ECB);
 			serial_out(p, UART_LCR, 0);
 		}
-		serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
+		serial8250_set_IER(p, sleep ? UART_IERX_SLEEP : 0);
 		if (p->capabilities & UART_CAP_EFR) {
 			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
 			serial_out(p, UART_EFR, efr);
@@ -1407,7 +1407,7 @@ static void serial8250_stop_rx(struct uart_port *port)
 
 	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
 	up->port.read_status_mask &= ~UART_LSR_DR;
-	serial_port_out(port, UART_IER, up->ier);
+	serial8250_set_IER(up, up->ier);
 
 	serial8250_rpm_put(up);
 }
@@ -1437,7 +1437,7 @@ void serial8250_em485_stop_tx(struct uart_8250_port *p)
 		serial8250_clear_and_reinit_fifos(p);
 
 		p->ier |= UART_IER_RLSI | UART_IER_RDI;
-		serial_port_out(&p->port, UART_IER, p->ier);
+		serial8250_set_IER(p, p->ier);
 	}
 }
 EXPORT_SYMBOL_GPL(serial8250_em485_stop_tx);
@@ -1673,7 +1673,7 @@ static void serial8250_disable_ms(struct uart_port *port)
 	mctrl_gpio_disable_ms(up->gpios);
 
 	up->ier &= ~UART_IER_MSI;
-	serial_port_out(port, UART_IER, up->ier);
+	serial8250_set_IER(up, up->ier);
 }
 
 static void serial8250_enable_ms(struct uart_port *port)
@@ -1689,7 +1689,7 @@ static void serial8250_enable_ms(struct uart_port *port)
 	up->ier |= UART_IER_MSI;
 
 	serial8250_rpm_get(up);
-	serial_port_out(port, UART_IER, up->ier);
+	serial8250_set_IER(up, up->ier);
 	serial8250_rpm_put(up);
 }
 
@@ -2126,14 +2126,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
 	struct uart_8250_port *up = up_to_u8250p(port);
 
 	serial8250_rpm_get(up);
-	/*
-	 *	First save the IER then disable the interrupts
-	 */
-	ier = serial_port_in(port, UART_IER);
-	if (up->capabilities & UART_CAP_UUE)
-		serial_port_out(port, UART_IER, UART_IER_UUE);
-	else
-		serial_port_out(port, UART_IER, 0);
+	ier = serial8250_clear_IER(up);
 
 	wait_for_xmitr(up, BOTH_EMPTY);
 	/*
@@ -2146,7 +2139,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
 	 *	and restore the IER
 	 */
 	wait_for_xmitr(up, BOTH_EMPTY);
-	serial_port_out(port, UART_IER, ier);
+	serial8250_set_IER(up, ier);
 	serial8250_rpm_put(up);
 }
 
@@ -2450,7 +2443,7 @@ void serial8250_do_shutdown(struct uart_port *port)
 	 */
 	spin_lock_irqsave(&port->lock, flags);
 	up->ier = 0;
-	serial_port_out(port, UART_IER, 0);
+	serial8250_set_IER(up, 0);
 	spin_unlock_irqrestore(&port->lock, flags);
 
 	synchronize_irq(port->irq);
@@ -2842,7 +2835,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (up->capabilities & UART_CAP_RTOIE)
 		up->ier |= UART_IER_RTOIE;
 
-	serial_port_out(port, UART_IER, up->ier);
+	serial8250_set_IER(up, up->ier);
 
 	if (up->capabilities & UART_CAP_EFR) {
 		unsigned char efr = 0;
@@ -3308,7 +3301,7 @@ EXPORT_SYMBOL_GPL(serial8250_set_defaults);
 
 #ifdef CONFIG_SERIAL_8250_CONSOLE
 
-static void serial8250_console_putchar(struct uart_port *port, int ch)
+static void serial8250_console_putchar_locked(struct uart_port *port, int ch)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
@@ -3316,6 +3309,18 @@ static void serial8250_console_putchar(struct uart_port *port, int ch)
 	serial_port_out(port, UART_TX, ch);
 }
 
+static void serial8250_console_putchar(struct uart_port *port, int ch)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	wait_for_xmitr(up, UART_LSR_THRE);
+
+	console_atomic_lock(flags);
+	serial8250_console_putchar_locked(port, ch);
+	console_atomic_unlock(flags);
+}
+
 /*
  *	Restore serial console when h/w power-off detected
  */
@@ -3342,6 +3347,32 @@ static void serial8250_console_restore(struct uart_8250_port *up)
 	serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS);
 }
 
+void serial8250_console_write_atomic(struct uart_8250_port *up,
+				     const char *s, unsigned int count)
+{
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int ier;
+
+	console_atomic_lock(flags);
+
+	touch_nmi_watchdog();
+
+	ier = serial8250_clear_IER(up);
+
+	if (atomic_fetch_inc(&up->console_printing)) {
+		uart_console_write(port, "\n", 1,
+				   serial8250_console_putchar_locked);
+	}
+	uart_console_write(port, s, count, serial8250_console_putchar_locked);
+	atomic_dec(&up->console_printing);
+
+	wait_for_xmitr(up, BOTH_EMPTY);
+	serial8250_set_IER(up, ier);
+
+	console_atomic_unlock(flags);
+}
+
 /*
  *	Print a string to the serial port trying not to disturb
  *	any possible real use of the port...
@@ -3358,24 +3389,12 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 	struct uart_port *port = &up->port;
 	unsigned long flags;
 	unsigned int ier;
-	int locked = 1;
 
 	touch_nmi_watchdog();
 
-	if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
-	else
-		spin_lock_irqsave(&port->lock, flags);
-
-	/*
-	 *	First save the IER then disable the interrupts
-	 */
-	ier = serial_port_in(port, UART_IER);
+	spin_lock_irqsave(&port->lock, flags);
 
-	if (up->capabilities & UART_CAP_UUE)
-		serial_port_out(port, UART_IER, UART_IER_UUE);
-	else
-		serial_port_out(port, UART_IER, 0);
+	ier = serial8250_clear_IER(up);
 
 	/* check scratch reg to see if port powered off during system sleep */
 	if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
@@ -3389,7 +3408,9 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 		mdelay(port->rs485.delay_rts_before_send);
 	}
 
+	atomic_inc(&up->console_printing);
 	uart_console_write(port, s, count, serial8250_console_putchar);
+	atomic_dec(&up->console_printing);
 
 	/*
 	 *	Finally, wait for transmitter to become empty
@@ -3402,8 +3423,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 		if (em485->tx_stopped)
 			up->rs485_stop_tx(up);
 	}
-
-	serial_port_out(port, UART_IER, ier);
+	serial8250_set_IER(up, ier);
 
 	/*
 	 *	The receive handling will happen properly because the
@@ -3415,8 +3435,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 	if (up->msr_saved_flags)
 		serial8250_modem_status(up);
 
-	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+	spin_unlock_irqrestore(&port->lock, flags);
 }
 
 static unsigned int probe_baud(struct uart_port *port)
@@ -3436,6 +3455,7 @@ static unsigned int probe_baud(struct uart_port *port)
 
 int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
 {
+	struct uart_8250_port *up = up_to_u8250p(port);
 	int baud = 9600;
 	int bits = 8;
 	int parity = 'n';
@@ -3445,6 +3465,8 @@ int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
 	if (!port->iobase && !port->membase)
 		return -ENODEV;
 
+	atomic_set(&up->console_printing, 0);
+
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
 	else if (probe)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index c881d4413b899..928d4620e8bfa 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2343,7 +2343,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
 {
 	struct uart_amba_port *uap = amba_ports[co->index];
 	unsigned int old_cr = 0, new_cr;
-	unsigned long flags;
+	unsigned long flags = 0;
 	int locked = 1;
 
 	clk_enable(uap->clk);
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 0862941862c8b..10970632f0e47 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1255,13 +1255,10 @@ serial_omap_console_write(struct console *co, const char *s,
 	unsigned int ier;
 	int locked = 1;
 
-	local_irq_save(flags);
-	if (up->port.sysrq)
-		locked = 0;
-	else if (oops_in_progress)
-		locked = spin_trylock(&up->port.lock);
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
 	else
-		spin_lock(&up->port.lock);
+		spin_lock_irqsave(&up->port.lock, flags);
 
 	/*
 	 * First save the IER then disable the interrupts
@@ -1288,8 +1285,7 @@ serial_omap_console_write(struct console *co, const char *s,
 		check_modem_status(up);
 
 	if (locked)
-		spin_unlock(&up->port.lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static int __init
diff --git a/drivers/virt/acrn/irqfd.c b/drivers/virt/acrn/irqfd.c
index df5184979b282..d4ad211dce7a3 100644
--- a/drivers/virt/acrn/irqfd.c
+++ b/drivers/virt/acrn/irqfd.c
@@ -17,7 +17,6 @@
 #include "acrn_drv.h"
 
 static LIST_HEAD(acrn_irqfd_clients);
-static DEFINE_MUTEX(acrn_irqfds_mutex);
 
 /**
  * struct hsm_irqfd - Properties of HSM irqfd
diff --git a/fs/afs/dir_silly.c b/fs/afs/dir_silly.c
index 45cfd50a95210..502b56597f107 100644
--- a/fs/afs/dir_silly.c
+++ b/fs/afs/dir_silly.c
@@ -239,7 +239,7 @@ int afs_silly_iput(struct dentry *dentry, struct inode *inode)
 	struct dentry *alias;
 	int ret;
 
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	_enter("%p{%pd},%llx", dentry, dentry, vnode->fid.vnode);
 
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 7c47a03afbcc3..ed0fd86ba227b 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -69,7 +69,7 @@ cifs_prime_dcache(struct dentry *parent, struct qstr *name,
 	struct inode *inode;
 	struct super_block *sb = parent->d_sb;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 54208fcef3389..3fe70597a1a1a 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2546,7 +2546,13 @@ EXPORT_SYMBOL(d_rehash);
 
 static inline unsigned start_dir_add(struct inode *dir)
 {
-
+	/*
+	 * The caller has a spinlock_t (dentry::d_lock) acquired which disables
+	 * preemption on !PREEMPT_RT. On PREEMPT_RT the lock does not disable
+	 * preemption and it has be done explicitly.
+	 */
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_disable();
 	for (;;) {
 		unsigned n = dir->i_dir_seq;
 		if (!(n & 1) && cmpxchg(&dir->i_dir_seq, n, n + 1) == n)
@@ -2558,25 +2564,30 @@ static inline unsigned start_dir_add(struct inode *dir)
 static inline void end_dir_add(struct inode *dir, unsigned n)
 {
 	smp_store_release(&dir->i_dir_seq, n + 2);
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_enable();
 }
 
 static void d_wait_lookup(struct dentry *dentry)
 {
-	if (d_in_lookup(dentry)) {
-		DECLARE_WAITQUEUE(wait, current);
-		add_wait_queue(dentry->d_wait, &wait);
-		do {
-			set_current_state(TASK_UNINTERRUPTIBLE);
-			spin_unlock(&dentry->d_lock);
-			schedule();
-			spin_lock(&dentry->d_lock);
-		} while (d_in_lookup(dentry));
-	}
+	struct swait_queue __wait;
+
+	if (!d_in_lookup(dentry))
+		return;
+
+	INIT_LIST_HEAD(&__wait.task_list);
+	do {
+		prepare_to_swait_exclusive(dentry->d_wait, &__wait, TASK_UNINTERRUPTIBLE);
+		spin_unlock(&dentry->d_lock);
+		schedule();
+		spin_lock(&dentry->d_lock);
+	} while (d_in_lookup(dentry));
+	finish_swait(dentry->d_wait, &__wait);
 }
 
 struct dentry *d_alloc_parallel(struct dentry *parent,
 				const struct qstr *name,
-				wait_queue_head_t *wq)
+				struct swait_queue_head *wq)
 {
 	unsigned int hash = name->hash;
 	struct hlist_bl_head *b = in_lookup_hash(parent, hash);
@@ -2691,7 +2702,7 @@ void __d_lookup_done(struct dentry *dentry)
 	hlist_bl_lock(b);
 	dentry->d_flags &= ~DCACHE_PAR_LOOKUP;
 	__hlist_bl_del(&dentry->d_u.d_in_lookup_hash);
-	wake_up_all(dentry->d_wait);
+	swake_up_all(dentry->d_wait);
 	dentry->d_wait = NULL;
 	hlist_bl_unlock(b);
 	INIT_HLIST_NODE(&dentry->d_u.d_alias);
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index c3e4804b8fcbf..9edb87e11680b 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -81,7 +81,6 @@ extern unsigned fscache_debug;
 extern struct kobject *fscache_root;
 extern struct workqueue_struct *fscache_object_wq;
 extern struct workqueue_struct *fscache_op_wq;
-DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
 
 extern unsigned int fscache_hash(unsigned int salt, unsigned int *data, unsigned int n);
 
diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index 4207f98e405fd..85f8cf3a323d5 100644
--- a/fs/fscache/main.c
+++ b/fs/fscache/main.c
@@ -41,8 +41,6 @@ struct kobject *fscache_root;
 struct workqueue_struct *fscache_object_wq;
 struct workqueue_struct *fscache_op_wq;
 
-DEFINE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
-
 /* these values serve as lower bounds, will be adjusted in fscache_init() */
 static unsigned fscache_object_max_active = 4;
 static unsigned fscache_op_max_active = 2;
@@ -138,7 +136,6 @@ unsigned int fscache_hash(unsigned int salt, unsigned int *data, unsigned int n)
 static int __init fscache_init(void)
 {
 	unsigned int nr_cpus = num_possible_cpus();
-	unsigned int cpu;
 	int ret;
 
 	fscache_object_max_active =
@@ -161,9 +158,6 @@ static int __init fscache_init(void)
 	if (!fscache_op_wq)
 		goto error_op_wq;
 
-	for_each_possible_cpu(cpu)
-		init_waitqueue_head(&per_cpu(fscache_object_cong_wait, cpu));
-
 	ret = fscache_proc_init();
 	if (ret < 0)
 		goto error_proc;
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 6a675652129b2..7a972d144b546 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -798,6 +798,8 @@ void fscache_object_destroy(struct fscache_object *object)
 }
 EXPORT_SYMBOL(fscache_object_destroy);
 
+static DECLARE_WAIT_QUEUE_HEAD(fscache_object_cong_wait);
+
 /*
  * enqueue an object for metadata-type processing
  */
@@ -806,16 +808,12 @@ void fscache_enqueue_object(struct fscache_object *object)
 	_enter("{OBJ%x}", object->debug_id);
 
 	if (fscache_get_object(object, fscache_obj_get_queue) >= 0) {
-		wait_queue_head_t *cong_wq =
-			&get_cpu_var(fscache_object_cong_wait);
 
 		if (queue_work(fscache_object_wq, &object->work)) {
 			if (fscache_object_congested())
-				wake_up(cong_wq);
+				wake_up(&fscache_object_cong_wait);
 		} else
 			fscache_put_object(object, fscache_obj_put_queue);
-
-		put_cpu_var(fscache_object_cong_wait);
 	}
 }
 
@@ -833,16 +831,15 @@ void fscache_enqueue_object(struct fscache_object *object)
  */
 bool fscache_object_sleep_till_congested(signed long *timeoutp)
 {
-	wait_queue_head_t *cong_wq = this_cpu_ptr(&fscache_object_cong_wait);
 	DEFINE_WAIT(wait);
 
 	if (fscache_object_congested())
 		return true;
 
-	add_wait_queue_exclusive(cong_wq, &wait);
+	add_wait_queue_exclusive(&fscache_object_cong_wait, &wait);
 	if (!fscache_object_congested())
 		*timeoutp = schedule_timeout(*timeoutp);
-	finish_wait(cong_wq, &wait);
+	finish_wait(&fscache_object_cong_wait, &wait);
 
 	return fscache_object_congested();
 }
diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c
index 0e4a2681515ff..be9c04edbb7a8 100644
--- a/fs/fuse/readdir.c
+++ b/fs/fuse/readdir.c
@@ -164,7 +164,7 @@ static int fuse_direntplus_link(struct file *file,
 	struct inode *dir = d_inode(parent);
 	struct fuse_conn *fc;
 	struct inode *inode;
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	if (!o->nodeid) {
 		/*
diff --git a/fs/namei.c b/fs/namei.c
index 5cc5b3e984628..9e4d4db71fc3c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1647,7 +1647,7 @@ static struct dentry *__lookup_slow(const struct qstr *name,
 {
 	struct dentry *dentry, *old;
 	struct inode *inode = dir->d_inode;
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	/* Don't go there if it's already dead */
 	if (unlikely(IS_DEADDIR(inode)))
@@ -3383,7 +3383,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 	struct dentry *dentry;
 	int error, create_error = 0;
 	umode_t mode = op->mode;
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	if (unlikely(IS_DEADDIR(dir_inode)))
 		return ERR_PTR(-ENOENT);
diff --git a/fs/namespace.c b/fs/namespace.c
index 2c502d554f619..fddfe08beeaf8 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -353,8 +353,24 @@ int __mnt_want_write(struct vfsmount *m)
 	 * incremented count after it has set MNT_WRITE_HOLD.
 	 */
 	smp_mb();
-	while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD)
-		cpu_relax();
+	might_lock(&mount_lock.lock);
+	while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) {
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			cpu_relax();
+		} else {
+			/*
+			 * This prevents priority inversion, if the task
+			 * setting MNT_WRITE_HOLD got preempted on a remote
+			 * CPU, and it prevents life lock if the task setting
+			 * MNT_WRITE_HOLD has a lower priority and is bound to
+			 * the same CPU as the task that is spinning here.
+			 */
+			preempt_enable();
+			lock_mount_hash();
+			unlock_mount_hash();
+			preempt_disable();
+		}
+	}
 	/*
 	 * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
 	 * be set to match its requirements. So we must not load that until
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index dd0b7488e9ccb..322404743bb4e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -637,7 +637,7 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry,
 		unsigned long dir_verifier)
 {
 	struct qstr filename = QSTR_INIT(entry->name, entry->len);
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 	struct dentry *dentry;
 	struct dentry *alias;
 	struct inode *inode;
@@ -1905,7 +1905,7 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
 		    struct file *file, unsigned open_flags,
 		    umode_t mode)
 {
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 	struct nfs_open_context *ctx;
 	struct dentry *res;
 	struct iattr attr = { .ia_valid = ATTR_OPEN };
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index d5ccf095b2a7d..0944c068f5cb9 100644
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -13,7 +13,7 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/nfs_fs.h>
 #include <linux/sched.h>
-#include <linux/wait.h>
+#include <linux/swait.h>
 #include <linux/namei.h>
 #include <linux/fsnotify.h>
 
@@ -184,7 +184,7 @@ nfs_async_unlink(struct dentry *dentry, const struct qstr *name)
 
 	data->cred = get_current_cred();
 	data->res.dir_attr = &data->dir_attr;
-	init_waitqueue_head(&data->wq);
+	init_swait_queue_head(&data->wq);
 
 	status = -EBUSY;
 	spin_lock(&dentry->d_lock);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index b0b99219a2ad0..2a2d2b34a641e 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -97,6 +97,7 @@
 #include <linux/posix-timers.h>
 #include <linux/time_namespace.h>
 #include <linux/resctrl.h>
+#include <linux/swait.h>
 #include <linux/cn_proc.h>
 #include <trace/events/oom.h>
 #include "internal.h"
@@ -2116,7 +2117,7 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx,
 
 	child = d_hash_and_lookup(dir, &qname);
 	if (!child) {
-		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+		DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 		child = d_alloc_parallel(dir, &qname, &wq);
 		if (IS_ERR(child))
 			goto end_instantiate;
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 1a22aa43e740d..0d8a117a4bd87 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -680,7 +680,7 @@ static bool proc_sys_fill_cache(struct file *file,
 
 	child = d_lookup(dir, &qname);
 	if (!child) {
-		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+		DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 		child = d_alloc_parallel(dir, &qname, &wq);
 		if (IS_ERR(child))
 			return false;
diff --git a/include/asm-generic/softirq_stack.h b/include/asm-generic/softirq_stack.h
index eceeecf6a5bd8..d3e2d81656e04 100644
--- a/include/asm-generic/softirq_stack.h
+++ b/include/asm-generic/softirq_stack.h
@@ -2,7 +2,7 @@
 #ifndef __ASM_GENERIC_SOFTIRQ_STACK_H
 #define __ASM_GENERIC_SOFTIRQ_STACK_H
 
-#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
+#if defined(CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK) && !defined(CONFIG_PREEMPT_RT)
 void do_softirq_own_stack(void);
 #else
 static inline void do_softirq_own_stack(void)
diff --git a/include/linux/console.h b/include/linux/console.h
index e2862542a162d..078cc8ef084f3 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -16,6 +16,13 @@
 
 #include <linux/atomic.h>
 #include <linux/types.h>
+#include <linux/printk.h>
+#include <linux/seqlock.h>
+
+struct latched_seq {
+	seqcount_latch_t	latch;
+	u64			val[2];
+};
 
 struct vc_data;
 struct console_font_op;
@@ -141,10 +148,12 @@ static inline int con_debug_leave(void)
 #define CON_ANYTIME	(16) /* Safe to call when cpu is offline */
 #define CON_BRL		(32) /* Used for a braille device */
 #define CON_EXTENDED	(64) /* Use the extended output format a la /dev/kmsg */
+#define CON_HANDOVER	(128) /* Device was previously a boot console. */
 
 struct console {
 	char	name[16];
 	void	(*write)(struct console *, const char *, unsigned);
+	void	(*write_atomic)(struct console *co, const char *s, unsigned int count);
 	int	(*read)(struct console *, char *, unsigned);
 	struct tty_driver *(*device)(struct console *, int *);
 	void	(*unblank)(void);
@@ -154,6 +163,16 @@ struct console {
 	short	flags;
 	short	index;
 	int	cflag;
+#ifdef CONFIG_PRINTK
+	char	sync_buf[CONSOLE_LOG_MAX];
+	struct latched_seq printk_seq;
+	struct latched_seq printk_sync_seq;
+#ifdef CONFIG_HAVE_NMI
+	struct latched_seq printk_sync_nmi_seq;
+#endif
+#endif /* CONFIG_PRINTK */
+
+	struct task_struct *thread;
 	uint	ispeed;
 	uint	ospeed;
 	void	*data;
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 9e23d33bb6f1c..9f89d4887e35d 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -108,7 +108,7 @@ struct dentry {
 
 	union {
 		struct list_head d_lru;		/* LRU list */
-		wait_queue_head_t *d_wait;	/* in-lookup ones only */
+		struct swait_queue_head *d_wait;	/* in-lookup ones only */
 	};
 	struct list_head d_child;	/* child of parent list */
 	struct list_head d_subdirs;	/* our children */
@@ -240,7 +240,7 @@ extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op
 extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
 extern struct dentry * d_alloc_anon(struct super_block *);
 extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *,
-					wait_queue_head_t *);
+					struct swait_queue_head *);
 extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
 extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
 extern struct dentry * d_exact_alias(struct dentry *, struct inode *);
diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
index 2e2b8d6140ed4..71064a2c2cafe 100644
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -57,9 +57,15 @@
 # define ARCH_EXIT_TO_USER_MODE_WORK		(0)
 #endif
 
+#ifdef CONFIG_PREEMPT_LAZY
+# define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
+#else
+# define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED)
+#endif
+
 #define EXIT_TO_USER_MODE_WORK						\
 	(_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_UPROBE |		\
-	 _TIF_NEED_RESCHED | _TIF_PATCH_PENDING | _TIF_NOTIFY_SIGNAL |	\
+	 _TIF_NEED_RESCHED_MASK | _TIF_PATCH_PENDING | _TIF_NOTIFY_SIGNAL |	\
 	 ARCH_EXIT_TO_USER_MODE_WORK)
 
 /**
diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index e9743cfd85852..b0f196e51dcac 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -69,7 +69,10 @@ io_mapping_map_atomic_wc(struct io_mapping *mapping,
 
 	BUG_ON(offset >= mapping->size);
 	phys_addr = mapping->base + offset;
-	preempt_disable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_disable();
+	else
+		migrate_disable();
 	pagefault_disable();
 	return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
 }
@@ -79,7 +82,10 @@ io_mapping_unmap_atomic(void __iomem *vaddr)
 {
 	kunmap_local_indexed((void __force *)vaddr);
 	pagefault_enable();
-	preempt_enable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_enable();
+	else
+		migrate_enable();
 }
 
 static inline void __iomem *
@@ -168,7 +174,10 @@ static inline void __iomem *
 io_mapping_map_atomic_wc(struct io_mapping *mapping,
 			 unsigned long offset)
 {
-	preempt_disable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_disable();
+	else
+		migrate_disable();
 	pagefault_disable();
 	return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
 }
@@ -178,7 +187,10 @@ io_mapping_unmap_atomic(void __iomem *vaddr)
 {
 	io_mapping_unmap(vaddr);
 	pagefault_enable();
-	preempt_enable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		preempt_enable();
+	else
+		migrate_enable();
 }
 
 static inline void __iomem *
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index ee5f9120c4d73..136f2980cba30 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -3,6 +3,7 @@
 #define _LINUX_IRQ_WORK_H
 
 #include <linux/smp_types.h>
+#include <linux/rcuwait.h>
 
 /*
  * An entry can be in one of four states:
@@ -16,11 +17,13 @@
 struct irq_work {
 	struct __call_single_node node;
 	void (*func)(struct irq_work *);
+	struct rcuwait irqwait;
 };
 
 #define __IRQ_WORK_INIT(_func, _flags) (struct irq_work){	\
 	.node = { .u_flags = (_flags), },			\
 	.func = (_func),					\
+	.irqwait = __RCUWAIT_INITIALIZER(irqwait),		\
 }
 
 #define IRQ_WORK_INIT(_func) __IRQ_WORK_INIT(_func, 0)
@@ -46,6 +49,11 @@ static inline bool irq_work_is_busy(struct irq_work *work)
 	return atomic_read(&work->node.a_flags) & IRQ_WORK_BUSY;
 }
 
+static inline bool irq_work_is_hard(struct irq_work *work)
+{
+	return atomic_read(&work->node.a_flags) & IRQ_WORK_HARD_IRQ;
+}
+
 bool irq_work_queue(struct irq_work *work);
 bool irq_work_queue_on(struct irq_work *work, int cpu);
 
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 59aea39785bfd..d69b819b53e01 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -160,6 +160,7 @@ static inline void generic_handle_irq_desc(struct irq_desc *desc)
 
 int handle_irq_desc(struct irq_desc *desc);
 int generic_handle_irq(unsigned int irq);
+int generic_handle_irq_safe(unsigned int irq);
 
 #ifdef CONFIG_IRQ_DOMAIN
 /*
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index c4288c7ae613f..2e09c269bf9d8 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -72,14 +72,6 @@ do {						\
 do {						\
 	__this_cpu_dec(hardirq_context);	\
 } while (0)
-# define lockdep_softirq_enter()		\
-do {						\
-	current->softirq_context++;		\
-} while (0)
-# define lockdep_softirq_exit()			\
-do {						\
-	current->softirq_context--;		\
-} while (0)
 
 # define lockdep_hrtimer_enter(__hrtimer)		\
 ({							\
@@ -141,6 +133,21 @@ do {						\
 # define lockdep_irq_work_exit(__work)		do { } while (0)
 #endif
 
+#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT)
+# define lockdep_softirq_enter()		\
+do {						\
+	current->softirq_context++;		\
+} while (0)
+# define lockdep_softirq_exit()			\
+do {						\
+	current->softirq_context--;		\
+} while (0)
+
+#else
+# define lockdep_softirq_enter()		do { } while (0)
+# define lockdep_softirq_exit()			do { } while (0)
+#endif
+
 #if defined(CONFIG_IRQSOFF_TRACER) || \
 	defined(CONFIG_PREEMPT_TRACER)
  extern void stop_critical_timings(void);
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 5717a0965bd6c..009e6af7e9adb 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -106,8 +106,8 @@ static __always_inline void might_resched(void)
 #endif /* CONFIG_PREEMPT_* */
 
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
-extern void ___might_sleep(const char *file, int line, int preempt_offset);
-extern void __might_sleep(const char *file, int line, int preempt_offset);
+extern void __might_resched(const char *file, int line, unsigned int offsets);
+extern void __might_sleep(const char *file, int line);
 extern void __cant_sleep(const char *file, int line, int preempt_offset);
 extern void __cant_migrate(const char *file, int line);
 
@@ -124,7 +124,7 @@ extern void __cant_migrate(const char *file, int line);
  * supposed to.
  */
 # define might_sleep() \
-	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
+	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 /**
  * cant_sleep - annotation for functions that cannot sleep
  *
@@ -163,10 +163,9 @@ extern void __cant_migrate(const char *file, int line);
  */
 # define non_block_end() WARN_ON(current->non_block_count-- == 0)
 #else
-  static inline void ___might_sleep(const char *file, int line,
-				   int preempt_offset) { }
-  static inline void __might_sleep(const char *file, int line,
-				   int preempt_offset) { }
+  static inline void __might_resched(const char *file, int line,
+				     unsigned int offsets) { }
+static inline void __might_sleep(const char *file, int line) { }
 # define might_sleep() do { might_resched(); } while (0)
 # define cant_sleep() do { } while (0)
 # define cant_migrate()		do { } while (0)
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 258cdde8d356b..9bca0d98db5a1 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -212,6 +212,8 @@ extern void kgdb_call_nmi_hook(void *ignored);
  */
 extern void kgdb_roundup_cpus(void);
 
+extern void kgdb_roundup_cpu(unsigned int cpu);
+
 /**
  *	kgdb_arch_set_pc - Generic call back to the program counter
  *	@regs: Current &struct pt_regs.
@@ -365,5 +367,6 @@ extern void kgdb_free_init_mem(void);
 #define dbg_late_init()
 static inline void kgdb_panic(const char *msg) {}
 static inline void kgdb_free_init_mem(void) { }
+static inline void kgdb_roundup_cpu(unsigned int cpu) {}
 #endif /* ! CONFIG_KGDB */
 #endif /* _KGDB_H_ */
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index c6a06273f69a8..e791cdbaa0e3f 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -340,6 +340,16 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
 
+/*
+ * Must use lock_map_aquire_try() with override maps to avoid
+ * lockdep thinking they participate in the block chain.
+ */
+#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type)	\
+	struct lockdep_map _name = {			\
+		.name = #_name "-wait-type-override",	\
+		.wait_type_inner = _wait_type,		\
+		.lock_type = LD_LOCK_WAIT_OVERRIDE, }
+
 #else /* !CONFIG_LOCKDEP */
 
 static inline void lockdep_init_task(struct task_struct *task)
@@ -427,6 +437,9 @@ extern int lockdep_is_held(const void *);
 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
 
+#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type)	\
+	struct lockdep_map __maybe_unused _name = {}
+
 #endif /* !LOCKDEP */
 
 enum xhlock_context_t {
@@ -569,6 +582,7 @@ do {									\
 #define rwsem_release(l, i)			lock_release(l, i)
 
 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
+#define lock_map_acquire_try(l)			lock_acquire_exclusive(l, 0, 1, NULL, _THIS_IP_)
 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
 #define lock_map_release(l)			lock_release(l, _THIS_IP_)
diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h
index 3e726ace5c621..a5f1519489df6 100644
--- a/include/linux/lockdep_types.h
+++ b/include/linux/lockdep_types.h
@@ -33,6 +33,7 @@ enum lockdep_wait_type {
 enum lockdep_lock_type {
 	LD_LOCK_NORMAL = 0,	/* normal, catch all */
 	LD_LOCK_PERCPU,		/* percpu */
+	LD_LOCK_WAIT_OVERRIDE,	/* annotation */
 	LD_LOCK_MAX,
 };
 
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 07285b44d831a..172889241f049 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -12,6 +12,7 @@
 #include <linux/completion.h>
 #include <linux/cpumask.h>
 #include <linux/uprobes.h>
+#include <linux/rcupdate.h>
 #include <linux/page-flags-layout.h>
 #include <linux/workqueue.h>
 #include <linux/seqlock.h>
@@ -575,6 +576,9 @@ struct mm_struct {
 		bool tlb_flush_batched;
 #endif
 		struct uprobes_state uprobes_state;
+#ifdef CONFIG_PREEMPT_RT
+		struct rcu_head delayed_drop;
+#endif
 #ifdef CONFIG_HUGETLB_PAGE
 		atomic_long_t hugetlb_usage;
 #endif
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ae79df28174e1..67c081c211b7e 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1950,7 +1950,6 @@ enum netdev_ml_priv_type {
  *	@sfp_bus:	attached &struct sfp_bus structure.
  *
  *	@qdisc_tx_busylock: lockdep class annotating Qdisc->busylock spinlock
- *	@qdisc_running_key: lockdep class annotating Qdisc->running seqcount
  *
  *	@proto_down:	protocol port state information can be sent to the
  *			switch driver and used to set the phys state of the
@@ -2281,7 +2280,6 @@ struct net_device {
 	struct phy_device	*phydev;
 	struct sfp_bus		*sfp_bus;
 	struct lock_class_key	*qdisc_tx_busylock;
-	struct lock_class_key	*qdisc_running_key;
 	bool			proto_down;
 	unsigned		wol_enabled:1;
 	unsigned		threaded:1;
@@ -2391,13 +2389,11 @@ static inline void netdev_for_each_tx_queue(struct net_device *dev,
 #define netdev_lockdep_set_classes(dev)				\
 {								\
 	static struct lock_class_key qdisc_tx_busylock_key;	\
-	static struct lock_class_key qdisc_running_key;		\
 	static struct lock_class_key qdisc_xmit_lock_key;	\
 	static struct lock_class_key dev_addr_list_lock_key;	\
 	unsigned int i;						\
 								\
 	(dev)->qdisc_tx_busylock = &qdisc_tx_busylock_key;	\
-	(dev)->qdisc_running_key = &qdisc_running_key;		\
 	lockdep_set_class(&(dev)->addr_list_lock,		\
 			  &dev_addr_list_lock_key);		\
 	for (i = 0; i < (dev)->num_tx_queues; i++)		\
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 7321a5a95087f..03c598c351c7a 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1694,7 +1694,7 @@ struct nfs_unlinkdata {
 	struct nfs_removeargs args;
 	struct nfs_removeres res;
 	struct dentry *dentry;
-	wait_queue_head_t wq;
+	struct swait_queue_head wq;
 	const struct cred *cred;
 	struct nfs_fattr dir_attr;
 	long timeout;
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 436f030a93f37..29b86c7785f00 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -155,9 +155,10 @@ static __always_inline unsigned char interrupt_context_level(void)
  * The preempt_count offset after spin_lock()
  */
 #if !defined(CONFIG_PREEMPT_RT)
-#define PREEMPT_LOCK_OFFSET	PREEMPT_DISABLE_OFFSET
+#define PREEMPT_LOCK_OFFSET		PREEMPT_DISABLE_OFFSET
 #else
-#define PREEMPT_LOCK_OFFSET	0
+/* Locks on RT do not disable preemption */
+#define PREEMPT_LOCK_OFFSET		0
 #endif
 
 /*
@@ -207,6 +208,20 @@ extern void preempt_count_sub(int val);
 #define preempt_count_inc() preempt_count_add(1)
 #define preempt_count_dec() preempt_count_sub(1)
 
+#ifdef CONFIG_PREEMPT_LAZY
+#define add_preempt_lazy_count(val)	do { preempt_lazy_count() += (val); } while (0)
+#define sub_preempt_lazy_count(val)	do { preempt_lazy_count() -= (val); } while (0)
+#define inc_preempt_lazy_count()	add_preempt_lazy_count(1)
+#define dec_preempt_lazy_count()	sub_preempt_lazy_count(1)
+#define preempt_lazy_count()		(current_thread_info()->preempt_lazy_count)
+#else
+#define add_preempt_lazy_count(val)	do { } while (0)
+#define sub_preempt_lazy_count(val)	do { } while (0)
+#define inc_preempt_lazy_count()	do { } while (0)
+#define dec_preempt_lazy_count()	do { } while (0)
+#define preempt_lazy_count()		(0)
+#endif
+
 #ifdef CONFIG_PREEMPT_COUNT
 
 #define preempt_disable() \
@@ -215,13 +230,25 @@ do { \
 	barrier(); \
 } while (0)
 
+#define preempt_lazy_disable() \
+do { \
+	inc_preempt_lazy_count(); \
+	barrier(); \
+} while (0)
+
 #define sched_preempt_enable_no_resched() \
 do { \
 	barrier(); \
 	preempt_count_dec(); \
 } while (0)
 
-#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+#ifndef CONFIG_PREEMPT_RT
+# define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+# define preempt_check_resched_rt() barrier();
+#else
+# define preempt_enable_no_resched() preempt_enable()
+# define preempt_check_resched_rt() preempt_check_resched()
+#endif
 
 #define preemptible()	(preempt_count() == 0 && !irqs_disabled())
 
@@ -246,6 +273,18 @@ do { \
 		__preempt_schedule(); \
 } while (0)
 
+/*
+ * open code preempt_check_resched() because it is not exported to modules and
+ * used by local_unlock() or bpf_enable_instrumentation().
+ */
+#define preempt_lazy_enable() \
+do { \
+	dec_preempt_lazy_count(); \
+	barrier(); \
+	if (should_resched(0)) \
+		__preempt_schedule(); \
+} while (0)
+
 #else /* !CONFIG_PREEMPTION */
 #define preempt_enable() \
 do { \
@@ -253,6 +292,12 @@ do { \
 	preempt_count_dec(); \
 } while (0)
 
+#define preempt_lazy_enable() \
+do { \
+	dec_preempt_lazy_count(); \
+	barrier(); \
+} while (0)
+
 #define preempt_enable_notrace() \
 do { \
 	barrier(); \
@@ -291,8 +336,12 @@ do { \
 #define preempt_disable_notrace()		barrier()
 #define preempt_enable_no_resched_notrace()	barrier()
 #define preempt_enable_notrace()		barrier()
+#define preempt_check_resched_rt()		barrier()
 #define preemptible()				0
 
+#define preempt_lazy_disable()			barrier()
+#define preempt_lazy_enable()			barrier()
+
 #endif /* CONFIG_PREEMPT_COUNT */
 
 #ifdef MODULE
@@ -311,7 +360,7 @@ do { \
 } while (0)
 #define preempt_fold_need_resched() \
 do { \
-	if (tif_need_resched()) \
+	if (tif_need_resched_now()) \
 		set_preempt_need_resched(); \
 } while (0)
 
@@ -427,8 +476,15 @@ extern void migrate_enable(void);
 
 #else
 
-static inline void migrate_disable(void) { }
-static inline void migrate_enable(void) { }
+static inline void migrate_disable(void)
+{
+	preempt_lazy_disable();
+}
+
+static inline void migrate_enable(void)
+{
+	preempt_lazy_enable();
+}
 
 #endif /* CONFIG_SMP */
 
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 05a1bd8aa6bb4..b083e3796c166 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -47,6 +47,12 @@ static inline const char *printk_skip_headers(const char *buffer)
 
 #define CONSOLE_EXT_LOG_MAX	8192
 
+/*
+ * The maximum size of a record formatted for console printing
+ * (i.e. with the prefix prepended to every line).
+ */
+#define CONSOLE_LOG_MAX		1024
+
 /* printk's without a loglevel use this.. */
 #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
 
@@ -155,6 +161,8 @@ int vprintk(const char *fmt, va_list args);
 asmlinkage __printf(1, 2) __cold
 int _printk(const char *fmt, ...);
 
+bool pr_flush(int timeout_ms, bool reset_on_progress);
+
 /*
  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
  */
@@ -224,6 +232,11 @@ static inline void printk_deferred_exit(void)
 {
 }
 
+static inline bool pr_flush(int timeout_ms, bool reset_on_progress)
+{
+	return true;
+}
+
 static inline int printk_ratelimit(void)
 {
 	return 0;
@@ -284,17 +297,30 @@ static inline void printk_trigger_flush(void)
 extern int __printk_cpu_trylock(void);
 extern void __printk_wait_on_cpu_lock(void);
 extern void __printk_cpu_unlock(void);
+extern bool kgdb_roundup_delay(unsigned int cpu);
+
+#else
+
+#define __printk_cpu_trylock()		1
+#define __printk_wait_on_cpu_lock()
+#define __printk_cpu_unlock()
+
+static inline bool kgdb_roundup_delay(unsigned int cpu)
+{
+	return false;
+}
+#endif /* CONFIG_SMP */
 
 /**
- * printk_cpu_lock_irqsave() - Acquire the printk cpu-reentrant spinning
- *                             lock and disable interrupts.
+ * raw_printk_cpu_lock_irqsave() - Acquire the printk cpu-reentrant spinning
+ *                                 lock and disable interrupts.
  * @flags: Stack-allocated storage for saving local interrupt state,
- *         to be passed to printk_cpu_unlock_irqrestore().
+ *         to be passed to raw_printk_cpu_unlock_irqrestore().
  *
  * If the lock is owned by another CPU, spin until it becomes available.
  * Interrupts are restored while spinning.
  */
-#define printk_cpu_lock_irqsave(flags)		\
+#define raw_printk_cpu_lock_irqsave(flags)	\
 	for (;;) {				\
 		local_irq_save(flags);		\
 		if (__printk_cpu_trylock())	\
@@ -304,22 +330,30 @@ extern void __printk_cpu_unlock(void);
 	}
 
 /**
- * printk_cpu_unlock_irqrestore() - Release the printk cpu-reentrant spinning
- *                                  lock and restore interrupts.
- * @flags: Caller's saved interrupt state, from printk_cpu_lock_irqsave().
+ * raw_printk_cpu_unlock_irqrestore() - Release the printk cpu-reentrant
+ *                                      spinning lock and restore interrupts.
+ * @flags: Caller's saved interrupt state from raw_printk_cpu_lock_irqsave().
  */
-#define printk_cpu_unlock_irqrestore(flags)	\
+#define raw_printk_cpu_unlock_irqrestore(flags)	\
 	do {					\
 		__printk_cpu_unlock();		\
 		local_irq_restore(flags);	\
-	} while (0)				\
-
-#else
+	} while (0)
 
-#define printk_cpu_lock_irqsave(flags) ((void)flags)
-#define printk_cpu_unlock_irqrestore(flags) ((void)flags)
+/*
+ * Used to synchronize atomic consoles.
+ *
+ * The same as raw_printk_cpu_lock_irqsave() except that hardware interrupts
+ * are _not_ restored while spinning.
+ */
+#define console_atomic_lock(flags)		\
+	do {					\
+		local_irq_save(flags);		\
+		while (!__printk_cpu_trylock())	\
+			cpu_relax();		\
+	} while (0)
 
-#endif /* CONFIG_SMP */
+#define console_atomic_unlock raw_printk_cpu_unlock_irqrestore
 
 extern int kptr_restrict;
 
diff --git a/include/linux/ratelimit_types.h b/include/linux/ratelimit_types.h
index f0e535f199bef..002266693e506 100644
--- a/include/linux/ratelimit_types.h
+++ b/include/linux/ratelimit_types.h
@@ -4,7 +4,7 @@
 
 #include <linux/bits.h>
 #include <linux/param.h>
-#include <linux/spinlock_types.h>
+#include <linux/spinlock_types_raw.h>
 
 #define DEFAULT_RATELIMIT_INTERVAL	(5 * HZ)
 #define DEFAULT_RATELIMIT_BURST		10
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 552216218d734..1026d14e3a2f1 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -95,6 +95,13 @@ void rcu_init_tasks_generic(void);
 static inline void rcu_init_tasks_generic(void) { }
 #endif
 
+#if defined(CONFIG_PROVE_RCU) && defined(CONFIG_TASKS_RCU_GENERIC)
+void rcu_tasks_initiate_self_tests(void);
+#else
+static inline void rcu_tasks_initiate_self_tests(void) {}
+#endif
+
+
 #ifdef CONFIG_RCU_STALL_COMMON
 void rcu_sysrq_start(void);
 void rcu_sysrq_end(void);
diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
index 9deedfeec2b17..7d049883a08ac 100644
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -99,13 +99,22 @@ extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass);
+extern void _rt_mutex_lock_nest_lock(struct rt_mutex *lock, struct lockdep_map *nest_lock);
 #define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
+#define rt_mutex_lock_nest_lock(lock, nest_lock)			\
+	do {								\
+		typecheck(struct lockdep_map *, &(nest_lock)->dep_map);	\
+		_rt_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map);	\
+	} while (0)
+
 #else
 extern void rt_mutex_lock(struct rt_mutex *lock);
 #define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
+#define rt_mutex_lock_nest_lock(lock, nest_lock) rt_mutex_lock(lock)
 #endif
 
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
 extern int rt_mutex_trylock(struct rt_mutex *lock);
 
 extern void rt_mutex_unlock(struct rt_mutex *lock);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index df4817deee202..e064e5bd88f3a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -118,12 +118,8 @@ struct task_group;
 
 #define task_is_running(task)		(READ_ONCE((task)->__state) == TASK_RUNNING)
 
-#define task_is_traced(task)		((READ_ONCE(task->__state) & __TASK_TRACED) != 0)
-
 #define task_is_stopped(task)		((READ_ONCE(task->__state) & __TASK_STOPPED) != 0)
 
-#define task_is_stopped_or_traced(task)	((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0)
-
 /*
  * Special states are those that do not use the normal wait-loop pattern. See
  * the comment with set_special_state().
@@ -1081,6 +1077,10 @@ struct task_struct {
 	/* Restored if set_restore_sigmask() was used: */
 	sigset_t			saved_sigmask;
 	struct sigpending		pending;
+#ifdef CONFIG_PREEMPT_RT
+	/* TODO: move me into ->restart_block ? */
+	struct				kernel_siginfo forced_info;
+#endif
 	unsigned long			sas_ss_sp;
 	size_t				sas_ss_size;
 	unsigned int			sas_ss_flags;
@@ -1739,6 +1739,16 @@ static __always_inline bool is_percpu_thread(void)
 #endif
 }
 
+/* Is the current task guaranteed to stay on its current CPU? */
+static inline bool is_migratable(void)
+{
+#ifdef CONFIG_SMP
+	return preemptible() && !current->migration_disabled;
+#else
+	return false;
+#endif
+}
+
 /* Per-process atomic flags. */
 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
@@ -2016,6 +2026,118 @@ static inline int test_tsk_need_resched(struct task_struct *tsk)
 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+static inline void set_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int test_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY));
+}
+
+static inline int need_resched_lazy(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int need_resched_now(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+#else
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk) { }
+static inline int need_resched_lazy(void) { return 0; }
+
+static inline int need_resched_now(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+#endif
+
+#ifdef CONFIG_PREEMPT_RT
+static inline bool task_match_saved_state(struct task_struct *p, long match_state)
+{
+	return p->saved_state == match_state;
+}
+
+static inline bool task_is_traced(struct task_struct *task)
+{
+	bool traced = false;
+
+	/* in case the task is sleeping on tasklist_lock */
+	raw_spin_lock_irq(&task->pi_lock);
+	if (READ_ONCE(task->__state) & __TASK_TRACED)
+		traced = true;
+	else if (task->saved_state & __TASK_TRACED)
+		traced = true;
+	raw_spin_unlock_irq(&task->pi_lock);
+	return traced;
+}
+
+static inline bool task_is_stopped_or_traced(struct task_struct *task)
+{
+	bool traced_stopped = false;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+	if (READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED))
+		traced_stopped = true;
+	else if (task->saved_state & (__TASK_STOPPED | __TASK_TRACED))
+		traced_stopped = true;
+
+	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+	return traced_stopped;
+}
+
+#else
+
+static inline bool task_match_saved_state(struct task_struct *p, long match_state)
+{
+	return false;
+}
+
+static inline bool task_is_traced(struct task_struct *task)
+{
+	return READ_ONCE(task->__state) & __TASK_TRACED;
+}
+
+static inline bool task_is_stopped_or_traced(struct task_struct *task)
+{
+	return READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED);
+}
+#endif
+
+static inline bool task_match_state_or_saved(struct task_struct *p,
+					     long match_state)
+{
+	if (READ_ONCE(p->__state) == match_state)
+		return true;
+
+	return task_match_saved_state(p, match_state);
+}
+
+static inline bool task_match_state_lock(struct task_struct *p,
+					 long match_state)
+{
+	bool match;
+
+	raw_spin_lock_irq(&p->pi_lock);
+	match = task_match_state_or_saved(p, match_state);
+	raw_spin_unlock_irq(&p->pi_lock);
+
+	return match;
+}
+
 /*
  * cond_resched() and cond_resched_lock(): latency reduction via
  * explicit rescheduling in places that are safe. The return
@@ -2050,7 +2172,7 @@ static inline int _cond_resched(void) { return 0; }
 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */
 
 #define cond_resched() ({			\
-	___might_sleep(__FILE__, __LINE__, 0);	\
+	__might_resched(__FILE__, __LINE__, 0);	\
 	_cond_resched();			\
 })
 
@@ -2058,19 +2180,38 @@ extern int __cond_resched_lock(spinlock_t *lock);
 extern int __cond_resched_rwlock_read(rwlock_t *lock);
 extern int __cond_resched_rwlock_write(rwlock_t *lock);
 
-#define cond_resched_lock(lock) ({				\
-	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
-	__cond_resched_lock(lock);				\
+#define MIGHT_RESCHED_RCU_SHIFT		8
+#define MIGHT_RESCHED_PREEMPT_MASK	((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
+
+#ifndef CONFIG_PREEMPT_RT
+/*
+ * Non RT kernels have an elevated preempt count due to the held lock,
+ * but are not allowed to be inside a RCU read side critical section
+ */
+# define PREEMPT_LOCK_RESCHED_OFFSETS	PREEMPT_LOCK_OFFSET
+#else
+/*
+ * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
+ * cond_resched*lock() has to take that into account because it checks for
+ * preempt_count() and rcu_preempt_depth().
+ */
+# define PREEMPT_LOCK_RESCHED_OFFSETS	\
+	(PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
+#endif
+
+#define cond_resched_lock(lock) ({						\
+	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
+	__cond_resched_lock(lock);						\
 })
 
-#define cond_resched_rwlock_read(lock) ({			\
-	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
-	__cond_resched_rwlock_read(lock);			\
+#define cond_resched_rwlock_read(lock) ({					\
+	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
+	__cond_resched_rwlock_read(lock);					\
 })
 
-#define cond_resched_rwlock_write(lock) ({			\
-	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
-	__cond_resched_rwlock_write(lock);			\
+#define cond_resched_rwlock_write(lock) ({					\
+	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
+	__cond_resched_rwlock_write(lock);					\
 })
 
 static inline void cond_resched_rcu(void)
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 95fb7aaaec8de..28e9cc60f47ef 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -49,6 +49,26 @@ static inline void mmdrop(struct mm_struct *mm)
 		__mmdrop(mm);
 }
 
+#ifdef CONFIG_PREEMPT_RT
+extern void __mmdrop_delayed(struct rcu_head *rhp);
+
+/*
+ * Invoked from finish_task_switch(). Delegates the heavy lifting on RT
+ * kernels via RCU.
+ */
+static inline void mmdrop_sched(struct mm_struct *mm)
+{
+	/* Provides a full memory barrier. See mmdrop() */
+	if (atomic_dec_and_test(&mm->mm_count))
+		call_rcu(&mm->delayed_drop, __mmdrop_delayed);
+}
+#else
+static inline void mmdrop_sched(struct mm_struct *mm)
+{
+	mmdrop(mm);
+}
+#endif
+
 /**
  * mmget() - Pin the address space associated with a &struct mm_struct.
  * @mm: The address space to pin.
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index ff5aaed609695..d4861ba862167 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -116,6 +116,19 @@ static inline void put_task_struct(struct task_struct *t)
 	if (!refcount_dec_and_test(&t->usage))
 		return;
 
+	/*
+	 * In !RT, it is always safe to call __put_task_struct().
+	 * Under RT, we can only call it in preemptible context.
+	 */
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) {
+		static DEFINE_WAIT_OVERRIDE_MAP(put_task_map, LD_WAIT_SLEEP);
+
+		lock_map_acquire_try(&put_task_map);
+		__put_task_struct(t);
+		lock_map_release(&put_task_map);
+		return;
+	}
+
 	/*
 	 * under PREEMPT_RT, we can't call put_task_struct
 	 * in atomic context because it will indirectly
@@ -136,10 +149,7 @@ static inline void put_task_struct(struct task_struct *t)
 	 * when it fails to fork a process. Therefore, there is no
 	 * way it can conflict with put_task_struct().
 	 */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT) && !preemptible())
-		call_rcu(&t->rcu, __put_task_struct_rcu_cb);
-	else
-		__put_task_struct(t);
+	call_rcu(&t->rcu, __put_task_struct_rcu_cb);
 }
 
 DEFINE_FREE(put_task, struct task_struct *, if (_T) put_task_struct(_T))
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 979586e34da8f..3f33747e980ba 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -7,6 +7,7 @@
 #ifndef _LINUX_SERIAL_8250_H
 #define _LINUX_SERIAL_8250_H
 
+#include <linux/atomic.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/platform_device.h>
@@ -125,6 +126,8 @@ struct uart_8250_port {
 #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
 	unsigned char		msr_saved_flags;
 
+	atomic_t		console_printing;
+
 	struct uart_8250_dma	*dma;
 	const struct uart_8250_ops *ops;
 
@@ -180,6 +183,8 @@ void serial8250_init_port(struct uart_8250_port *up);
 void serial8250_set_defaults(struct uart_8250_port *up);
 void serial8250_console_write(struct uart_8250_port *up, const char *s,
 			      unsigned int count);
+void serial8250_console_write_atomic(struct uart_8250_port *up, const char *s,
+				     unsigned int count);
 int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
 int serial8250_console_exit(struct uart_port *port);
 
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 24ceeab1b509f..f20d895d64044 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -301,6 +301,7 @@ struct sk_buff_head {
 
 	__u32		qlen;
 	spinlock_t	lock;
+	raw_spinlock_t	raw_lock;
 };
 
 struct sk_buff;
@@ -1988,6 +1989,12 @@ static inline void skb_queue_head_init(struct sk_buff_head *list)
 	__skb_queue_head_init(list);
 }
 
+static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
+{
+	raw_spin_lock_init(&list->raw_lock);
+	__skb_queue_head_init(list);
+}
+
 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
 		struct lock_class_key *class)
 {
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 510519e8a1eb7..7ac9fdb5ad091 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -268,6 +268,9 @@ static inline int get_boot_cpu_id(void)
 #define get_cpu()		({ preempt_disable(); __smp_processor_id(); })
 #define put_cpu()		preempt_enable()
 
+#define get_cpu_light()		({ migrate_disable(); __smp_processor_id(); })
+#define put_cpu_light()		migrate_enable()
+
 /*
  * Callback to arch code if there's nosmp or maxcpus=0 on the
  * boot command line:
diff --git a/include/linux/spinlock_types_up.h b/include/linux/spinlock_types_up.h
index c09b6407ae1b3..7f86a2016ac5c 100644
--- a/include/linux/spinlock_types_up.h
+++ b/include/linux/spinlock_types_up.h
@@ -1,7 +1,7 @@
 #ifndef __LINUX_SPINLOCK_TYPES_UP_H
 #define __LINUX_SPINLOCK_TYPES_UP_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
 # error "please don't include this file directly"
 #endif
 
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 9a073535c0bdd..0536fbba7f69e 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -177,7 +177,17 @@ static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti
 	clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
 #endif /* !CONFIG_GENERIC_ENTRY */
 
-#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+#ifdef CONFIG_PREEMPT_LAZY
+#define tif_need_resched()	(test_thread_flag(TIF_NEED_RESCHED) || \
+				 test_thread_flag(TIF_NEED_RESCHED_LAZY))
+#define tif_need_resched_now()	(test_thread_flag(TIF_NEED_RESCHED))
+#define tif_need_resched_lazy()	test_thread_flag(TIF_NEED_RESCHED_LAZY)
+
+#else
+#define tif_need_resched()	test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_now()	test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_lazy()	0
+#endif
 
 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
 static inline int arch_within_stack_frames(const void * const stack,
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index aff7a43c15e44..c7f156093008f 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -69,6 +69,7 @@ struct trace_entry {
 	unsigned char		flags;
 	unsigned char		preempt_count;
 	int			pid;
+	unsigned char		preempt_lazy_count;
 };
 
 #define TRACE_EVENT_TYPE_MAX						\
@@ -158,9 +159,10 @@ static inline void tracing_generic_entry_update(struct trace_entry *entry,
 						unsigned int trace_ctx)
 {
 	entry->preempt_count		= trace_ctx & 0xff;
+	entry->preempt_lazy_count	= (trace_ctx >> 16) & 0xff;
 	entry->pid			= current->pid;
 	entry->type			= type;
-	entry->flags =			trace_ctx >> 16;
+	entry->flags			= trace_ctx >> 24;
 }
 
 unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status);
@@ -173,6 +175,7 @@ enum trace_flag_type {
 	TRACE_FLAG_SOFTIRQ		= 0x10,
 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
 	TRACE_FLAG_NMI			= 0x40,
+	TRACE_FLAG_NEED_RESCHED_LAZY	= 0x80,
 };
 
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h
index 6a0f2097d3709..6ad4e9032d538 100644
--- a/include/linux/u64_stats_sync.h
+++ b/include/linux/u64_stats_sync.h
@@ -83,6 +83,11 @@ static inline u64 u64_stats_read(const u64_stats_t *p)
 	return local64_read(&p->v);
 }
 
+static inline void u64_stats_set(u64_stats_t *p, u64 val)
+{
+	local64_set(&p->v, val);
+}
+
 static inline void u64_stats_add(u64_stats_t *p, unsigned long val)
 {
 	local64_add(val, &p->v);
@@ -104,6 +109,11 @@ static inline u64 u64_stats_read(const u64_stats_t *p)
 	return p->v;
 }
 
+static inline void u64_stats_set(u64_stats_t *p, u64 val)
+{
+	p->v = val;
+}
+
 static inline void u64_stats_add(u64_stats_t *p, unsigned long val)
 {
 	p->v += val;
diff --git a/include/net/act_api.h b/include/net/act_api.h
index 47b0a8feaa71a..3ecf12bb2e4fc 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -30,13 +30,13 @@ struct tc_action {
 	atomic_t			tcfa_bindcnt;
 	int				tcfa_action;
 	struct tcf_t			tcfa_tm;
-	struct gnet_stats_basic_packed	tcfa_bstats;
-	struct gnet_stats_basic_packed	tcfa_bstats_hw;
+	struct gnet_stats_basic_sync	tcfa_bstats;
+	struct gnet_stats_basic_sync	tcfa_bstats_hw;
 	struct gnet_stats_queue		tcfa_qstats;
 	struct net_rate_estimator __rcu *tcfa_rate_est;
 	spinlock_t			tcfa_lock;
-	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
-	struct gnet_stats_basic_cpu __percpu *cpu_bstats_hw;
+	struct gnet_stats_basic_sync __percpu *cpu_bstats;
+	struct gnet_stats_basic_sync __percpu *cpu_bstats_hw;
 	struct gnet_stats_queue __percpu *cpu_qstats;
 	struct tc_cookie	__rcu *act_cookie;
 	struct tcf_chain	__rcu *goto_chain;
@@ -209,7 +209,7 @@ static inline void tcf_action_update_bstats(struct tc_action *a,
 					    struct sk_buff *skb)
 {
 	if (likely(a->cpu_bstats)) {
-		bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), skb);
+		bstats_update(this_cpu_ptr(a->cpu_bstats), skb);
 		return;
 	}
 	spin_lock(&a->tcfa_lock);
diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h
index 1424e02cef90c..7aa2b8e1fb298 100644
--- a/include/net/gen_stats.h
+++ b/include/net/gen_stats.h
@@ -7,14 +7,17 @@
 #include <linux/rtnetlink.h>
 #include <linux/pkt_sched.h>
 
-/* Note: this used to be in include/uapi/linux/gen_stats.h */
-struct gnet_stats_basic_packed {
-	__u64	bytes;
-	__u64	packets;
-};
-
-struct gnet_stats_basic_cpu {
-	struct gnet_stats_basic_packed bstats;
+/* Throughput stats.
+ * Must be initialized beforehand with gnet_stats_basic_sync_init().
+ *
+ * If no reads can ever occur parallel to writes (e.g. stack-allocated
+ * bstats), then the internal stat values can be written to and read
+ * from directly. Otherwise, use _bstats_set/update() for writes and
+ * gnet_stats_add_basic() for reads.
+ */
+struct gnet_stats_basic_sync {
+	u64_stats_t bytes;
+	u64_stats_t packets;
 	struct u64_stats_sync syncp;
 } __aligned(2 * sizeof(u64));
 
@@ -34,6 +37,7 @@ struct gnet_dump {
 	struct tc_stats   tc_stats;
 };
 
+void gnet_stats_basic_sync_init(struct gnet_stats_basic_sync *b);
 int gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
 			  struct gnet_dump *d, int padattr);
 
@@ -42,41 +46,38 @@ int gnet_stats_start_copy_compat(struct sk_buff *skb, int type,
 				 spinlock_t *lock, struct gnet_dump *d,
 				 int padattr);
 
-int gnet_stats_copy_basic(const seqcount_t *running,
-			  struct gnet_dump *d,
-			  struct gnet_stats_basic_cpu __percpu *cpu,
-			  struct gnet_stats_basic_packed *b);
-void __gnet_stats_copy_basic(const seqcount_t *running,
-			     struct gnet_stats_basic_packed *bstats,
-			     struct gnet_stats_basic_cpu __percpu *cpu,
-			     struct gnet_stats_basic_packed *b);
-int gnet_stats_copy_basic_hw(const seqcount_t *running,
-			     struct gnet_dump *d,
-			     struct gnet_stats_basic_cpu __percpu *cpu,
-			     struct gnet_stats_basic_packed *b);
+int gnet_stats_copy_basic(struct gnet_dump *d,
+			  struct gnet_stats_basic_sync __percpu *cpu,
+			  struct gnet_stats_basic_sync *b, bool running);
+void gnet_stats_add_basic(struct gnet_stats_basic_sync *bstats,
+			  struct gnet_stats_basic_sync __percpu *cpu,
+			  struct gnet_stats_basic_sync *b, bool running);
+int gnet_stats_copy_basic_hw(struct gnet_dump *d,
+			     struct gnet_stats_basic_sync __percpu *cpu,
+			     struct gnet_stats_basic_sync *b, bool running);
 int gnet_stats_copy_rate_est(struct gnet_dump *d,
 			     struct net_rate_estimator __rcu **ptr);
 int gnet_stats_copy_queue(struct gnet_dump *d,
 			  struct gnet_stats_queue __percpu *cpu_q,
 			  struct gnet_stats_queue *q, __u32 qlen);
-void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
-			     const struct gnet_stats_queue __percpu *cpu_q,
-			     const struct gnet_stats_queue *q, __u32 qlen);
+void gnet_stats_add_queue(struct gnet_stats_queue *qstats,
+			  const struct gnet_stats_queue __percpu *cpu_q,
+			  const struct gnet_stats_queue *q);
 int gnet_stats_copy_app(struct gnet_dump *d, void *st, int len);
 
 int gnet_stats_finish_copy(struct gnet_dump *d);
 
-int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
-		      struct gnet_stats_basic_cpu __percpu *cpu_bstats,
+int gen_new_estimator(struct gnet_stats_basic_sync *bstats,
+		      struct gnet_stats_basic_sync __percpu *cpu_bstats,
 		      struct net_rate_estimator __rcu **rate_est,
 		      spinlock_t *lock,
-		      seqcount_t *running, struct nlattr *opt);
+		      bool running, struct nlattr *opt);
 void gen_kill_estimator(struct net_rate_estimator __rcu **ptr);
-int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
-			  struct gnet_stats_basic_cpu __percpu *cpu_bstats,
+int gen_replace_estimator(struct gnet_stats_basic_sync *bstats,
+			  struct gnet_stats_basic_sync __percpu *cpu_bstats,
 			  struct net_rate_estimator __rcu **ptr,
 			  spinlock_t *lock,
-			  seqcount_t *running, struct nlattr *opt);
+			  bool running, struct nlattr *opt);
 bool gen_estimator_active(struct net_rate_estimator __rcu **ptr);
 bool gen_estimator_read(struct net_rate_estimator __rcu **ptr,
 			struct gnet_stats_rate_est64 *sample);
diff --git a/include/net/netfilter/xt_rateest.h b/include/net/netfilter/xt_rateest.h
index 832ab69efda57..4c3809e141f4f 100644
--- a/include/net/netfilter/xt_rateest.h
+++ b/include/net/netfilter/xt_rateest.h
@@ -6,7 +6,7 @@
 
 struct xt_rateest {
 	/* keep lock and bstats on same cache line to speedup xt_rateest_tg() */
-	struct gnet_stats_basic_packed	bstats;
+	struct gnet_stats_basic_sync	bstats;
 	spinlock_t			lock;
 
 
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 83a6d07921806..4a5833108083f 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -765,7 +765,7 @@ struct tc_cookie {
 };
 
 struct tc_qopt_offload_stats {
-	struct gnet_stats_basic_packed *bstats;
+	struct gnet_stats_basic_sync *bstats;
 	struct gnet_stats_queue *qstats;
 };
 
@@ -885,7 +885,7 @@ struct tc_gred_qopt_offload_params {
 };
 
 struct tc_gred_qopt_offload_stats {
-	struct gnet_stats_basic_packed bstats[MAX_DPs];
+	struct gnet_stats_basic_sync bstats[MAX_DPs];
 	struct gnet_stats_queue qstats[MAX_DPs];
 	struct red_stats *xstats[MAX_DPs];
 };
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index dd6203f3f0a5e..2decbfcc59277 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -40,6 +40,13 @@ enum qdisc_state_t {
 	__QDISC_STATE_DRAINING,
 };
 
+enum qdisc_state2_t {
+	/* Only for !TCQ_F_NOLOCK qdisc. Never access it directly.
+	 * Use qdisc_run_begin/end() or qdisc_is_running() instead.
+	 */
+	__QDISC_STATE2_RUNNING,
+};
+
 #define QDISC_STATE_MISSED	BIT(__QDISC_STATE_MISSED)
 #define QDISC_STATE_DRAINING	BIT(__QDISC_STATE_DRAINING)
 
@@ -97,7 +104,7 @@ struct Qdisc {
 	struct netdev_queue	*dev_queue;
 
 	struct net_rate_estimator __rcu *rate_est;
-	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
+	struct gnet_stats_basic_sync __percpu *cpu_bstats;
 	struct gnet_stats_queue	__percpu *cpu_qstats;
 	int			pad;
 	refcount_t		refcnt;
@@ -107,10 +114,10 @@ struct Qdisc {
 	 */
 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
 	struct qdisc_skb_head	q;
-	struct gnet_stats_basic_packed bstats;
-	seqcount_t		running;
+	struct gnet_stats_basic_sync bstats;
 	struct gnet_stats_queue	qstats;
 	unsigned long		state;
+	unsigned long		state2; /* must be written under qdisc spinlock */
 	struct Qdisc            *next_sched;
 	struct sk_buff_head	skb_bad_txq;
 
@@ -143,11 +150,15 @@ static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
 	return NULL;
 }
 
+/* For !TCQ_F_NOLOCK qdisc: callers must either call this within a qdisc
+ * root_lock section, or provide their own memory barriers -- ordering
+ * against qdisc_run_begin/end() atomic bit operations.
+ */
 static inline bool qdisc_is_running(struct Qdisc *qdisc)
 {
 	if (qdisc->flags & TCQ_F_NOLOCK)
 		return spin_is_locked(&qdisc->seqlock);
-	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
+	return test_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);
 }
 
 static inline bool nolock_qdisc_is_empty(const struct Qdisc *qdisc)
@@ -167,6 +178,9 @@ static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
 	return !READ_ONCE(qdisc->q.qlen);
 }
 
+/* For !TCQ_F_NOLOCK qdisc, qdisc_run_begin/end() must be invoked with
+ * the qdisc root lock acquired.
+ */
 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
 {
 	if (qdisc->flags & TCQ_F_NOLOCK) {
@@ -186,15 +200,8 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc)
 		 * when testing it in qdisc_run_end()
 		 */
 		return spin_trylock(&qdisc->seqlock);
-	} else if (qdisc_is_running(qdisc)) {
-		return false;
 	}
-	/* Variant of write_seqcount_begin() telling lockdep a trylock
-	 * was attempted.
-	 */
-	raw_write_seqcount_begin(&qdisc->running);
-	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
-	return true;
+	return !__test_and_set_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);
 }
 
 static inline void qdisc_run_end(struct Qdisc *qdisc)
@@ -212,7 +219,7 @@ static inline void qdisc_run_end(struct Qdisc *qdisc)
 				      &qdisc->state)))
 			__netif_schedule(qdisc);
 	} else {
-		write_seqcount_end(&qdisc->running);
+		__clear_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);
 	}
 }
 
@@ -576,14 +583,6 @@ static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
 	return qdisc_lock(root);
 }
 
-static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
-{
-	struct Qdisc *root = qdisc_root_sleeping(qdisc);
-
-	ASSERT_RTNL();
-	return &root->running;
-}
-
 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
 {
 	return qdisc->dev_queue->dev;
@@ -842,14 +841,16 @@ static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	return sch->enqueue(skb, sch, to_free);
 }
 
-static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
+static inline void _bstats_update(struct gnet_stats_basic_sync *bstats,
 				  __u64 bytes, __u32 packets)
 {
-	bstats->bytes += bytes;
-	bstats->packets += packets;
+	u64_stats_update_begin(&bstats->syncp);
+	u64_stats_add(&bstats->bytes, bytes);
+	u64_stats_add(&bstats->packets, packets);
+	u64_stats_update_end(&bstats->syncp);
 }
 
-static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
+static inline void bstats_update(struct gnet_stats_basic_sync *bstats,
 				 const struct sk_buff *skb)
 {
 	_bstats_update(bstats,
@@ -857,26 +858,10 @@ static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
 }
 
-static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
-				      __u64 bytes, __u32 packets)
-{
-	u64_stats_update_begin(&bstats->syncp);
-	_bstats_update(&bstats->bstats, bytes, packets);
-	u64_stats_update_end(&bstats->syncp);
-}
-
-static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
-				     const struct sk_buff *skb)
-{
-	u64_stats_update_begin(&bstats->syncp);
-	bstats_update(&bstats->bstats, skb);
-	u64_stats_update_end(&bstats->syncp);
-}
-
 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
 					   const struct sk_buff *skb)
 {
-	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(sch->cpu_bstats), skb);
 }
 
 static inline void qdisc_bstats_update(struct Qdisc *sch,
@@ -965,10 +950,9 @@ static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
 					     __u32 *backlog)
 {
 	struct gnet_stats_queue qstats = { 0 };
-	__u32 len = qdisc_qlen_sum(sch);
 
-	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
-	*qlen = qstats.qlen;
+	gnet_stats_add_queue(&qstats, sch->cpu_qstats, &sch->qstats);
+	*qlen = qstats.qlen + qdisc_qlen(sch);
 	*backlog = qstats.backlog;
 }
 
@@ -1328,7 +1312,7 @@ void psched_ppscfg_precompute(struct psched_pktrate *r, u64 pktrate64);
 struct mini_Qdisc {
 	struct tcf_proto *filter_list;
 	struct tcf_block *block;
-	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
+	struct gnet_stats_basic_sync __percpu *cpu_bstats;
 	struct gnet_stats_queue	__percpu *cpu_qstats;
 	struct rcu_head rcu;
 };
@@ -1336,7 +1320,7 @@ struct mini_Qdisc {
 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
 						const struct sk_buff *skb)
 {
-	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(miniq->cpu_bstats), skb);
 }
 
 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
diff --git a/init/Kconfig b/init/Kconfig
index b66259bfd2352..75095f406a507 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -910,7 +910,7 @@ config NUMA_BALANCING
 	bool "Memory placement aware NUMA scheduler"
 	depends on ARCH_SUPPORTS_NUMA_BALANCING
 	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
-	depends on SMP && NUMA && MIGRATION
+	depends on SMP && NUMA && MIGRATION && !PREEMPT_RT
 	help
 	  This option adds support for automatic NUMA aware memory/task placement.
 	  The mechanism is quite primitive and is based on migrating memory when
@@ -1905,6 +1905,7 @@ choice
 
 config SLAB
 	bool "SLAB"
+	depends on !PREEMPT_RT
 	select HAVE_HARDENED_USERCOPY_ALLOCATOR
 	help
 	  The regular slab allocator that is established and known to work
@@ -1925,6 +1926,7 @@ config SLUB
 config SLOB
 	depends on EXPERT
 	bool "SLOB (Simple Allocator)"
+	depends on !PREEMPT_RT
 	help
 	   SLOB replaces the stock allocator with a drastically simpler
 	   allocator. SLOB is generally more space efficient but
diff --git a/init/main.c b/init/main.c
index 4e9c76a0e5a47..3e14b75a94d45 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1615,6 +1615,7 @@ static noinline void __init kernel_init_freeable(void)
 
 	rcu_init_tasks_generic();
 	do_pre_smp_initcalls();
+	rcu_tasks_initiate_self_tests();
 	lockup_detector_init();
 
 	smp_init();
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 5876e30c5740d..5df0776264c20 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -1,5 +1,11 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+config HAVE_PREEMPT_LAZY
+	bool
+
+config PREEMPT_LAZY
+	def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT
+
 choice
 	prompt "Preemption Model"
 	default PREEMPT_NONE
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index b80d125dcea97..7a7356c3ddeb6 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2483,27 +2483,30 @@ static void bpf_link_put_deferred(struct work_struct *work)
 	bpf_link_free(link);
 }
 
-/* bpf_link_put can be called from atomic context, but ensures that resources
- * are freed from process context
+/* bpf_link_put might be called from atomic context. It needs to be called
+ * from sleepable context in order to acquire sleeping locks during the process.
  */
 void bpf_link_put(struct bpf_link *link)
 {
 	if (!atomic64_dec_and_test(&link->refcnt))
 		return;
 
-	if (in_atomic()) {
-		INIT_WORK(&link->work, bpf_link_put_deferred);
-		schedule_work(&link->work);
-	} else {
-		bpf_link_free(link);
-	}
+	INIT_WORK(&link->work, bpf_link_put_deferred);
+	schedule_work(&link->work);
+}
+
+static void bpf_link_put_direct(struct bpf_link *link)
+{
+	if (!atomic64_dec_and_test(&link->refcnt))
+		return;
+	bpf_link_free(link);
 }
 
 static int bpf_link_release(struct inode *inode, struct file *filp)
 {
 	struct bpf_link *link = filp->private_data;
 
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 	return 0;
 }
 
@@ -4394,7 +4397,7 @@ static int link_update(union bpf_attr *attr)
 	if (ret)
 		bpf_prog_put(new_prog);
 out_put_link:
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 	return ret;
 }
 
@@ -4417,7 +4420,7 @@ static int link_detach(union bpf_attr *attr)
 	else
 		ret = -EOPNOTSUPP;
 
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 	return ret;
 }
 
@@ -4468,7 +4471,7 @@ static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
 
 	fd = bpf_link_new_fd(link);
 	if (fd < 0)
-		bpf_link_put(link);
+		bpf_link_put_direct(link);
 
 	return fd;
 }
@@ -4545,7 +4548,7 @@ static int bpf_iter_create(union bpf_attr *attr)
 		return PTR_ERR(link);
 
 	err = bpf_iter_new_fd(link);
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 
 	return err;
 }
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index 1486768f23185..bb3b805436c49 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -156,8 +156,9 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep)
 		raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock,
 						       cpu);
 		struct cgroup *pos = NULL;
+		unsigned long flags;
 
-		raw_spin_lock(cpu_lock);
+		raw_spin_lock_irqsave(cpu_lock, flags);
 		while ((pos = cgroup_rstat_cpu_pop_updated(pos, cgrp, cpu))) {
 			struct cgroup_subsys_state *css;
 
@@ -169,7 +170,7 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep)
 				css->ss->css_rstat_flush(css, cpu);
 			rcu_read_unlock();
 		}
-		raw_spin_unlock(cpu_lock);
+		raw_spin_unlock_irqrestore(cpu_lock, flags);
 
 		/* if @may_sleep, play nice and yield if necessary */
 		if (may_sleep && (need_resched() ||
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index f40ca4f09afce..0f674646943d7 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -239,35 +239,42 @@ NOKPROBE_SYMBOL(kgdb_call_nmi_hook);
 static DEFINE_PER_CPU(call_single_data_t, kgdb_roundup_csd) =
 	CSD_INIT(kgdb_call_nmi_hook, NULL);
 
-void __weak kgdb_roundup_cpus(void)
+void __weak kgdb_roundup_cpu(unsigned int cpu)
 {
 	call_single_data_t *csd;
+	int ret;
+
+	csd = &per_cpu(kgdb_roundup_csd, cpu);
+
+	/*
+	 * If it didn't round up last time, don't try again
+	 * since smp_call_function_single_async() will block.
+	 *
+	 * If rounding_up is false then we know that the
+	 * previous call must have at least started and that
+	 * means smp_call_function_single_async() won't block.
+	 */
+	if (kgdb_info[cpu].rounding_up)
+		return;
+	kgdb_info[cpu].rounding_up = true;
+
+	ret = smp_call_function_single_async(cpu, csd);
+	if (ret)
+		kgdb_info[cpu].rounding_up = false;
+}
+NOKPROBE_SYMBOL(kgdb_roundup_cpu);
+
+void __weak kgdb_roundup_cpus(void)
+{
 	int this_cpu = raw_smp_processor_id();
 	int cpu;
-	int ret;
 
 	for_each_online_cpu(cpu) {
 		/* No need to roundup ourselves */
 		if (cpu == this_cpu)
 			continue;
 
-		csd = &per_cpu(kgdb_roundup_csd, cpu);
-
-		/*
-		 * If it didn't round up last time, don't try again
-		 * since smp_call_function_single_async() will block.
-		 *
-		 * If rounding_up is false then we know that the
-		 * previous call must have at least started and that
-		 * means smp_call_function_single_async() won't block.
-		 */
-		if (kgdb_info[cpu].rounding_up)
-			continue;
-		kgdb_info[cpu].rounding_up = true;
-
-		ret = smp_call_function_single_async(cpu, csd);
-		if (ret)
-			kgdb_info[cpu].rounding_up = false;
+		kgdb_roundup_cpu(cpu);
 	}
 }
 NOKPROBE_SYMBOL(kgdb_roundup_cpus);
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 1d016767179f5..c82b0660fcff5 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -572,6 +572,7 @@ static void kdb_msg_write(const char *msg, int msg_len)
 		cp++;
 	}
 
+	/* mirror output on atomic consoles */
 	for_each_console(c) {
 		if (!(c->flags & CON_ENABLED))
 			continue;
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index d11d4047a0ca8..9327f590cd866 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -165,9 +165,17 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
 
 		local_irq_enable_exit_to_user(ti_work);
 
-		if (ti_work & _TIF_NEED_RESCHED)
+		if (ti_work & _TIF_NEED_RESCHED_MASK)
 			schedule();
 
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+		if (unlikely(current->forced_info.si_signo)) {
+			struct task_struct *t = current;
+			force_sig_info(&t->forced_info);
+			t->forced_info.si_signo = 0;
+		}
+#endif
+
 		if (ti_work & _TIF_UPROBE)
 			uprobe_notify_resume(regs);
 
@@ -394,7 +402,7 @@ void irqentry_exit_cond_resched(void)
 		rcu_irq_exit_check_preempt();
 		if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
 			WARN_ON_ONCE(!on_thread_stack());
-		if (need_resched())
+		if (should_resched(0))
 			preempt_schedule_irq();
 	}
 }
diff --git a/kernel/exit.c b/kernel/exit.c
index 776994c28887a..18c767ecf74d0 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -64,6 +64,7 @@
 #include <linux/rcuwait.h>
 #include <linux/compat.h>
 #include <linux/io_uring.h>
+#include <linux/kprobes.h>
 #include <linux/sysfs.h>
 
 #include <linux/uaccess.h>
@@ -221,8 +222,14 @@ static void delayed_put_task_struct(struct rcu_head *rhp)
 {
 	struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
 
+	kprobe_flush_task(tsk);
 	perf_event_delayed_put(tsk);
 	trace_sched_process_free(tsk);
+
+	/* RT enabled kernels delay freeing the VMAP'ed task stack */
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		put_task_stack(tsk);
+
 	put_task_struct(tsk);
 }
 
diff --git a/kernel/fork.c b/kernel/fork.c
index f55be5303dc7a..9bd35d89970fb 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -291,7 +291,10 @@ static inline void free_thread_stack(struct task_struct *tsk)
 			return;
 		}
 
-		vfree_atomic(tsk->stack);
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+			vfree_atomic(tsk->stack);
+		else
+			vfree(tsk->stack);
 		return;
 	}
 #endif
@@ -711,6 +714,19 @@ void __mmdrop(struct mm_struct *mm)
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
 
+#ifdef CONFIG_PREEMPT_RT
+/*
+ * RCU callback for delayed mm drop. Not strictly RCU, but call_rcu() is
+ * by far the least expensive way to do that.
+ */
+void __mmdrop_delayed(struct rcu_head *rhp)
+{
+	struct mm_struct *mm = container_of(rhp, struct mm_struct, delayed_drop);
+
+	__mmdrop(mm);
+}
+#endif
+
 static void mmdrop_async_fn(struct work_struct *work)
 {
 	struct mm_struct *mm;
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index d5010a24ed16e..7334240091ff3 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -665,6 +665,29 @@ int generic_handle_irq(unsigned int irq)
 }
 EXPORT_SYMBOL_GPL(generic_handle_irq);
 
+/**
+ * generic_handle_irq_safe - Invoke the handler for a particular irq from any
+ *			     context.
+ * @irq:	The irq number to handle
+ *
+ * Returns:	0 on success, a negative value on error.
+ *
+ * This function can be called from any context (IRQ or process context). It
+ * will report an error if not invoked from IRQ context and the irq has been
+ * marked to enforce IRQ-context only.
+ */
+int generic_handle_irq_safe(unsigned int irq)
+{
+	unsigned long flags;
+	int ret;
+
+	local_irq_save(flags);
+	ret = handle_irq_desc(irq_to_desc(irq));
+	local_irq_restore(flags);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
+
 #ifdef CONFIG_IRQ_DOMAIN
 /**
  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index ce0433446a8ed..57a00b5accb33 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1301,6 +1301,8 @@ static int irq_thread(void *data)
 
 	irq_thread_set_ready(desc, action);
 
+	sched_set_fifo(current);
+
 	if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
 					   &action->thread_flags))
 		handler_fn = irq_forced_thread_fn;
@@ -1466,8 +1468,6 @@ setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
 	if (IS_ERR(t))
 		return PTR_ERR(t);
 
-	sched_set_fifo(t);
-
 	/*
 	 * We keep the reference to the task struct even if
 	 * the thread dies to avoid that the interrupt code
@@ -2861,7 +2861,7 @@ EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
  *	This call sets the internal irqchip state of an interrupt,
  *	depending on the value of @which.
  *
- *	This function should be called with preemption disabled if the
+ *	This function should be called with migration disabled if the
  *	interrupt controller has per-cpu registers.
  */
 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index c481d84583257..02b2daf074414 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -447,6 +447,10 @@ MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true");
 
 static int __init irqfixup_setup(char *str)
 {
+	if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		pr_warn("irqfixup boot option not supported with PREEMPT_RT\n");
+		return 1;
+	}
 	irqfixup = 1;
 	printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
 	printk(KERN_WARNING "This may impact system performance.\n");
@@ -459,6 +463,10 @@ module_param(irqfixup, int, 0644);
 
 static int __init irqpoll_setup(char *str)
 {
+	if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		pr_warn("irqpoll boot option not supported with PREEMPT_RT\n");
+		return 1;
+	}
 	irqfixup = 2;
 	printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
 				"enabled\n");
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index db8c248ebc8c8..f7df715ec28e6 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -18,11 +18,36 @@
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/smp.h>
+#include <linux/smpboot.h>
 #include <asm/processor.h>
 #include <linux/kasan.h>
 
 static DEFINE_PER_CPU(struct llist_head, raised_list);
 static DEFINE_PER_CPU(struct llist_head, lazy_list);
+static DEFINE_PER_CPU(struct task_struct *, irq_workd);
+
+static void wake_irq_workd(void)
+{
+	struct task_struct *tsk = __this_cpu_read(irq_workd);
+
+	if (!llist_empty(this_cpu_ptr(&lazy_list)) && tsk)
+		wake_up_process(tsk);
+}
+
+#ifdef CONFIG_SMP
+static void irq_work_wake(struct irq_work *entry)
+{
+	wake_irq_workd();
+}
+
+static DEFINE_PER_CPU(struct irq_work, irq_work_wakeup) =
+	IRQ_WORK_INIT_HARD(irq_work_wake);
+#endif
+
+static int irq_workd_should_run(unsigned int cpu)
+{
+	return !llist_empty(this_cpu_ptr(&lazy_list));
+}
 
 /*
  * Claim the entry so that no one else will poke at it.
@@ -52,15 +77,29 @@ void __weak arch_irq_work_raise(void)
 /* Enqueue on current CPU, work must already be claimed and preempt disabled */
 static void __irq_work_queue_local(struct irq_work *work)
 {
+	struct llist_head *list;
+	bool rt_lazy_work = false;
+	bool lazy_work = false;
+	int work_flags;
+
+	work_flags = atomic_read(&work->node.a_flags);
+	if (work_flags & IRQ_WORK_LAZY)
+		lazy_work = true;
+	else if (IS_ENABLED(CONFIG_PREEMPT_RT) &&
+		 !(work_flags & IRQ_WORK_HARD_IRQ))
+		rt_lazy_work = true;
+
+	if (lazy_work || rt_lazy_work)
+		list = this_cpu_ptr(&lazy_list);
+	else
+		list = this_cpu_ptr(&raised_list);
+
+	if (!llist_add(&work->node.llist, list))
+		return;
+
 	/* If the work is "lazy", handle it from next tick if any */
-	if (atomic_read(&work->node.a_flags) & IRQ_WORK_LAZY) {
-		if (llist_add(&work->node.llist, this_cpu_ptr(&lazy_list)) &&
-		    tick_nohz_tick_stopped())
-			arch_irq_work_raise();
-	} else {
-		if (llist_add(&work->node.llist, this_cpu_ptr(&raised_list)))
-			arch_irq_work_raise();
-	}
+	if (!lazy_work || tick_nohz_tick_stopped())
+		arch_irq_work_raise();
 }
 
 /* Enqueue the irq work @work on the current CPU */
@@ -104,17 +143,34 @@ bool irq_work_queue_on(struct irq_work *work, int cpu)
 	if (cpu != smp_processor_id()) {
 		/* Arch remote IPI send/receive backend aren't NMI safe */
 		WARN_ON_ONCE(in_nmi());
+
+		/*
+		 * On PREEMPT_RT the items which are not marked as
+		 * IRQ_WORK_HARD_IRQ are added to the lazy list and a HARD work
+		 * item is used on the remote CPU to wake the thread.
+		 */
+		if (IS_ENABLED(CONFIG_PREEMPT_RT) &&
+		    !(atomic_read(&work->node.a_flags) & IRQ_WORK_HARD_IRQ)) {
+
+			if (!llist_add(&work->node.llist, &per_cpu(lazy_list, cpu)))
+				goto out;
+
+			work = &per_cpu(irq_work_wakeup, cpu);
+			if (!irq_work_claim(work))
+				goto out;
+		}
+
 		__smp_call_single_queue(cpu, &work->node.llist);
 	} else {
 		__irq_work_queue_local(work);
 	}
+out:
 	preempt_enable();
 
 	return true;
 #endif /* CONFIG_SMP */
 }
 
-
 bool irq_work_needs_cpu(void)
 {
 	struct llist_head *raised, *lazy;
@@ -160,6 +216,10 @@ void irq_work_single(void *arg)
 	 * else claimed it meanwhile.
 	 */
 	(void)atomic_cmpxchg(&work->node.a_flags, flags, flags & ~IRQ_WORK_BUSY);
+
+	if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) ||
+	    !arch_irq_work_has_interrupt())
+		rcuwait_wake_up(&work->irqwait);
 }
 
 static void irq_work_run_list(struct llist_head *list)
@@ -167,7 +227,12 @@ static void irq_work_run_list(struct llist_head *list)
 	struct irq_work *work, *tmp;
 	struct llist_node *llnode;
 
-	BUG_ON(!irqs_disabled());
+	/*
+	 * On PREEMPT_RT IRQ-work which is not marked as HARD will be processed
+	 * in a per-CPU thread in preemptible context. Only the items which are
+	 * marked as IRQ_WORK_HARD_IRQ will be processed in hardirq context.
+	 */
+	BUG_ON(!irqs_disabled() && !IS_ENABLED(CONFIG_PREEMPT_RT));
 
 	if (llist_empty(list))
 		return;
@@ -184,7 +249,10 @@ static void irq_work_run_list(struct llist_head *list)
 void irq_work_run(void)
 {
 	irq_work_run_list(this_cpu_ptr(&raised_list));
-	irq_work_run_list(this_cpu_ptr(&lazy_list));
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		irq_work_run_list(this_cpu_ptr(&lazy_list));
+	else
+		wake_irq_workd();
 }
 EXPORT_SYMBOL_GPL(irq_work_run);
 
@@ -194,7 +262,11 @@ void irq_work_tick(void)
 
 	if (!llist_empty(raised) && !arch_irq_work_has_interrupt())
 		irq_work_run_list(raised);
-	irq_work_run_list(this_cpu_ptr(&lazy_list));
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		irq_work_run_list(this_cpu_ptr(&lazy_list));
+	else
+		wake_irq_workd();
 }
 
 /*
@@ -204,8 +276,42 @@ void irq_work_tick(void)
 void irq_work_sync(struct irq_work *work)
 {
 	lockdep_assert_irqs_enabled();
+	might_sleep();
+
+	if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) ||
+	    !arch_irq_work_has_interrupt()) {
+		rcuwait_wait_event(&work->irqwait, !irq_work_is_busy(work),
+				   TASK_UNINTERRUPTIBLE);
+		return;
+	}
 
 	while (irq_work_is_busy(work))
 		cpu_relax();
 }
 EXPORT_SYMBOL_GPL(irq_work_sync);
+
+static void run_irq_workd(unsigned int cpu)
+{
+	irq_work_run_list(this_cpu_ptr(&lazy_list));
+}
+
+static void irq_workd_setup(unsigned int cpu)
+{
+	sched_set_fifo_low(current);
+}
+
+static struct smp_hotplug_thread irqwork_threads = {
+	.store                  = &irq_workd,
+	.setup			= irq_workd_setup,
+	.thread_should_run      = irq_workd_should_run,
+	.thread_fn              = run_irq_workd,
+	.thread_comm            = "irq_work/%u",
+};
+
+static __init int irq_work_init_threads(void)
+{
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		BUG_ON(smpboot_register_percpu_thread(&irqwork_threads));
+	return 0;
+}
+early_initcall(irq_work_init_threads);
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 3260a65a9def6..12c53ac221ed1 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -88,6 +88,7 @@ static struct list_head kcov_remote_areas = LIST_HEAD_INIT(kcov_remote_areas);
 
 struct kcov_percpu_data {
 	void			*irq_area;
+	local_lock_t		lock;
 
 	unsigned int		saved_mode;
 	unsigned int		saved_size;
@@ -96,7 +97,9 @@ struct kcov_percpu_data {
 	int			saved_sequence;
 };
 
-static DEFINE_PER_CPU(struct kcov_percpu_data, kcov_percpu_data);
+static DEFINE_PER_CPU(struct kcov_percpu_data, kcov_percpu_data) = {
+	.lock = INIT_LOCAL_LOCK(lock),
+};
 
 /* Must be called with kcov_remote_lock locked. */
 static struct kcov_remote *kcov_remote_find(u64 handle)
@@ -834,7 +837,7 @@ void kcov_remote_start(u64 handle)
 	if (!in_task() && !in_softirq_really())
 		return;
 
-	local_irq_save(flags);
+	local_lock_irqsave(&kcov_percpu_data.lock, flags);
 
 	/*
 	 * Check that kcov_remote_start() is not called twice in background
@@ -842,7 +845,7 @@ void kcov_remote_start(u64 handle)
 	 */
 	mode = READ_ONCE(t->kcov_mode);
 	if (WARN_ON(in_task() && kcov_mode_enabled(mode))) {
-		local_irq_restore(flags);
+		local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 		return;
 	}
 	/*
@@ -851,14 +854,15 @@ void kcov_remote_start(u64 handle)
 	 * happened while collecting coverage from a background thread.
 	 */
 	if (WARN_ON(in_serving_softirq() && t->kcov_softirq)) {
-		local_irq_restore(flags);
+		local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 		return;
 	}
 
 	spin_lock(&kcov_remote_lock);
 	remote = kcov_remote_find(handle);
 	if (!remote) {
-		spin_unlock_irqrestore(&kcov_remote_lock, flags);
+		spin_unlock(&kcov_remote_lock);
+		local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 		return;
 	}
 	kcov_debug("handle = %llx, context: %s\n", handle,
@@ -879,19 +883,19 @@ void kcov_remote_start(u64 handle)
 		size = CONFIG_KCOV_IRQ_AREA_SIZE;
 		area = this_cpu_ptr(&kcov_percpu_data)->irq_area;
 	}
-	spin_unlock_irqrestore(&kcov_remote_lock, flags);
+	spin_unlock(&kcov_remote_lock);
 
 	/* Can only happen when in_task(). */
 	if (!area) {
+		local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 		area = vmalloc(size * sizeof(unsigned long));
 		if (!area) {
 			kcov_put(kcov);
 			return;
 		}
+		local_lock_irqsave(&kcov_percpu_data.lock, flags);
 	}
 
-	local_irq_save(flags);
-
 	/* Reset coverage size. */
 	*(u64 *)area = 0;
 
@@ -901,7 +905,7 @@ void kcov_remote_start(u64 handle)
 	}
 	kcov_start(t, kcov, size, area, mode, sequence);
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 
 }
 EXPORT_SYMBOL(kcov_remote_start);
@@ -975,12 +979,12 @@ void kcov_remote_stop(void)
 	if (!in_task() && !in_softirq_really())
 		return;
 
-	local_irq_save(flags);
+	local_lock_irqsave(&kcov_percpu_data.lock, flags);
 
 	mode = READ_ONCE(t->kcov_mode);
 	barrier();
 	if (!kcov_mode_enabled(mode)) {
-		local_irq_restore(flags);
+		local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 		return;
 	}
 	/*
@@ -988,12 +992,12 @@ void kcov_remote_stop(void)
 	 * actually found the remote handle and started collecting coverage.
 	 */
 	if (in_serving_softirq() && !t->kcov_softirq) {
-		local_irq_restore(flags);
+		local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 		return;
 	}
 	/* Make sure that kcov_softirq is only set when in softirq. */
 	if (WARN_ON(!in_serving_softirq() && t->kcov_softirq)) {
-		local_irq_restore(flags);
+		local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 		return;
 	}
 
@@ -1023,7 +1027,7 @@ void kcov_remote_stop(void)
 		spin_unlock(&kcov_remote_lock);
 	}
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(&kcov_percpu_data.lock, flags);
 
 	/* Get in kcov_remote_start(). */
 	kcov_put(kcov);
@@ -1044,8 +1048,8 @@ static int __init kcov_init(void)
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
-		void *area = vmalloc(CONFIG_KCOV_IRQ_AREA_SIZE *
-				sizeof(unsigned long));
+		void *area = vmalloc_node(CONFIG_KCOV_IRQ_AREA_SIZE *
+				sizeof(unsigned long), cpu_to_node(cpu));
 		if (!area)
 			return -ENOMEM;
 		per_cpu_ptr(&kcov_percpu_data, cpu)->irq_area = area;
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 0d463859ad329..561593f13df6a 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1245,10 +1245,10 @@ void kprobe_busy_end(void)
 }
 
 /*
- * This function is called from finish_task_switch when task tk becomes dead,
- * so that we can recycle any function-return probe instances associated
- * with this task. These left over instances represent probed functions
- * that have been called but will never return.
+ * This function is called from delayed_put_task_struct() when a task is
+ * dead and cleaned up to recycle any function-return probe instances
+ * associated with this task. These left over instances represent probed
+ * functions that have been called but will never return.
  */
 void kprobe_flush_task(struct task_struct *tk)
 {
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index e20c19e3ba49c..777168d58f02e 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -143,6 +143,15 @@ KERNEL_ATTR_RO(vmcoreinfo);
 
 #endif /* CONFIG_CRASH_CORE */
 
+#if defined(CONFIG_PREEMPT_RT)
+static ssize_t realtime_show(struct kobject *kobj,
+			     struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", 1);
+}
+KERNEL_ATTR_RO(realtime);
+#endif
+
 /* whether file capabilities are enabled */
 static ssize_t fscaps_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
@@ -233,6 +242,9 @@ static struct attribute * kernel_attrs[] = {
 #ifndef CONFIG_TINY_RCU
 	&rcu_expedited_attr.attr,
 	&rcu_normal_attr.attr,
+#endif
+#ifdef CONFIG_PREEMPT_RT
+	&realtime_attr.attr,
 #endif
 	NULL
 };
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 51e5a4891b244..5522b5d37951e 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -285,6 +285,7 @@ void __noreturn kthread_exit(long result)
 
 static int kthread(void *_create)
 {
+	static const struct sched_param param = { .sched_priority = 0 };
 	/* Copy data: it's on kthread's stack */
 	struct kthread_create_info *create = _create;
 	int (*threadfn)(void *data) = create->threadfn;
@@ -315,6 +316,13 @@ static int kthread(void *_create)
 	init_completion(&self->parked);
 	current->vfork_done = &self->exited;
 
+	/*
+	 * The new thread inherited kthreadd's priority and CPU mask. Reset
+	 * back to default in case they have been changed.
+	 */
+	sched_setscheduler_nocheck(current, SCHED_NORMAL, &param);
+	set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_KTHREAD));
+
 	/* OK, tell user we're spawned, wait for stop or wakeup */
 	__set_current_state(TASK_UNINTERRUPTIBLE);
 	create->result = current;
@@ -412,7 +420,6 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
 	}
 	task = create->result;
 	if (!IS_ERR(task)) {
-		static const struct sched_param param = { .sched_priority = 0 };
 		char name[TASK_COMM_LEN];
 
 		/*
@@ -421,13 +428,6 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
 		 */
 		vsnprintf(name, sizeof(name), namefmt, args);
 		set_task_comm(task, name);
-		/*
-		 * root may have changed our (kthreadd's) priority or CPU mask.
-		 * The kernel thread should not inherit these properties.
-		 */
-		sched_setscheduler_nocheck(task, SCHED_NORMAL, &param);
-		set_cpus_allowed_ptr(task,
-				     housekeeping_cpumask(HK_FLAG_KTHREAD));
 	}
 	kfree(create);
 	return task;
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 1f00d46ffd4da..a789c96b6be19 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2208,6 +2208,9 @@ static inline bool usage_match(struct lock_list *entry, void *mask)
 
 static inline bool usage_skip(struct lock_list *entry, void *mask)
 {
+	if (entry->class->lock_type == LD_LOCK_NORMAL)
+		return false;
+
 	/*
 	 * Skip local_lock() for irq inversion detection.
 	 *
@@ -2234,14 +2237,16 @@ static inline bool usage_skip(struct lock_list *entry, void *mask)
 	 * As a result, we will skip local_lock(), when we search for irq
 	 * inversion bugs.
 	 */
-	if (entry->class->lock_type == LD_LOCK_PERCPU) {
-		if (DEBUG_LOCKS_WARN_ON(entry->class->wait_type_inner < LD_WAIT_CONFIG))
-			return false;
+	if (entry->class->lock_type == LD_LOCK_PERCPU &&
+	    DEBUG_LOCKS_WARN_ON(entry->class->wait_type_inner < LD_WAIT_CONFIG))
+		return false;
 
-		return true;
-	}
+	/*
+	 * Skip WAIT_OVERRIDE for irq inversion detection -- it's not actually
+	 * a lock and only used to override the wait_type.
+	 */
 
-	return false;
+	return true;
 }
 
 /*
@@ -4708,7 +4713,8 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
 
 	for (; depth < curr->lockdep_depth; depth++) {
 		struct held_lock *prev = curr->held_locks + depth;
-		u8 prev_inner = hlock_class(prev)->wait_type_inner;
+		struct lock_class *class = hlock_class(prev);
+		u8 prev_inner = class->wait_type_inner;
 
 		if (prev_inner) {
 			/*
@@ -4718,6 +4724,14 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
 			 * Also due to trylocks.
 			 */
 			curr_inner = min(curr_inner, prev_inner);
+
+			/*
+			 * Allow override for annotations -- this is typically
+			 * only valid/needed for code that only exists when
+			 * CONFIG_PREEMPT_RT=n.
+			 */
+			if (unlikely(class->lock_type == LD_LOCK_WAIT_OVERRIDE))
+				curr_inner = prev_inner;
 		}
 	}
 
@@ -5471,6 +5485,7 @@ static noinstr void check_flags(unsigned long flags)
 		}
 	}
 
+#ifndef CONFIG_PREEMPT_RT
 	/*
 	 * We dont accurately track softirq state in e.g.
 	 * hardirq contexts (such as on 4KSTACKS), so only
@@ -5485,6 +5500,7 @@ static noinstr void check_flags(unsigned long flags)
 			DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
 		}
 	}
+#endif
 
 	if (!debug_locks)
 		print_irqtrace_events(current);
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 2118f8928eb7c..72a416caac45c 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1190,8 +1190,26 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock,
 	 * which is wrong, as the other waiter is not in a deadlock
 	 * situation.
 	 */
-	if (owner == task)
+	if (owner == task) {
+#if defined(DEBUG_WW_MUTEXES) && defined(CONFIG_DEBUG_LOCKING_API_SELFTESTS)
+		/*
+		 * The lockdep selftest for ww-mutex assumes in a few cases
+		 * the ww_ctx->contending_lock assignment via
+		 * __ww_mutex_check_kill() which does not happen if the rtmutex
+		 * detects the deadlock early.
+		 */
+		if (build_ww_mutex() && ww_ctx) {
+			struct rt_mutex *rtm;
+
+			/* Check whether the waiter should backout immediately */
+			rtm = container_of(lock, struct rt_mutex, rtmutex);
+
+			__ww_mutex_add_waiter(waiter, rtm, ww_ctx);
+			__ww_mutex_check_kill(rtm, waiter, ww_ctx);
+		}
+#endif
 		return -EDEADLK;
+	}
 
 	raw_spin_lock(&task->pi_lock);
 	waiter->task = task;
diff --git a/kernel/locking/rtmutex_api.c b/kernel/locking/rtmutex_api.c
index c4e191340c59b..06c3db9f6cf1c 100644
--- a/kernel/locking/rtmutex_api.c
+++ b/kernel/locking/rtmutex_api.c
@@ -21,12 +21,13 @@ int max_lock_depth = 1024;
  */
 static __always_inline int __rt_mutex_lock_common(struct rt_mutex *lock,
 						  unsigned int state,
+						  struct lockdep_map *nest_lock,
 						  unsigned int subclass)
 {
 	int ret;
 
 	might_sleep();
-	mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+	mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, _RET_IP_);
 	ret = __rt_mutex_lock(&lock->rtmutex, state);
 	if (ret)
 		mutex_release(&lock->dep_map, _RET_IP_);
@@ -48,10 +49,16 @@ EXPORT_SYMBOL(rt_mutex_base_init);
  */
 void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass)
 {
-	__rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass);
+	__rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, NULL, subclass);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
 
+void __sched _rt_mutex_lock_nest_lock(struct rt_mutex *lock, struct lockdep_map *nest_lock)
+{
+	__rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, nest_lock, 0);
+}
+EXPORT_SYMBOL_GPL(_rt_mutex_lock_nest_lock);
+
 #else /* !CONFIG_DEBUG_LOCK_ALLOC */
 
 /**
@@ -61,7 +68,7 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
  */
 void __sched rt_mutex_lock(struct rt_mutex *lock)
 {
-	__rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0);
+	__rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, NULL, 0);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_lock);
 #endif
@@ -77,10 +84,25 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock);
  */
 int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
 {
-	return __rt_mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0);
+	return __rt_mutex_lock_common(lock, TASK_INTERRUPTIBLE, NULL, 0);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
 
+/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock:		the rt_mutex to be locked
+ *
+ * Returns:
+ *  0		on success
+ * -EINTR	when interrupted by a signal
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+	return __rt_mutex_lock_common(lock, TASK_KILLABLE, NULL, 0);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
 /**
  * rt_mutex_trylock - try to lock a rt_mutex
  *
diff --git a/kernel/locking/rwbase_rt.c b/kernel/locking/rwbase_rt.c
index 88191f6e252c3..a28148a053838 100644
--- a/kernel/locking/rwbase_rt.c
+++ b/kernel/locking/rwbase_rt.c
@@ -73,15 +73,6 @@ static int __sched __rwbase_read_lock(struct rwbase_rt *rwb,
 	int ret;
 
 	raw_spin_lock_irq(&rtm->wait_lock);
-	/*
-	 * Allow readers, as long as the writer has not completely
-	 * acquired the semaphore for write.
-	 */
-	if (atomic_read(&rwb->readers) != WRITER_BIAS) {
-		atomic_inc(&rwb->readers);
-		raw_spin_unlock_irq(&rtm->wait_lock);
-		return 0;
-	}
 
 	/*
 	 * Call into the slow lock path with the rtmutex->wait_lock
diff --git a/kernel/locking/spinlock_rt.c b/kernel/locking/spinlock_rt.c
index d2912e44d61fd..9e396a09fe0fd 100644
--- a/kernel/locking/spinlock_rt.c
+++ b/kernel/locking/spinlock_rt.c
@@ -24,6 +24,17 @@
 #define RT_MUTEX_BUILD_SPINLOCKS
 #include "rtmutex.c"
 
+/*
+ * __might_resched() skips the state check as rtlocks are state
+ * preserving. Take RCU nesting into account as spin/read/write_lock() can
+ * legitimately nest into an RCU read side critical section.
+ */
+#define RTLOCK_RESCHED_OFFSETS						\
+	(rcu_preempt_depth() << MIGHT_RESCHED_RCU_SHIFT)
+
+#define rtlock_might_resched()						\
+	__might_resched(__FILE__, __LINE__, RTLOCK_RESCHED_OFFSETS)
+
 static __always_inline void rtlock_lock(struct rt_mutex_base *rtm)
 {
 	if (unlikely(!rt_mutex_cmpxchg_acquire(rtm, NULL, current)))
@@ -32,7 +43,7 @@ static __always_inline void rtlock_lock(struct rt_mutex_base *rtm)
 
 static __always_inline void __rt_spin_lock(spinlock_t *lock)
 {
-	___might_sleep(__FILE__, __LINE__, 0);
+	rtlock_might_resched();
 	rtlock_lock(&lock->lock);
 	rcu_read_lock();
 	migrate_disable();
@@ -210,7 +221,7 @@ EXPORT_SYMBOL(rt_write_trylock);
 
 void __sched rt_read_lock(rwlock_t *rwlock)
 {
-	___might_sleep(__FILE__, __LINE__, 0);
+	rtlock_might_resched();
 	rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);
 	rwbase_read_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);
 	rcu_read_lock();
@@ -220,7 +231,7 @@ EXPORT_SYMBOL(rt_read_lock);
 
 void __sched rt_write_lock(rwlock_t *rwlock)
 {
-	___might_sleep(__FILE__, __LINE__, 0);
+	rtlock_might_resched();
 	rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
 	rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);
 	rcu_read_lock();
@@ -246,12 +257,6 @@ void __sched rt_write_unlock(rwlock_t *rwlock)
 }
 EXPORT_SYMBOL(rt_write_unlock);
 
-int __sched rt_rwlock_is_contended(rwlock_t *rwlock)
-{
-	return rw_base_is_contended(&rwlock->rwbase);
-}
-EXPORT_SYMBOL(rt_rwlock_is_contended);
-
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 void __rt_rwlock_init(rwlock_t *rwlock, const char *name,
 		      struct lock_class_key *key)
diff --git a/kernel/panic.c b/kernel/panic.c
index 3b14c6d123ddc..d23124b1a0dff 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -245,12 +245,27 @@ void check_panic_on_warn(const char *origin)
 void panic(const char *fmt, ...)
 {
 	static char buf[1024];
+	va_list args2;
 	va_list args;
 	long i, i_next = 0, len;
 	int state = 0;
 	int old_cpu, this_cpu;
 	bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
 
+	console_verbose();
+	pr_emerg("Kernel panic - not syncing:\n");
+	va_start(args2, fmt);
+	va_copy(args, args2);
+	vprintk(fmt, args2);
+	va_end(args2);
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+	/*
+	 * Avoid nested stack-dumping if a panic occurs during oops processing
+	 */
+	if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
+		dump_stack();
+#endif
+	pr_flush(1000, true);
 	if (panic_on_warn) {
 		/*
 		 * This thread may hit another WARN() in the panic path.
@@ -291,24 +306,13 @@ void panic(const char *fmt, ...)
 	if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
 		panic_smp_self_stop();
 
-	console_verbose();
 	bust_spinlocks(1);
-	va_start(args, fmt);
 	len = vscnprintf(buf, sizeof(buf), fmt, args);
 	va_end(args);
 
 	if (len && buf[len - 1] == '\n')
 		buf[len - 1] = '\0';
 
-	pr_emerg("Kernel panic - not syncing: %s\n", buf);
-#ifdef CONFIG_DEBUG_BUGVERBOSE
-	/*
-	 * Avoid nested stack-dumping if a panic occurs during oops processing
-	 */
-	if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
-		dump_stack();
-#endif
-
 	/*
 	 * If kgdb is enabled, give it a chance to run before we stop all
 	 * the other CPUs or else we won't be able to debug processes left
@@ -625,9 +629,11 @@ static u64 oops_id;
 
 static int init_oops_id(void)
 {
+#ifndef CONFIG_PREEMPT_RT
 	if (!oops_id)
 		get_random_bytes(&oops_id, sizeof(oops_id));
 	else
+#endif
 		oops_id++;
 
 	return 0;
@@ -638,6 +644,7 @@ static void print_oops_end_marker(void)
 {
 	init_oops_id();
 	pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
+	pr_flush(1000, true);
 }
 
 /*
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 113990f38436e..3158d954459c1 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -44,6 +44,9 @@
 #include <linux/irq_work.h>
 #include <linux/ctype.h>
 #include <linux/uio.h>
+#include <linux/kgdb.h>
+#include <linux/kthread.h>
+#include <linux/clocksource.h>
 #include <linux/sched/clock.h>
 #include <linux/sched/debug.h>
 #include <linux/sched/task_stack.h>
@@ -268,11 +271,6 @@ static void __up_console_sem(unsigned long ip)
  */
 static int console_locked, console_suspended;
 
-/*
- * If exclusive_console is non-NULL then only this console is to be printed to.
- */
-static struct console *exclusive_console;
-
 /*
  *	Array of consoles built from command line options (console=)
  */
@@ -352,10 +350,13 @@ static int console_msg_format = MSG_FORMAT_DEFAULT;
  * non-prinatable characters are escaped in the "\xff" notation.
  */
 
+#ifdef CONFIG_PRINTK
 /* syslog_lock protects syslog_* variables and write access to clear_seq. */
 static DEFINE_MUTEX(syslog_lock);
 
-#ifdef CONFIG_PRINTK
+/* Set to enable sync mode. Once set, it is never cleared. */
+static bool sync_mode;
+
 DECLARE_WAIT_QUEUE_HEAD(log_wait);
 /* All 3 protected by @syslog_lock. */
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
@@ -363,17 +364,6 @@ static u64 syslog_seq;
 static size_t syslog_partial;
 static bool syslog_time;
 
-/* All 3 protected by @console_sem. */
-/* the next printk record to write to the console */
-static u64 console_seq;
-static u64 exclusive_console_stop_seq;
-static unsigned long console_dropped;
-
-struct latched_seq {
-	seqcount_latch_t	latch;
-	u64			val[2];
-};
-
 /*
  * The next printk record to read after the last 'clear' command. There are
  * two copies (updated with seqcount_latch) so that reads can locklessly
@@ -391,9 +381,6 @@ static struct latched_seq clear_seq = {
 #define PREFIX_MAX		32
 #endif
 
-/* the maximum size of a formatted record (i.e. with prefix added per line) */
-#define CONSOLE_LOG_MAX		1024
-
 /* the maximum size allowed to be reserved for a record */
 #define LOG_LINE_MAX		(CONSOLE_LOG_MAX - PREFIX_MAX)
 
@@ -437,7 +424,7 @@ bool printk_percpu_data_ready(void)
 	return __printk_percpu_data_ready;
 }
 
-/* Must be called under syslog_lock. */
+/* Must be called under associated write-protection lock. */
 static void latched_seq_write(struct latched_seq *ls, u64 val)
 {
 	raw_write_seqcount_latch(&ls->latch);
@@ -1771,194 +1758,152 @@ SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
 	return do_syslog(type, buf, len, SYSLOG_FROM_READER);
 }
 
-/*
- * Special console_lock variants that help to reduce the risk of soft-lockups.
- * They allow to pass console_lock to another printk() call using a busy wait.
- */
+int printk_delay_msec __read_mostly;
 
-#ifdef CONFIG_LOCKDEP
-static struct lockdep_map console_owner_dep_map = {
-	.name = "console_owner"
-};
-#endif
+static inline void printk_delay(int level)
+{
+	boot_delay_msec(level);
 
-static DEFINE_RAW_SPINLOCK(console_owner_lock);
-static struct task_struct *console_owner;
-static bool console_waiter;
+	if (unlikely(printk_delay_msec)) {
+		int m = printk_delay_msec;
 
-/**
- * console_lock_spinning_enable - mark beginning of code where another
- *	thread might safely busy wait
- *
- * This basically converts console_lock into a spinlock. This marks
- * the section where the console_lock owner can not sleep, because
- * there may be a waiter spinning (like a spinlock). Also it must be
- * ready to hand over the lock at the end of the section.
- */
-static void console_lock_spinning_enable(void)
+		while (m--) {
+			mdelay(1);
+			touch_nmi_watchdog();
+		}
+	}
+}
+
+static bool kernel_sync_mode(void)
 {
-	raw_spin_lock(&console_owner_lock);
-	console_owner = current;
-	raw_spin_unlock(&console_owner_lock);
+	return (oops_in_progress || sync_mode);
+}
 
-	/* The waiter may spin on us after setting console_owner */
-	spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_);
+static bool console_may_sync(struct console *con)
+{
+	if (!(con->flags & CON_ENABLED))
+		return false;
+	if (con->write_atomic && kernel_sync_mode())
+		return true;
+	if (con->write_atomic && (con->flags & CON_HANDOVER) && !con->thread)
+		return true;
+	if (con->write && (con->flags & CON_BOOT) && !con->thread)
+		return true;
+	return false;
 }
 
-/**
- * console_lock_spinning_disable_and_check - mark end of code where another
- *	thread was able to busy wait and check if there is a waiter
- *
- * This is called at the end of the section where spinning is allowed.
- * It has two functions. First, it is a signal that it is no longer
- * safe to start busy waiting for the lock. Second, it checks if
- * there is a busy waiter and passes the lock rights to her.
- *
- * Important: Callers lose the lock if there was a busy waiter.
- *	They must not touch items synchronized by console_lock
- *	in this case.
- *
- * Return: 1 if the lock rights were passed, 0 otherwise.
- */
-static int console_lock_spinning_disable_and_check(void)
+static bool call_sync_console_driver(struct console *con, const char *text, size_t text_len)
 {
-	int waiter;
+	if (!(con->flags & CON_ENABLED))
+		return false;
 
-	raw_spin_lock(&console_owner_lock);
-	waiter = READ_ONCE(console_waiter);
-	console_owner = NULL;
-	raw_spin_unlock(&console_owner_lock);
+	if (con->write_atomic && kernel_sync_mode()) {
+		con->write_atomic(con, text, text_len);
+		return true;
+	}
 
-	if (!waiter) {
-		spin_release(&console_owner_dep_map, _THIS_IP_);
-		return 0;
+	if (con->write_atomic && (con->flags & CON_HANDOVER) && !con->thread) {
+		if (console_trylock()) {
+			con->write_atomic(con, text, text_len);
+			console_unlock();
+			return true;
+		}
+
+	} else if (con->write && (con->flags & CON_BOOT) && !con->thread) {
+		if (console_trylock()) {
+			con->write(con, text, text_len);
+			console_unlock();
+			return true;
+		}
 	}
 
-	/* The waiter is now free to continue */
-	WRITE_ONCE(console_waiter, false);
+	return false;
+}
 
-	spin_release(&console_owner_dep_map, _THIS_IP_);
+static bool have_atomic_console(void)
+{
+	struct console *con;
 
-	/*
-	 * Hand off console_lock to waiter. The waiter will perform
-	 * the up(). After this, the waiter is the console_lock owner.
-	 */
-	mutex_release(&console_lock_dep_map, _THIS_IP_);
-	return 1;
+	for_each_console(con) {
+		if (!(con->flags & CON_ENABLED))
+			continue;
+		if (con->write_atomic)
+			return true;
+	}
+	return false;
 }
 
-/**
- * console_trylock_spinning - try to get console_lock by busy waiting
- *
- * This allows to busy wait for the console_lock when the current
- * owner is running in specially marked sections. It means that
- * the current owner is running and cannot reschedule until it
- * is ready to lose the lock.
- *
- * Return: 1 if we got the lock, 0 othrewise
- */
-static int console_trylock_spinning(void)
+static bool print_sync(struct console *con, u64 *seq)
 {
-	struct task_struct *owner = NULL;
-	bool waiter;
-	bool spin = false;
-	unsigned long flags;
+	struct printk_info info;
+	struct printk_record r;
+	size_t text_len;
 
-	if (console_trylock())
-		return 1;
+	prb_rec_init_rd(&r, &info, &con->sync_buf[0], sizeof(con->sync_buf));
 
-	printk_safe_enter_irqsave(flags);
+	if (!prb_read_valid(prb, *seq, &r))
+		return false;
 
-	raw_spin_lock(&console_owner_lock);
-	owner = READ_ONCE(console_owner);
-	waiter = READ_ONCE(console_waiter);
-	if (!waiter && owner && owner != current) {
-		WRITE_ONCE(console_waiter, true);
-		spin = true;
-	}
-	raw_spin_unlock(&console_owner_lock);
+	text_len = record_print_text(&r, console_msg_format & MSG_FORMAT_SYSLOG, printk_time);
 
-	/*
-	 * If there is an active printk() writing to the
-	 * consoles, instead of having it write our data too,
-	 * see if we can offload that load from the active
-	 * printer, and do some printing ourselves.
-	 * Go into a spin only if there isn't already a waiter
-	 * spinning, and there is an active printer, and
-	 * that active printer isn't us (recursive printk?).
-	 */
-	if (!spin) {
-		printk_safe_exit_irqrestore(flags);
-		return 0;
-	}
+	if (!call_sync_console_driver(con, &con->sync_buf[0], text_len))
+		return false;
 
-	/* We spin waiting for the owner to release us */
-	spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_);
-	/* Owner will clear console_waiter on hand off */
-	while (READ_ONCE(console_waiter))
-		cpu_relax();
-	spin_release(&console_owner_dep_map, _THIS_IP_);
+	*seq = r.info->seq;
 
-	printk_safe_exit_irqrestore(flags);
-	/*
-	 * The owner passed the console lock to us.
-	 * Since we did not spin on console lock, annotate
-	 * this as a trylock. Otherwise lockdep will
-	 * complain.
-	 */
-	mutex_acquire(&console_lock_dep_map, 0, 1, _THIS_IP_);
+	touch_softlockup_watchdog_sync();
+	clocksource_touch_watchdog();
+	rcu_cpu_stall_reset();
+	touch_nmi_watchdog();
 
-	/*
-	 * Update @console_may_schedule for trylock because the previous
-	 * owner may have been schedulable.
-	 */
-	console_may_schedule = 0;
+	if (text_len)
+		printk_delay(r.info->level);
 
-	return 1;
+	return true;
 }
 
-/*
- * Call the console drivers, asking them to write out
- * log_buf[start] to log_buf[end - 1].
- * The console_lock must be held.
- */
-static void call_console_drivers(const char *ext_text, size_t ext_len,
-				 const char *text, size_t len)
+static u64 read_console_seq(struct console *con)
 {
-	static char dropped_text[64];
-	size_t dropped_len = 0;
-	struct console *con;
+	u64 seq2;
+	u64 seq;
 
-	trace_console_rcuidle(text, len);
+	seq = latched_seq_read_nolock(&con->printk_seq);
+	seq2 = latched_seq_read_nolock(&con->printk_sync_seq);
+	if (seq2 > seq)
+		seq = seq2;
+#ifdef CONFIG_HAVE_NMI
+	seq2 = latched_seq_read_nolock(&con->printk_sync_nmi_seq);
+	if (seq2 > seq)
+		seq = seq2;
+#endif
+	return seq;
+}
 
-	if (!console_drivers)
-		return;
+static void print_sync_until(struct console *con, u64 seq, bool is_locked)
+{
+	u64 printk_seq;
 
-	if (console_dropped) {
-		dropped_len = snprintf(dropped_text, sizeof(dropped_text),
-				       "** %lu printk messages dropped **\n",
-				       console_dropped);
-		console_dropped = 0;
-	}
+	while (!__printk_cpu_trylock())
+		cpu_relax();
 
-	for_each_console(con) {
-		if (exclusive_console && con != exclusive_console)
-			continue;
-		if (!(con->flags & CON_ENABLED))
-			continue;
-		if (!con->write)
-			continue;
-		if (!cpu_online(smp_processor_id()) &&
-		    !(con->flags & CON_ANYTIME))
-			continue;
-		if (con->flags & CON_EXTENDED)
-			con->write(con, ext_text, ext_len);
-		else {
-			if (dropped_len)
-				con->write(con, dropped_text, dropped_len);
-			con->write(con, text, len);
-		}
+	for (;;) {
+		printk_seq = read_console_seq(con);
+		if (printk_seq >= seq)
+			break;
+		if (!print_sync(con, &printk_seq))
+			break;
+
+		if (is_locked)
+			latched_seq_write(&con->printk_seq, printk_seq + 1);
+#ifdef CONFIG_PRINTK_NMI
+		else if (in_nmi())
+			latched_seq_write(&con->printk_sync_nmi_seq, printk_seq + 1);
+#endif
+		else
+			latched_seq_write(&con->printk_sync_seq, printk_seq + 1);
 	}
+
+	__printk_cpu_unlock();
 }
 
 /*
@@ -2031,20 +1976,6 @@ static u8 *__printk_recursion_counter(void)
 		local_irq_restore(flags);		\
 	} while (0)
 
-int printk_delay_msec __read_mostly;
-
-static inline void printk_delay(void)
-{
-	if (unlikely(printk_delay_msec)) {
-		int m = printk_delay_msec;
-
-		while (m--) {
-			mdelay(1);
-			touch_nmi_watchdog();
-		}
-	}
-}
-
 static inline u32 printk_caller_id(void)
 {
 	return in_task() ? task_pid_nr(current) :
@@ -2132,6 +2063,7 @@ int vprintk_store(int facility, int level,
 	const u32 caller_id = printk_caller_id();
 	struct prb_reserved_entry e;
 	enum printk_info_flags flags = 0;
+	bool final_commit = false;
 	struct printk_record r;
 	unsigned long irqflags;
 	u16 trunc_msg_len = 0;
@@ -2142,6 +2074,7 @@ int vprintk_store(int facility, int level,
 	u16 text_len;
 	int ret = 0;
 	u64 ts_nsec;
+	u64 seq;
 
 	/*
 	 * Since the duration of printk() can vary depending on the message
@@ -2180,6 +2113,7 @@ int vprintk_store(int facility, int level,
 	if (flags & LOG_CONT) {
 		prb_rec_init_wr(&r, reserve_size);
 		if (prb_reserve_in_last(&e, prb, &r, caller_id, LOG_LINE_MAX)) {
+			seq = r.info->seq;
 			text_len = printk_sprint(&r.text_buf[r.info->text_len], reserve_size,
 						 facility, &flags, fmt, args);
 			r.info->text_len += text_len;
@@ -2187,6 +2121,7 @@ int vprintk_store(int facility, int level,
 			if (flags & LOG_NEWLINE) {
 				r.info->flags |= LOG_NEWLINE;
 				prb_final_commit(&e);
+				final_commit = true;
 			} else {
 				prb_commit(&e);
 			}
@@ -2210,6 +2145,7 @@ int vprintk_store(int facility, int level,
 		if (!prb_reserve(&e, prb, &r))
 			goto out;
 	}
+	seq = r.info->seq;
 
 	/* fill message */
 	text_len = printk_sprint(&r.text_buf[0], reserve_size, facility, &flags, fmt, args);
@@ -2225,13 +2161,25 @@ int vprintk_store(int facility, int level,
 		memcpy(&r.info->dev_info, dev_info, sizeof(r.info->dev_info));
 
 	/* A message without a trailing newline can be continued. */
-	if (!(flags & LOG_NEWLINE))
+	if (!(flags & LOG_NEWLINE)) {
 		prb_commit(&e);
-	else
+	} else {
 		prb_final_commit(&e);
+		final_commit = true;
+	}
 
 	ret = text_len + trunc_msg_len;
 out:
+	/* only the kernel may perform synchronous printing */
+	if (facility == 0 && final_commit) {
+		struct console *con;
+
+		for_each_console(con) {
+			if (console_may_sync(con))
+				print_sync_until(con, seq + 1, false);
+		}
+	}
+
 	printk_exit_irqrestore(recursion_ptr, irqflags);
 	return ret;
 }
@@ -2241,45 +2189,17 @@ asmlinkage int vprintk_emit(int facility, int level,
 			    const char *fmt, va_list args)
 {
 	int printed_len;
-	bool in_sched = false;
 
 	/* Suppress unimportant messages after panic happens */
 	if (unlikely(suppress_printk))
 		return 0;
 
-	if (level == LOGLEVEL_SCHED) {
+	if (level == LOGLEVEL_SCHED)
 		level = LOGLEVEL_DEFAULT;
-		in_sched = true;
-	}
-
-	boot_delay_msec(level);
-	printk_delay();
 
 	printed_len = vprintk_store(facility, level, dev_info, fmt, args);
 
-	/* If called from the scheduler, we can not call up(). */
-	if (!in_sched) {
-		/*
-		 * Disable preemption to avoid being preempted while holding
-		 * console_sem which would prevent anyone from printing to
-		 * console
-		 */
-		preempt_disable();
-		/*
-		 * Try to acquire and then immediately release the console
-		 * semaphore.  The release will print out buffers and wake up
-		 * /dev/kmsg and syslog() users.
-		 */
-		if (console_trylock_spinning())
-			console_unlock();
-		preempt_enable();
-	}
-
-	if (in_sched)
-		defer_console_output();
-	else
-		wake_up_klogd();
-
+	wake_up_klogd();
 	return printed_len;
 }
 EXPORT_SYMBOL(vprintk_emit);
@@ -2303,37 +2223,166 @@ asmlinkage __visible int _printk(const char *fmt, ...)
 }
 EXPORT_SYMBOL(_printk);
 
-#else /* CONFIG_PRINTK */
+static int printk_kthread_func(void *data)
+{
+	struct console *con = data;
+	unsigned long dropped = 0;
+	char *dropped_text = NULL;
+	struct printk_info info;
+	struct printk_record r;
+	char *ext_text = NULL;
+	size_t dropped_len;
+	int ret = -ENOMEM;
+	char *text = NULL;
+	char *write_text;
+	size_t len;
+	int error;
+	u64 seq;
 
-#define CONSOLE_LOG_MAX		0
-#define printk_time		false
+	if (con->flags & CON_EXTENDED) {
+		ext_text = kmalloc(CONSOLE_EXT_LOG_MAX, GFP_KERNEL);
+		if (!ext_text)
+			goto out;
+	}
+	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+	dropped_text = kmalloc(64, GFP_KERNEL);
+	if (!text || !dropped_text)
+		goto out;
+	if (con->flags & CON_EXTENDED)
+		write_text = ext_text;
+	else
+		write_text = text;
 
-#define prb_read_valid(rb, seq, r)	false
-#define prb_first_valid_seq(rb)		0
+	seq = read_console_seq(con);
 
-static u64 syslog_seq;
-static u64 console_seq;
-static u64 exclusive_console_stop_seq;
-static unsigned long console_dropped;
+	prb_rec_init_rd(&r, &info, text, LOG_LINE_MAX + PREFIX_MAX);
+
+	for (;;) {
+		error = wait_event_interruptible(log_wait,
+						 prb_read_valid(prb, seq, &r) || kthread_should_stop());
+
+		if (kthread_should_stop())
+			break;
+
+		if (error)
+			continue;
+
+		if (seq != r.info->seq) {
+			dropped += r.info->seq - seq;
+			seq = r.info->seq;
+		}
 
-static size_t record_print_text(const struct printk_record *r,
-				bool syslog, bool time)
+		seq++;
+
+		if (!(con->flags & CON_ENABLED))
+			continue;
+
+		if (suppress_message_printing(r.info->level))
+			continue;
+
+		if (con->flags & CON_EXTENDED) {
+			len = info_print_ext_header(ext_text,
+						    CONSOLE_EXT_LOG_MAX,
+						    r.info);
+			len += msg_print_ext_body(ext_text + len,
+						  CONSOLE_EXT_LOG_MAX - len,
+						  &r.text_buf[0], r.info->text_len,
+						  &r.info->dev_info);
+		} else {
+			len = record_print_text(&r,
+						console_msg_format & MSG_FORMAT_SYSLOG,
+						printk_time);
+		}
+
+		console_lock();
+
+		/*
+		 * Even though the printk kthread is always preemptible, it is
+		 * still not allowed to call cond_resched() from within
+		 * console drivers. The task may become non-preemptible in the
+		 * console driver call chain. For example, vt_console_print()
+		 * takes a spinlock and then can call into fbcon_redraw(),
+		 * which can conditionally invoke cond_resched().
+		 */
+		console_may_schedule = 0;
+
+		if (kernel_sync_mode() && con->write_atomic) {
+			console_unlock();
+			break;
+		}
+
+		if (!(con->flags & CON_EXTENDED) && dropped) {
+			dropped_len = snprintf(dropped_text, 64,
+					       "** %lu printk messages dropped **\n",
+					       dropped);
+			dropped = 0;
+
+			con->write(con, dropped_text, dropped_len);
+			printk_delay(r.info->level);
+		}
+
+		con->write(con, write_text, len);
+		if (len)
+			printk_delay(r.info->level);
+
+		latched_seq_write(&con->printk_seq, seq);
+
+		console_unlock();
+	}
+	ret = 0;
+out:
+	kfree(dropped_text);
+	kfree(text);
+	kfree(ext_text);
+	pr_info("%sconsole [%s%d]: printing thread stopped\n",
+		(con->flags & CON_BOOT) ? "boot" : "",
+		con->name, con->index);
+	return ret;
+}
+
+/* Must be called within console_lock(). */
+static void start_printk_kthread(struct console *con)
 {
-	return 0;
+	/* No need to start a printing thread if the console cannot print. */
+	if (!con->write)
+		return;
+
+	con->thread = kthread_run(printk_kthread_func, con,
+				  "pr/%s%d", con->name, con->index);
+	if (IS_ERR(con->thread)) {
+		pr_err("%sconsole [%s%d]: unable to start printing thread\n",
+		       (con->flags & CON_BOOT) ? "boot" : "",
+		       con->name, con->index);
+		return;
+	}
+	pr_info("%sconsole [%s%d]: printing thread started\n",
+		(con->flags & CON_BOOT) ? "boot" : "",
+		con->name, con->index);
 }
-static ssize_t info_print_ext_header(char *buf, size_t size,
-				     struct printk_info *info)
+
+/* protected by console_lock */
+static bool kthreads_started;
+
+/* Must be called within console_lock(). */
+static void console_try_thread(struct console *con)
 {
-	return 0;
+	if (kthreads_started) {
+		start_printk_kthread(con);
+		return;
+	}
+
+	/*
+	 * The printing threads have not been started yet. If this console
+	 * can print synchronously, print all unprinted messages.
+	 */
+	if (console_may_sync(con)) {
+		unsigned long flags;
+
+		local_irq_save(flags);
+		print_sync_until(con, prb_next_seq(prb), true);
+		local_irq_restore(flags);
+	}
 }
-static ssize_t msg_print_ext_body(char *buf, size_t size,
-				  char *text, size_t text_len,
-				  struct dev_printk_info *dev_info) { return 0; }
-static void console_lock_spinning_enable(void) { }
-static int console_lock_spinning_disable_and_check(void) { return 0; }
-static void call_console_drivers(const char *ext_text, size_t ext_len,
-				 const char *text, size_t len) {}
-static bool suppress_message_printing(int level) { return false; }
 
 #endif /* CONFIG_PRINTK */
 
@@ -2590,34 +2639,6 @@ int is_console_locked(void)
 }
 EXPORT_SYMBOL(is_console_locked);
 
-/*
- * Check if we have any console that is capable of printing while cpu is
- * booting or shutting down. Requires console_sem.
- */
-static int have_callable_console(void)
-{
-	struct console *con;
-
-	for_each_console(con)
-		if ((con->flags & CON_ENABLED) &&
-				(con->flags & CON_ANYTIME))
-			return 1;
-
-	return 0;
-}
-
-/*
- * Can we actually use the console at this time on this cpu?
- *
- * Console drivers may assume that per-cpu resources have been allocated. So
- * unless they're explicitly marked as being able to cope (CON_ANYTIME) don't
- * call them until this CPU is officially up.
- */
-static inline int can_use_console(void)
-{
-	return cpu_online(raw_smp_processor_id()) || have_callable_console();
-}
-
 /**
  * console_unlock - unlock the console system
  *
@@ -2634,140 +2655,13 @@ static inline int can_use_console(void)
  */
 void console_unlock(void)
 {
-	static char ext_text[CONSOLE_EXT_LOG_MAX];
-	static char text[CONSOLE_LOG_MAX];
-	unsigned long flags;
-	bool do_cond_resched, retry;
-	struct printk_info info;
-	struct printk_record r;
-	u64 __maybe_unused next_seq;
-
 	if (console_suspended) {
 		up_console_sem();
 		return;
 	}
 
-	prb_rec_init_rd(&r, &info, text, sizeof(text));
-
-	/*
-	 * Console drivers are called with interrupts disabled, so
-	 * @console_may_schedule should be cleared before; however, we may
-	 * end up dumping a lot of lines, for example, if called from
-	 * console registration path, and should invoke cond_resched()
-	 * between lines if allowable.  Not doing so can cause a very long
-	 * scheduling stall on a slow console leading to RCU stall and
-	 * softlockup warnings which exacerbate the issue with more
-	 * messages practically incapacitating the system.
-	 *
-	 * console_trylock() is not able to detect the preemptive
-	 * context reliably. Therefore the value must be stored before
-	 * and cleared after the "again" goto label.
-	 */
-	do_cond_resched = console_may_schedule;
-again:
-	console_may_schedule = 0;
-
-	/*
-	 * We released the console_sem lock, so we need to recheck if
-	 * cpu is online and (if not) is there at least one CON_ANYTIME
-	 * console.
-	 */
-	if (!can_use_console()) {
-		console_locked = 0;
-		up_console_sem();
-		return;
-	}
-
-	for (;;) {
-		size_t ext_len = 0;
-		int handover;
-		size_t len;
-
-skip:
-		if (!prb_read_valid(prb, console_seq, &r))
-			break;
-
-		if (console_seq != r.info->seq) {
-			console_dropped += r.info->seq - console_seq;
-			console_seq = r.info->seq;
-		}
-
-		if (suppress_message_printing(r.info->level)) {
-			/*
-			 * Skip record we have buffered and already printed
-			 * directly to the console when we received it, and
-			 * record that has level above the console loglevel.
-			 */
-			console_seq++;
-			goto skip;
-		}
-
-		/* Output to all consoles once old messages replayed. */
-		if (unlikely(exclusive_console &&
-			     console_seq >= exclusive_console_stop_seq)) {
-			exclusive_console = NULL;
-		}
-
-		/*
-		 * Handle extended console text first because later
-		 * record_print_text() will modify the record buffer in-place.
-		 */
-		if (nr_ext_console_drivers) {
-			ext_len = info_print_ext_header(ext_text,
-						sizeof(ext_text),
-						r.info);
-			ext_len += msg_print_ext_body(ext_text + ext_len,
-						sizeof(ext_text) - ext_len,
-						&r.text_buf[0],
-						r.info->text_len,
-						&r.info->dev_info);
-		}
-		len = record_print_text(&r,
-				console_msg_format & MSG_FORMAT_SYSLOG,
-				printk_time);
-		console_seq++;
-
-		/*
-		 * While actively printing out messages, if another printk()
-		 * were to occur on another CPU, it may wait for this one to
-		 * finish. This task can not be preempted if there is a
-		 * waiter waiting to take over.
-		 *
-		 * Interrupts are disabled because the hand over to a waiter
-		 * must not be interrupted until the hand over is completed
-		 * (@console_waiter is cleared).
-		 */
-		printk_safe_enter_irqsave(flags);
-		console_lock_spinning_enable();
-
-		stop_critical_timings();	/* don't trace print latency */
-		call_console_drivers(ext_text, ext_len, text, len);
-		start_critical_timings();
-
-		handover = console_lock_spinning_disable_and_check();
-		printk_safe_exit_irqrestore(flags);
-		if (handover)
-			return;
-
-		if (do_cond_resched)
-			cond_resched();
-	}
-
-	/* Get consistent value of the next-to-be-used sequence number. */
-	next_seq = console_seq;
-
 	console_locked = 0;
 	up_console_sem();
-
-	/*
-	 * Someone could have filled up the buffer again, so re-check if there's
-	 * something to flush. In case we cannot trylock the console_sem again,
-	 * there's a new owner and the console_unlock() from them will do the
-	 * flush, no worries.
-	 */
-	retry = prb_read_valid(prb, next_seq, NULL);
-	if (retry && console_trylock())
-		goto again;
 }
 EXPORT_SYMBOL(console_unlock);
 
@@ -2817,18 +2711,20 @@ void console_unblank(void)
  */
 void console_flush_on_panic(enum con_flush_mode mode)
 {
-	/*
-	 * If someone else is holding the console lock, trylock will fail
-	 * and may_schedule may be set.  Ignore and proceed to unlock so
-	 * that messages are flushed out.  As this can be called from any
-	 * context and we don't want to get preempted while flushing,
-	 * ensure may_schedule is cleared.
-	 */
-	console_trylock();
-	console_may_schedule = 0;
+	if (!console_trylock())
+		return;
+
+#ifdef CONFIG_PRINTK
+	if (mode == CONSOLE_REPLAY_ALL) {
+		struct console *c;
+		u64 seq;
+
+		seq = prb_first_valid_seq(prb);
+		for_each_console(c)
+			latched_seq_write(&c->printk_seq, seq);
+	}
+#endif
 
-	if (mode == CONSOLE_REPLAY_ALL)
-		console_seq = prb_first_valid_seq(prb);
 	console_unlock();
 }
 
@@ -2997,6 +2893,7 @@ static void try_enable_default_console(struct console *newcon)
 void register_console(struct console *newcon)
 {
 	struct console *bcon = NULL;
+	u64 __maybe_unused seq = 0;
 	int err;
 
 	for_each_console(bcon) {
@@ -3019,6 +2916,8 @@ void register_console(struct console *newcon)
 		}
 	}
 
+	newcon->thread = NULL;
+
 	if (console_drivers && console_drivers->flags & CON_BOOT)
 		bcon = console_drivers;
 
@@ -3050,8 +2949,10 @@ void register_console(struct console *newcon)
 	 * the real console are the same physical device, it's annoying to
 	 * see the beginning boot messages twice
 	 */
-	if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV))
+	if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV)) {
 		newcon->flags &= ~CON_PRINTBUFFER;
+		newcon->flags |= CON_HANDOVER;
+	}
 
 	/*
 	 *	Put this console in the list - keep the
@@ -3073,27 +2974,21 @@ void register_console(struct console *newcon)
 	if (newcon->flags & CON_EXTENDED)
 		nr_ext_console_drivers++;
 
-	if (newcon->flags & CON_PRINTBUFFER) {
-		/*
-		 * console_unlock(); will print out the buffered messages
-		 * for us.
-		 *
-		 * We're about to replay the log buffer.  Only do this to the
-		 * just-registered console to avoid excessive message spam to
-		 * the already-registered consoles.
-		 *
-		 * Set exclusive_console with disabled interrupts to reduce
-		 * race window with eventual console_flush_on_panic() that
-		 * ignores console_lock.
-		 */
-		exclusive_console = newcon;
-		exclusive_console_stop_seq = console_seq;
+#ifdef CONFIG_PRINTK
+	if (!(newcon->flags & CON_PRINTBUFFER))
+		seq = prb_next_seq(prb);
 
-		/* Get a consistent copy of @syslog_seq. */
-		mutex_lock(&syslog_lock);
-		console_seq = syslog_seq;
-		mutex_unlock(&syslog_lock);
-	}
+	seqcount_latch_init(&newcon->printk_seq.latch);
+	latched_seq_write(&newcon->printk_seq, seq);
+	seqcount_latch_init(&newcon->printk_sync_seq.latch);
+	latched_seq_write(&newcon->printk_sync_seq, seq);
+#ifdef CONFIG_HAVE_NMI
+	seqcount_latch_init(&newcon->printk_sync_nmi_seq.latch);
+	latched_seq_write(&newcon->printk_sync_nmi_seq, seq);
+#endif
+
+	console_try_thread(newcon);
+#endif /* CONFIG_PRINTK */
 	console_unlock();
 	console_sysfs_notify();
 
@@ -3167,6 +3062,9 @@ int unregister_console(struct console *console)
 	console_unlock();
 	console_sysfs_notify();
 
+	if (console->thread && !IS_ERR(console->thread))
+		kthread_stop(console->thread);
+
 	if (console->exit)
 		res = console->exit(console);
 
@@ -3249,6 +3147,15 @@ static int __init printk_late_init(void)
 			unregister_console(con);
 		}
 	}
+
+#ifdef CONFIG_PRINTK
+	console_lock();
+	for_each_console(con)
+		start_printk_kthread(con);
+	kthreads_started = true;
+	console_unlock();
+#endif
+
 	ret = cpuhp_setup_state_nocalls(CPUHP_PRINTK_DEAD, "printk:dead", NULL,
 					console_cpu_notify);
 	WARN_ON(ret < 0);
@@ -3272,14 +3179,8 @@ static void wake_up_klogd_work_func(struct irq_work *irq_work)
 {
 	int pending = this_cpu_xchg(printk_pending, 0);
 
-	if (pending & PRINTK_PENDING_OUTPUT) {
-		/* If trylock fails, someone else is doing the printing */
-		if (console_trylock())
-			console_unlock();
-	}
-
 	if (pending & PRINTK_PENDING_WAKEUP)
-		wake_up_interruptible(&log_wait);
+		wake_up_interruptible_all(&log_wait);
 }
 
 static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) =
@@ -3348,7 +3249,7 @@ void defer_console_output(void)
 
 void printk_trigger_flush(void)
 {
-	defer_console_output();
+	wake_up_klogd();
 }
 
 int vprintk_deferred(const char *fmt, va_list args)
@@ -3494,6 +3395,24 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 {
 	struct kmsg_dumper *dumper;
 
+	if (!oops_in_progress) {
+		/*
+		 * If atomic consoles are available, activate kernel sync mode
+		 * to make sure any final messages are visible. The trailing
+		 * printk message is important to flush any pending messages.
+		 */
+		if (have_atomic_console()) {
+			sync_mode = true;
+			pr_info("enabled sync mode\n");
+		}
+
+		/*
+		 * Give the printing threads time to flush, allowing up to
+		 * 1s of no printing forward progress before giving up.
+		 */
+		pr_flush(1000, true);
+	}
+
 	rcu_read_lock();
 	list_for_each_entry_rcu(dumper, &dump_list, list) {
 		enum kmsg_dump_reason max_reason = dumper->max_reason;
@@ -3676,6 +3595,7 @@ EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
 #ifdef CONFIG_SMP
 static atomic_t printk_cpulock_owner = ATOMIC_INIT(-1);
 static atomic_t printk_cpulock_nested = ATOMIC_INIT(0);
+static unsigned int kgdb_cpu = -1;
 
 /**
  * __printk_wait_on_cpu_lock() - Busy wait until the printk cpu-reentrant
@@ -3755,6 +3675,9 @@ EXPORT_SYMBOL(__printk_cpu_trylock);
  */
 void __printk_cpu_unlock(void)
 {
+	bool trigger_kgdb = false;
+	unsigned int cpu;
+
 	if (atomic_read(&printk_cpulock_nested)) {
 		atomic_dec(&printk_cpulock_nested);
 		return;
@@ -3765,6 +3688,12 @@ void __printk_cpu_unlock(void)
 	 * LMM(__printk_cpu_unlock:A)
 	 */
 
+	cpu = smp_processor_id();
+	if (kgdb_cpu == cpu) {
+		trigger_kgdb = true;
+		kgdb_cpu = -1;
+	}
+
 	/*
 	 * Guarantee loads and stores from this CPU when it was the
 	 * lock owner are visible to the next lock owner. This pairs
@@ -3785,6 +3714,100 @@ void __printk_cpu_unlock(void)
 	 */
 	atomic_set_release(&printk_cpulock_owner,
 			   -1); /* LMM(__printk_cpu_unlock:B) */
+
+	if (trigger_kgdb) {
+		pr_warn("re-triggering kgdb roundup for CPU#%d\n", cpu);
+		kgdb_roundup_cpu(cpu);
+	}
 }
 EXPORT_SYMBOL(__printk_cpu_unlock);
+
+bool kgdb_roundup_delay(unsigned int cpu)
+{
+	if (cpu != atomic_read(&printk_cpulock_owner))
+		return false;
+
+	kgdb_cpu = cpu;
+	return true;
+}
+EXPORT_SYMBOL(kgdb_roundup_delay);
 #endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PRINTK
+static void pr_msleep(bool may_sleep, int ms)
+{
+	if (may_sleep) {
+		msleep(ms);
+	} else {
+		while (ms--)
+			udelay(1000);
+	}
+}
+
+/**
+ * pr_flush() - Wait for printing threads to catch up.
+ *
+ * @timeout_ms:        The maximum time (in ms) to wait.
+ * @reset_on_progress: Reset the timeout if forward progress is seen.
+ *
+ * A value of 0 for @timeout_ms means no waiting will occur. A value of -1
+ * represents infinite waiting.
+ *
+ * If @reset_on_progress is true, the timeout will be reset whenever any
+ * printer has been seen to make some forward progress.
+ *
+ * Context: Any context.
+ * Return: true if all enabled printers are caught up.
+ */
+bool pr_flush(int timeout_ms, bool reset_on_progress)
+{
+	int remaining = timeout_ms;
+	struct console *con;
+	u64 last_diff = 0;
+	bool may_sleep;
+	u64 printk_seq;
+	u64 diff;
+	u64 seq;
+
+	may_sleep = (preemptible() &&
+		     !in_softirq() &&
+		     system_state >= SYSTEM_RUNNING);
+
+	seq = prb_next_seq(prb);
+
+	for (;;) {
+		diff = 0;
+
+		for_each_console(con) {
+			if (!(con->flags & CON_ENABLED))
+				continue;
+			if (!con->write && !con->write_atomic)
+				continue;
+			printk_seq = read_console_seq(con);
+			if (printk_seq < seq)
+				diff += seq - printk_seq;
+		}
+
+		if (diff != last_diff && reset_on_progress)
+			remaining = timeout_ms;
+
+		if (diff == 0 || remaining == 0)
+			break;
+
+		if (remaining < 0) {
+			pr_msleep(may_sleep, 100);
+		} else if (remaining < 100) {
+			pr_msleep(may_sleep, remaining);
+			remaining = 0;
+		} else {
+			pr_msleep(may_sleep, 100);
+			remaining -= 100;
+		}
+
+		last_diff = diff;
+	}
+
+	return (diff == 0);
+}
+EXPORT_SYMBOL(pr_flush);
+#endif /* CONFIG_PRINTK */
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 8e949e40bfe3a..ca2063b7691fb 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -197,7 +197,18 @@ static bool ptrace_freeze_traced(struct task_struct *task)
 	spin_lock_irq(&task->sighand->siglock);
 	if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
 	    !__fatal_signal_pending(task)) {
+#ifdef CONFIG_PREEMPT_RT
+		unsigned long flags;
+
+		raw_spin_lock_irqsave(&task->pi_lock, flags);
+		if (READ_ONCE(task->__state) & __TASK_TRACED)
+			WRITE_ONCE(task->__state, __TASK_TRACED);
+		else
+			task->saved_state = __TASK_TRACED;
+		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+#else
 		WRITE_ONCE(task->__state, __TASK_TRACED);
+#endif
 		ret = true;
 	}
 	spin_unlock_irq(&task->sighand->siglock);
@@ -207,7 +218,11 @@ static bool ptrace_freeze_traced(struct task_struct *task)
 
 static void ptrace_unfreeze_traced(struct task_struct *task)
 {
-	if (READ_ONCE(task->__state) != __TASK_TRACED)
+	unsigned long flags;
+	bool frozen = true;
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT) &&
+	    READ_ONCE(task->__state) != __TASK_TRACED)
 		return;
 
 	WARN_ON(!task->ptrace || task->parent != current);
@@ -217,12 +232,21 @@ static void ptrace_unfreeze_traced(struct task_struct *task)
 	 * Recheck state under the lock to close this race.
 	 */
 	spin_lock_irq(&task->sighand->siglock);
-	if (READ_ONCE(task->__state) == __TASK_TRACED) {
-		if (__fatal_signal_pending(task))
-			wake_up_state(task, __TASK_TRACED);
-		else
-			WRITE_ONCE(task->__state, TASK_TRACED);
-	}
+	raw_spin_lock_irqsave(&task->pi_lock, flags);
+	if (READ_ONCE(task->__state) == __TASK_TRACED)
+		WRITE_ONCE(task->__state, TASK_TRACED);
+
+#ifdef CONFIG_PREEMPT_RT
+	else if (task->saved_state == __TASK_TRACED)
+		task->saved_state = TASK_TRACED;
+#endif
+	else
+		frozen = false;
+	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+
+	if (frozen && __fatal_signal_pending(task))
+		wake_up_state(task, __TASK_TRACED);
+
 	spin_unlock_irq(&task->sighand->siglock);
 }
 
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 0a83d0ce46d78..bfb0851e7ec7d 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -1380,7 +1380,7 @@ static void test_rcu_tasks_callback(struct rcu_head *rhp)
 	rttd->notrun = true;
 }
 
-static void rcu_tasks_initiate_self_tests(void)
+void rcu_tasks_initiate_self_tests(void)
 {
 	pr_info("Running RCU-tasks wait API self tests\n");
 #ifdef CONFIG_TASKS_RCU
@@ -1417,9 +1417,7 @@ static int rcu_tasks_verify_self_tests(void)
 	return ret;
 }
 late_initcall(rcu_tasks_verify_self_tests);
-#else /* #ifdef CONFIG_PROVE_RCU */
-static void rcu_tasks_initiate_self_tests(void) { }
-#endif /* #else #ifdef CONFIG_PROVE_RCU */
+#endif /* #ifdef CONFIG_PROVE_RCU */
 
 void __init rcu_init_tasks_generic(void)
 {
@@ -1434,9 +1432,6 @@ void __init rcu_init_tasks_generic(void)
 #ifdef CONFIG_TASKS_TRACE_RCU
 	rcu_spawn_tasks_trace_kthread();
 #endif
-
-	// Run the self-tests.
-	rcu_tasks_initiate_self_tests();
 }
 
 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 185d37b02dc9c..65dbe718b799d 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2293,13 +2293,13 @@ rcu_report_qs_rdp(struct rcu_data *rdp)
 {
 	unsigned long flags;
 	unsigned long mask;
-	bool needwake = false;
-	const bool offloaded = rcu_rdp_is_offloaded(rdp);
+	bool offloaded, needwake = false;
 	struct rcu_node *rnp;
 
 	WARN_ON_ONCE(rdp->cpu != smp_processor_id());
 	rnp = rdp->mynode;
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
+	offloaded = rcu_rdp_is_offloaded(rdp);
 	if (rdp->cpu_no_qs.b.norm || rdp->gp_seq != rnp->gp_seq ||
 	    rdp->gpwrap) {
 
@@ -2461,7 +2461,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
 	int div;
 	bool __maybe_unused empty;
 	unsigned long flags;
-	const bool offloaded = rcu_rdp_is_offloaded(rdp);
+	bool offloaded;
 	struct rcu_head *rhp;
 	struct rcu_cblist rcl = RCU_CBLIST_INITIALIZER(rcl);
 	long bl, count = 0;
@@ -2487,6 +2487,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
 	rcu_nocb_lock(rdp);
 	WARN_ON_ONCE(cpu_is_offline(smp_processor_id()));
 	pending = rcu_segcblist_n_cbs(&rdp->cblist);
+	offloaded = rcu_rdp_is_offloaded(rdp);
 	div = READ_ONCE(rcu_divisor);
 	div = div < 0 ? 7 : div > sizeof(long) * 8 - 2 ? sizeof(long) * 8 - 2 : div;
 	bl = max(rdp->blimit, pending >> div);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c4e9fac7507a9..276499caf4717 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -75,7 +75,11 @@ __read_mostly int sysctl_resched_latency_warn_once = 1;
  * Number of tasks to iterate in a single balance run.
  * Limited because this is done with IRQs disabled.
  */
+#ifdef CONFIG_PREEMPT_RT
+const_debug unsigned int sysctl_sched_nr_migrate = 8;
+#else
 const_debug unsigned int sysctl_sched_nr_migrate = 32;
+#endif
 
 /*
  * period over which we measure -rt task CPU usage in us.
@@ -986,6 +990,46 @@ void resched_curr(struct rq *rq)
 		trace_sched_wake_idle_without_ipi(cpu);
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+
+static int tsk_is_polling(struct task_struct *p)
+{
+#ifdef TIF_POLLING_NRFLAG
+	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
+#else
+	return 0;
+#endif
+}
+
+void resched_curr_lazy(struct rq *rq)
+{
+	struct task_struct *curr = rq->curr;
+	int cpu;
+
+	if (!sched_feat(PREEMPT_LAZY)) {
+		resched_curr(rq);
+		return;
+	}
+
+	if (test_tsk_need_resched(curr))
+		return;
+
+	if (test_tsk_need_resched_lazy(curr))
+		return;
+
+	set_tsk_need_resched_lazy(curr);
+
+	cpu = cpu_of(rq);
+	if (cpu == smp_processor_id())
+		return;
+
+	/* NEED_RESCHED_LAZY must be visible before we test polling */
+	smp_mb();
+	if (!tsk_is_polling(curr))
+		smp_send_reschedule(cpu);
+}
+#endif
+
 void resched_cpu(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
@@ -2160,6 +2204,7 @@ void migrate_disable(void)
 	preempt_disable();
 	this_rq()->nr_pinned++;
 	p->migration_disabled = 1;
+	preempt_lazy_disable();
 	preempt_enable();
 }
 EXPORT_SYMBOL_GPL(migrate_disable);
@@ -2171,6 +2216,8 @@ void migrate_enable(void)
 	if (p->migration_disabled > 1) {
 		p->migration_disabled--;
 		return;
+	} else if (WARN_ON_ONCE(p->migration_disabled == 0)) {
+		return;
 	}
 
 	/*
@@ -2188,6 +2235,7 @@ void migrate_enable(void)
 	barrier();
 	p->migration_disabled = 0;
 	this_rq()->nr_pinned--;
+	preempt_lazy_enable();
 	preempt_enable();
 }
 EXPORT_SYMBOL_GPL(migrate_enable);
@@ -3258,7 +3306,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state
 		 * is actually now running somewhere else!
 		 */
 		while (task_running(rq, p)) {
-			if (match_state && unlikely(READ_ONCE(p->__state) != match_state))
+			if (match_state && !task_match_state_lock(p, match_state))
 				return 0;
 			cpu_relax();
 		}
@@ -3273,7 +3321,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state
 		running = task_running(rq, p);
 		queued = task_on_rq_queued(p);
 		ncsw = 0;
-		if (!match_state || READ_ONCE(p->__state) == match_state)
+		if (!match_state || task_match_state_or_saved(p, match_state))
 			ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
 		task_rq_unlock(rq, p, &rf);
 
@@ -3307,7 +3355,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state
 			ktime_t to = NSEC_PER_SEC / HZ;
 
 			set_current_state(TASK_UNINTERRUPTIBLE);
-			schedule_hrtimeout(&to, HRTIMER_MODE_REL);
+			schedule_hrtimeout(&to, HRTIMER_MODE_REL_HARD);
 			continue;
 		}
 
@@ -4450,6 +4498,9 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
 	p->on_cpu = 0;
 #endif
 	init_task_preempt_count(p);
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+	task_thread_info(p)->preempt_lazy_count = 0;
+#endif
 #ifdef CONFIG_SMP
 	plist_node_init(&p->pushable_tasks, MAX_PRIO);
 	RB_CLEAR_NODE(&p->pushable_dl_tasks);
@@ -4945,20 +4996,18 @@ static struct rq *finish_task_switch(struct task_struct *prev)
 	 */
 	if (mm) {
 		membarrier_mm_sync_core_before_usermode(mm);
-		mmdrop(mm);
+		mmdrop_sched(mm);
 	}
 	if (unlikely(prev_state == TASK_DEAD)) {
 		if (prev->sched_class->task_dead)
 			prev->sched_class->task_dead(prev);
 
 		/*
-		 * Remove function-return probe instances associated with this
-		 * task and put them back on the free list.
+		 * Release VMAP'ed task stack immediate for reuse. On RT
+		 * enabled kernels this is delayed for latency reasons.
 		 */
-		kprobe_flush_task(prev);
-
-		/* Task is done with its stack. */
-		put_task_stack(prev);
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+			put_task_stack(prev);
 
 		put_task_struct_rcu_user(prev);
 	}
@@ -6358,6 +6407,7 @@ static void __sched notrace __schedule(unsigned int sched_mode)
 
 	next = pick_next_task(rq, prev, &rf);
 	clear_tsk_need_resched(prev);
+	clear_tsk_need_resched_lazy(prev);
 	clear_preempt_need_resched();
 #ifdef CONFIG_SCHED_DEBUG
 	rq->last_seen_need_resched_ns = 0;
@@ -6579,6 +6629,30 @@ static void __sched notrace preempt_schedule_common(void)
 	} while (need_resched());
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+/*
+ * If TIF_NEED_RESCHED is then we allow to be scheduled away since this is
+ * set by a RT task. Oterwise we try to avoid beeing scheduled out as long as
+ * preempt_lazy_count counter >0.
+ */
+static __always_inline int preemptible_lazy(void)
+{
+	if (test_thread_flag(TIF_NEED_RESCHED))
+		return 1;
+	if (current_thread_info()->preempt_lazy_count)
+		return 0;
+	return 1;
+}
+
+#else
+
+static inline int preemptible_lazy(void)
+{
+	return 1;
+}
+
+#endif
+
 #ifdef CONFIG_PREEMPTION
 /*
  * This is the entry point to schedule() from in-kernel preemption
@@ -6592,7 +6666,8 @@ asmlinkage __visible void __sched notrace preempt_schedule(void)
 	 */
 	if (likely(!preemptible()))
 		return;
-
+	if (!preemptible_lazy())
+		return;
 	preempt_schedule_common();
 }
 NOKPROBE_SYMBOL(preempt_schedule);
@@ -6625,6 +6700,9 @@ asmlinkage __visible void __sched notrace preempt_schedule_notrace(void)
 	if (likely(!preemptible()))
 		return;
 
+	if (!preemptible_lazy())
+		return;
+
 	do {
 		/*
 		 * Because the function tracer can trace preempt_count_sub()
@@ -8785,7 +8863,9 @@ void __init init_idle(struct task_struct *idle, int cpu)
 
 	/* Set the preempt count _outside_ the spinlocks! */
 	init_idle_preempt_count(idle, cpu);
-
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+	task_thread_info(idle)->preempt_lazy_count = 0;
+#endif
 	/*
 	 * The idle tasks have their own, simple scheduling class:
 	 */
@@ -9588,14 +9668,8 @@ void __init sched_init(void)
 }
 
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
-static inline int preempt_count_equals(int preempt_offset)
-{
-	int nested = preempt_count() + rcu_preempt_depth();
-
-	return (nested == preempt_offset);
-}
 
-void __might_sleep(const char *file, int line, int preempt_offset)
+void __might_sleep(const char *file, int line)
 {
 	unsigned int state = get_current_state();
 	/*
@@ -9609,11 +9683,32 @@ void __might_sleep(const char *file, int line, int preempt_offset)
 			(void *)current->task_state_change,
 			(void *)current->task_state_change);
 
-	___might_sleep(file, line, preempt_offset);
+	__might_resched(file, line, 0);
 }
 EXPORT_SYMBOL(__might_sleep);
 
-void ___might_sleep(const char *file, int line, int preempt_offset)
+static void print_preempt_disable_ip(int preempt_offset, unsigned long ip)
+{
+	if (!IS_ENABLED(CONFIG_DEBUG_PREEMPT))
+		return;
+
+	if (preempt_count() == preempt_offset)
+		return;
+
+	pr_err("Preemption disabled at:");
+	print_ip_sym(KERN_ERR, ip);
+}
+
+static inline bool resched_offsets_ok(unsigned int offsets)
+{
+	unsigned int nested = preempt_count();
+
+	nested += rcu_preempt_depth() << MIGHT_RESCHED_RCU_SHIFT;
+
+	return nested == offsets;
+}
+
+void __might_resched(const char *file, int line, unsigned int offsets)
 {
 	/* Ratelimiting timestamp: */
 	static unsigned long prev_jiffy;
@@ -9623,7 +9718,7 @@ void ___might_sleep(const char *file, int line, int preempt_offset)
 	/* WARN_ON_ONCE() by default, no rate limit required: */
 	rcu_sleep_check();
 
-	if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
+	if ((resched_offsets_ok(offsets) && !irqs_disabled() &&
 	     !is_idle_task(current) && !current->non_block_count) ||
 	    system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
 	    oops_in_progress)
@@ -9636,29 +9731,33 @@ void ___might_sleep(const char *file, int line, int preempt_offset)
 	/* Save this before calling printk(), since that will clobber it: */
 	preempt_disable_ip = get_preempt_disable_ip(current);
 
-	printk(KERN_ERR
-		"BUG: sleeping function called from invalid context at %s:%d\n",
-			file, line);
-	printk(KERN_ERR
-		"in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n",
-			in_atomic(), irqs_disabled(), current->non_block_count,
-			current->pid, current->comm);
+	pr_err("BUG: sleeping function called from invalid context at %s:%d\n",
+	       file, line);
+	pr_err("in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n",
+	       in_atomic(), irqs_disabled(), current->non_block_count,
+	       current->pid, current->comm);
+	pr_err("preempt_count: %x, expected: %x\n", preempt_count(),
+	       offsets & MIGHT_RESCHED_PREEMPT_MASK);
+
+	if (IS_ENABLED(CONFIG_PREEMPT_RCU)) {
+		pr_err("RCU nest depth: %d, expected: %u\n",
+		       rcu_preempt_depth(), offsets >> MIGHT_RESCHED_RCU_SHIFT);
+	}
 
 	if (task_stack_end_corrupted(current))
-		printk(KERN_EMERG "Thread overran stack, or stack corrupted\n");
+		pr_emerg("Thread overran stack, or stack corrupted\n");
 
 	debug_show_held_locks(current);
 	if (irqs_disabled())
 		print_irqtrace_events(current);
-	if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)
-	    && !preempt_count_equals(preempt_offset)) {
-		pr_err("Preemption disabled at:");
-		print_ip_sym(KERN_ERR, preempt_disable_ip);
-	}
+
+	print_preempt_disable_ip(offsets & MIGHT_RESCHED_PREEMPT_MASK,
+				 preempt_disable_ip);
+
 	dump_stack();
 	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
 }
-EXPORT_SYMBOL(___might_sleep);
+EXPORT_SYMBOL(__might_resched);
 
 void __cant_sleep(const char *file, int line, int preempt_offset)
 {
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f2a58e54268ea..f20755f9fc1ae 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4626,7 +4626,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 	ideal_runtime = sched_slice(cfs_rq, curr);
 	delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
 	if (delta_exec > ideal_runtime) {
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 		/*
 		 * The current task ran long enough, ensure it doesn't get
 		 * re-elected due to buddy favours.
@@ -4650,7 +4650,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 		return;
 
 	if (delta > ideal_runtime)
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 }
 
 static void
@@ -4796,7 +4796,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
 	 * validating it and just reschedule.
 	 */
 	if (queued) {
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 		return;
 	}
 	/*
@@ -4936,7 +4936,7 @@ static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec)
 	 * hierarchy can be throttled
 	 */
 	if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 }
 
 static __always_inline
@@ -5699,7 +5699,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
 
 		if (delta < 0) {
 			if (task_current(rq, p))
-				resched_curr(rq);
+				resched_curr_lazy(rq);
 			return;
 		}
 		hrtick_start(rq, delta);
@@ -7444,7 +7444,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 	return;
 
 preempt:
-	resched_curr(rq);
+	resched_curr_lazy(rq);
 	/*
 	 * Only set the backward buddy when the current task is still
 	 * on the rq. This can happen when a wakeup gets interleaved
@@ -11513,7 +11513,7 @@ static void task_fork_fair(struct task_struct *p)
 		 * 'current' within the tree based on its new key value.
 		 */
 		swap(curr->vruntime, se->vruntime);
-		resched_curr(rq);
+		resched_curr_lazy(rq);
 	}
 
 	se->vruntime -= cfs_rq->min_vruntime;
@@ -11540,7 +11540,7 @@ prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)
 	 */
 	if (task_current(rq, p)) {
 		if (p->prio > oldprio)
-			resched_curr(rq);
+			resched_curr_lazy(rq);
 	} else
 		check_preempt_curr(rq, p, 0);
 }
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 1a8fb0d1709a5..c516fa97729f8 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -46,11 +46,19 @@ SCHED_FEAT(DOUBLE_TICK, false)
  */
 SCHED_FEAT(NONTASK_CAPACITY, true)
 
+#ifdef CONFIG_PREEMPT_RT
+SCHED_FEAT(TTWU_QUEUE, false)
+# ifdef CONFIG_PREEMPT_LAZY
+SCHED_FEAT(PREEMPT_LAZY, true)
+# endif
+#else
+
 /*
  * Queue remote wakeups on the target CPU and process them
  * using the scheduler IPI. Reduces rq->lock contention/bounces.
  */
 SCHED_FEAT(TTWU_QUEUE, true)
+#endif
 
 /*
  * When doing wakeups, attempt to limit superfluous scans of the LLC domain.
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index f58040a51e334..1f6a1cedf7040 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2327,6 +2327,15 @@ extern void reweight_task(struct task_struct *p, const struct load_weight *lw);
 extern void resched_curr(struct rq *rq);
 extern void resched_cpu(int cpu);
 
+#ifdef CONFIG_PREEMPT_LAZY
+extern void resched_curr_lazy(struct rq *rq);
+#else
+static inline void resched_curr_lazy(struct rq *rq)
+{
+	resched_curr(rq);
+}
+#endif
+
 extern struct rt_bandwidth def_rt_bandwidth;
 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
 
diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c
index e1c655f928c74..f230b1ac7f910 100644
--- a/kernel/sched/swait.c
+++ b/kernel/sched/swait.c
@@ -64,6 +64,7 @@ void swake_up_all(struct swait_queue_head *q)
 	struct swait_queue *curr;
 	LIST_HEAD(tmp);
 
+	WARN_ON(irqs_disabled());
 	raw_spin_lock_irq(&q->lock);
 	list_splice_init(&q->task_list, &tmp);
 	while (!list_empty(&tmp)) {
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 8c82ca3aa652f..89bd202757f59 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -526,7 +526,7 @@ static int init_rootdomain(struct root_domain *rd)
 #ifdef HAVE_RT_PUSH_IPI
 	rd->rto_cpu = -1;
 	raw_spin_lock_init(&rd->rto_lock);
-	init_irq_work(&rd->rto_push_work, rto_push_irq_work_func);
+	rd->rto_push_work = IRQ_WORK_INIT_HARD(rto_push_irq_work_func);
 #endif
 
 	rd->visit_gen = 0;
diff --git a/kernel/signal.c b/kernel/signal.c
index 662377d23c95d..3bca0ba68d9a2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1324,6 +1324,34 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t,
 	struct k_sigaction *action;
 	int sig = info->si_signo;
 
+	/*
+	 * On some archs, PREEMPT_RT has to delay sending a signal from a trap
+	 * since it can not enable preemption, and the signal code's spin_locks
+	 * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will
+	 * send the signal on exit of the trap.
+	 */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+	if (in_atomic()) {
+		struct task_struct *t = current;
+
+		if (WARN_ON_ONCE(t->forced_info.si_signo))
+			return 0;
+
+		if (is_si_special(info)) {
+			WARN_ON_ONCE(info != SEND_SIG_PRIV);
+			t->forced_info.si_signo = info->si_signo;
+			t->forced_info.si_errno = 0;
+			t->forced_info.si_code = SI_KERNEL;
+			t->forced_info.si_pid = 0;
+			t->forced_info.si_uid = 0;
+		} else {
+			t->forced_info = *info;
+		}
+
+		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+		return 0;
+	}
+#endif
 	spin_lock_irqsave(&t->sighand->siglock, flags);
 	action = &t->sighand->action[sig-1];
 	ignored = action->sa.sa_handler == SIG_IGN;
@@ -2320,16 +2348,8 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t
 		if (gstop_done && ptrace_reparented(current))
 			do_notify_parent_cldstop(current, false, why);
 
-		/*
-		 * Don't want to allow preemption here, because
-		 * sys_ptrace() needs this task to be inactive.
-		 *
-		 * XXX: implement read_unlock_no_resched().
-		 */
-		preempt_disable();
 		read_unlock(&tasklist_lock);
 		cgroup_enter_frozen();
-		preempt_enable_no_resched();
 		freezable_schedule();
 		cgroup_leave_frozen(true);
 	} else {
diff --git a/kernel/smp.c b/kernel/smp.c
index 387df30ca5609..2e08f377fe514 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -690,10 +690,20 @@ void flush_smp_call_function_from_idle(void)
 
 	cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->idle, CFD_SEQ_NOCPU,
 		      smp_processor_id(), CFD_SEQ_IDLE);
+
 	local_irq_save(flags);
 	flush_smp_call_function_queue(true);
-	if (local_softirq_pending())
-		do_softirq();
+
+	if (local_softirq_pending()) {
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			do_softirq();
+		} else {
+			struct task_struct *ksoftirqd = this_cpu_ksoftirqd();
+
+			if (ksoftirqd && !task_is_running(ksoftirqd))
+				wake_up_process(ksoftirqd);
+		}
+	}
 
 	local_irq_restore(flags);
 }
diff --git a/kernel/softirq.c b/kernel/softirq.c
index d63d827da2d6a..557a4160c6479 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -80,21 +80,6 @@ static void wakeup_softirqd(void)
 		wake_up_process(tsk);
 }
 
-/*
- * If ksoftirqd is scheduled, we do not want to process pending softirqs
- * right now. Let ksoftirqd handle this at its own rate, to get fairness,
- * unless we're doing some of the synchronous softirqs.
- */
-#define SOFTIRQ_NOW_MASK ((1 << HI_SOFTIRQ) | (1 << TASKLET_SOFTIRQ))
-static bool ksoftirqd_running(unsigned long pending)
-{
-	struct task_struct *tsk = __this_cpu_read(ksoftirqd);
-
-	if (pending & SOFTIRQ_NOW_MASK)
-		return false;
-	return tsk && task_is_running(tsk) && !__kthread_should_park(tsk);
-}
-
 #ifdef CONFIG_TRACE_IRQFLAGS
 DEFINE_PER_CPU(int, hardirqs_enabled);
 DEFINE_PER_CPU(int, hardirq_context);
@@ -252,7 +237,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
 		goto out;
 
 	pending = local_softirq_pending();
-	if (!pending || ksoftirqd_running(pending))
+	if (!pending)
 		goto out;
 
 	/*
@@ -437,9 +422,6 @@ static inline bool should_wake_ksoftirqd(void)
 
 static inline void invoke_softirq(void)
 {
-	if (ksoftirqd_running(local_softirq_pending()))
-		return;
-
 	if (!force_irqthreads() || !__this_cpu_read(ksoftirqd)) {
 #ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
 		/*
@@ -473,7 +455,7 @@ asmlinkage __visible void do_softirq(void)
 
 	pending = local_softirq_pending();
 
-	if (pending && !ksoftirqd_running(pending))
+	if (pending)
 		do_softirq_own_stack();
 
 	local_irq_restore(flags);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1a29a9d9e8685..d6d2fa350356d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2630,7 +2630,13 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status)
 		trace_flags |= TRACE_FLAG_NEED_RESCHED;
 	if (test_preempt_need_resched())
 		trace_flags |= TRACE_FLAG_PREEMPT_RESCHED;
-	return (trace_flags << 16) | (min_t(unsigned int, pc & 0xff, 0xf)) |
+#ifdef CONFIG_PREEMPT_LAZY
+	if (need_resched_lazy())
+		trace_flags |= TRACE_FLAG_NEED_RESCHED_LAZY;
+#endif
+
+	return (trace_flags << 24) | (min_t(unsigned int, pc & 0xff, 0xf)) |
+		(preempt_lazy_count() & 0xff) << 16 |
 		(min_t(unsigned int, migration_disable_value(), 0xf)) << 4;
 }
 
@@ -4214,15 +4220,17 @@ unsigned long trace_total_entries(struct trace_array *tr)
 
 static void print_lat_help_header(struct seq_file *m)
 {
-	seq_puts(m, "#                    _------=> CPU#            \n"
-		    "#                   / _-----=> irqs-off        \n"
-		    "#                  | / _----=> need-resched    \n"
-		    "#                  || / _---=> hardirq/softirq \n"
-		    "#                  ||| / _--=> preempt-depth   \n"
-		    "#                  |||| / _-=> migrate-disable \n"
-		    "#                  ||||| /     delay           \n"
-		    "#  cmd     pid     |||||| time  |   caller     \n"
-		    "#     \\   /        ||||||  \\    |    /       \n");
+	seq_puts(m, "#                    _--------=> CPU#            \n"
+		    "#                   / _-------=> irqs-off        \n"
+		    "#                  | / _------=> need-resched    \n"
+		    "#                  || / _-----=> need-resched-lazy\n"
+		    "#                  ||| / _----=> hardirq/softirq \n"
+		    "#                  |||| / _---=> preempt-depth   \n"
+		    "#                  ||||| / _--=> preempt-lazy-depth\n"
+		    "#                  |||||| / _-=> migrate-disable \n"
+		    "#                  ||||||| /     delay           \n"
+		    "#  cmd     pid     |||||||| time  |   caller     \n"
+		    "#     \\   /        ||||||||  \\    |    /       \n");
 }
 
 static void print_event_info(struct array_buffer *buf, struct seq_file *m)
@@ -4256,14 +4264,16 @@ static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file
 
 	print_event_info(buf, m);
 
-	seq_printf(m, "#                            %.*s  _-----=> irqs-off\n", prec, space);
-	seq_printf(m, "#                            %.*s / _----=> need-resched\n", prec, space);
-	seq_printf(m, "#                            %.*s| / _---=> hardirq/softirq\n", prec, space);
-	seq_printf(m, "#                            %.*s|| / _--=> preempt-depth\n", prec, space);
-	seq_printf(m, "#                            %.*s||| / _-=> migrate-disable\n", prec, space);
-	seq_printf(m, "#                            %.*s|||| /     delay\n", prec, space);
-	seq_printf(m, "#           TASK-PID  %.*s CPU#  |||||  TIMESTAMP  FUNCTION\n", prec, "     TGID   ");
-	seq_printf(m, "#              | |    %.*s   |   |||||     |         |\n", prec, "       |    ");
+	seq_printf(m, "#                            %.*s  _-------=> irqs-off\n", prec, space);
+	seq_printf(m, "#                            %.*s / _------=> need-resched\n", prec, space);
+	seq_printf(m, "#                            %.*s| / _-----=> need-resched-lazy\n", prec, space);
+	seq_printf(m, "#                            %.*s|| / _----=> hardirq/softirq\n", prec, space);
+	seq_printf(m, "#                            %.*s||| / _---=> preempt-depth\n", prec, space);
+	seq_printf(m, "#                            %.*s|||| / _--=> preempt-lazy-depth\n", prec, space);
+	seq_printf(m, "#                            %.*s||||| / _-=> migrate-disable\n", prec, space);
+	seq_printf(m, "#                            %.*s|||||| /     delay\n", prec, space);
+	seq_printf(m, "#           TASK-PID  %.*s CPU#  |||||||  TIMESTAMP  FUNCTION\n", prec, "     TGID   ");
+	seq_printf(m, "#              | |    %.*s   |   |||||||      |         |\n", prec, "       |    ");
 }
 
 void
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index b7c643d5f63ae..23d859f4c809b 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -193,6 +193,7 @@ static int trace_define_common_fields(void)
 	/* Holds both preempt_count and migrate_disable */
 	__common_field(unsigned char, preempt_count);
 	__common_field(int, pid);
+	__common_field(unsigned char, preempt_lazy_count);
 
 	return ret;
 }
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 6b4d3f3abdae2..460bc8245e4ae 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -451,6 +451,7 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 {
 	char hardsoft_irq;
 	char need_resched;
+	char need_resched_lazy;
 	char irqs_off;
 	int hardirq;
 	int softirq;
@@ -481,6 +482,9 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 		break;
 	}
 
+	need_resched_lazy =
+		(entry->flags & TRACE_FLAG_NEED_RESCHED_LAZY) ? 'L' : '.';
+
 	hardsoft_irq =
 		(nmi && hardirq)     ? 'Z' :
 		nmi                  ? 'z' :
@@ -489,14 +493,20 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 		softirq              ? 's' :
 		                       '.' ;
 
-	trace_seq_printf(s, "%c%c%c",
-			 irqs_off, need_resched, hardsoft_irq);
+	trace_seq_printf(s, "%c%c%c%c",
+			 irqs_off, need_resched, need_resched_lazy,
+			 hardsoft_irq);
 
 	if (entry->preempt_count & 0xf)
 		trace_seq_printf(s, "%x", entry->preempt_count & 0xf);
 	else
 		trace_seq_putc(s, '.');
 
+	if (entry->preempt_lazy_count)
+		trace_seq_printf(s, "%x", entry->preempt_lazy_count);
+	else
+		trace_seq_putc(s, '.');
+
 	if (entry->preempt_count & 0xf0)
 		trace_seq_printf(s, "%x", entry->preempt_count >> 4);
 	else
diff --git a/lib/bug.c b/lib/bug.c
index 45a0584f65417..03a87df69ed23 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -206,6 +206,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
 	else
 		pr_crit("Kernel BUG at %pB [verbose debug info unavailable]\n",
 			(void *)bugaddr);
+	pr_flush(1000, true);
 
 	return BUG_TRAP_TYPE_BUG;
 }
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 81b319d574176..07f48e0195cec 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -600,6 +600,27 @@ static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket
 	return NULL;
 }
 
+static void debug_objects_fill_pool(void)
+{
+	/*
+	 * On RT enabled kernels the pool refill must happen in preemptible
+	 * context -- for !RT kernels we rely on the fact that spinlock_t and
+	 * raw_spinlock_t are basically the same type and this lock-type
+	 * inversion works just fine.
+	 */
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) {
+		/*
+		 * Annotate away the spinlock_t inside raw_spinlock_t warning
+		 * by temporarily raising the wait-type to WAIT_SLEEP, matching
+		 * the preemptible() condition above.
+		 */
+		static DEFINE_WAIT_OVERRIDE_MAP(fill_pool_map, LD_WAIT_SLEEP);
+		lock_map_acquire_try(&fill_pool_map);
+		fill_pool();
+		lock_map_release(&fill_pool_map);
+	}
+}
+
 static void
 __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack)
 {
@@ -607,12 +628,7 @@ __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack
 	struct debug_bucket *db;
 	unsigned long flags;
 
-	/*
-	 * On RT enabled kernels the pool refill must happen in preemptible
-	 * context:
-	 */
-	if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible())
-		fill_pool();
+	debug_objects_fill_pool();
 
 	db = get_bucket((unsigned long) addr);
 
@@ -689,6 +705,8 @@ int debug_object_activate(void *addr, const struct debug_obj_descr *descr)
 	if (!debug_objects_enabled)
 		return 0;
 
+	debug_objects_fill_pool();
+
 	db = get_bucket((unsigned long) addr);
 
 	raw_spin_lock_irqsave(&db->lock, flags);
@@ -884,6 +902,8 @@ void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr)
 	if (!debug_objects_enabled)
 		return;
 
+	debug_objects_fill_pool();
+
 	db = get_bucket((unsigned long) addr);
 
 	raw_spin_lock_irqsave(&db->lock, flags);
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 6b7f1bf6715d8..6e8ae42c7e273 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -102,9 +102,9 @@ asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
 	 * Permit this cpu to perform nested stack dumps while serialising
 	 * against other CPUs
 	 */
-	printk_cpu_lock_irqsave(flags);
+	raw_printk_cpu_lock_irqsave(flags);
 	__dump_stack(log_lvl);
-	printk_cpu_unlock_irqrestore(flags);
+	raw_printk_cpu_unlock_irqrestore(flags);
 }
 EXPORT_SYMBOL(dump_stack_lvl);
 
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
index 2f17b488d58e1..2b9f797642f60 100644
--- a/lib/irq_poll.c
+++ b/lib/irq_poll.c
@@ -191,11 +191,13 @@ static int irq_poll_cpu_dead(unsigned int cpu)
 	 * If a CPU goes away, splice its entries to the current CPU
 	 * and trigger a run of the softirq
 	 */
+	local_bh_disable();
 	local_irq_disable();
 	list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
 			 this_cpu_ptr(&blk_cpu_iopoll));
 	__raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
 	local_irq_enable();
+	local_bh_enable();
 
 	return 0;
 }
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 161108e5d2fe0..1266ea3726d73 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -26,6 +26,12 @@
 #include <linux/rtmutex.h>
 #include <linux/local_lock.h>
 
+#ifdef CONFIG_PREEMPT_RT
+# define NON_RT(...)
+#else
+# define NON_RT(...)	__VA_ARGS__
+#endif
+
 /*
  * Change this to 1 if you want to see the failure printouts:
  */
@@ -139,7 +145,7 @@ static DEFINE_RT_MUTEX(rtmutex_Z2);
 
 #endif
 
-static local_lock_t local_A = INIT_LOCAL_LOCK(local_A);
+static DEFINE_PER_CPU(local_lock_t, local_A);
 
 /*
  * non-inlined runtime initializers, to let separate locks share
@@ -712,12 +718,18 @@ GENERATE_TESTCASE(ABCDBCDA_rtmutex);
 
 #undef E
 
+#ifdef CONFIG_PREEMPT_RT
+# define RT_PREPARE_DBL_UNLOCK()	{ migrate_disable(); rcu_read_lock(); }
+#else
+# define RT_PREPARE_DBL_UNLOCK()
+#endif
 /*
  * Double unlock:
  */
 #define E()					\
 						\
 	LOCK(A);				\
+	RT_PREPARE_DBL_UNLOCK();		\
 	UNLOCK(A);				\
 	UNLOCK(A); /* fail */
 
@@ -802,6 +814,7 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_spin)
 
@@ -810,10 +823,12 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
 
+#ifndef CONFIG_PREEMPT_RT
 /*
  * Enabling hardirqs with a softirq-safe lock held:
  */
@@ -846,6 +861,8 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_rlock)
 #undef E1
 #undef E2
 
+#endif
+
 /*
  * Enabling irqs with an irq-safe lock held:
  */
@@ -875,6 +892,7 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_spin)
 
@@ -883,6 +901,7 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -921,6 +940,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_spin)
 
@@ -929,6 +949,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -969,6 +990,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_spin)
 
@@ -977,6 +999,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1031,6 +1054,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_spin)
 
@@ -1039,6 +1063,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1206,12 +1231,14 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_hard_rlock)
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-softirq.h"
 #include "locking-selftest-rlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft_rlock)
 
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1252,12 +1279,14 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_hard_rlock)
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-softirq.h"
 #include "locking-selftest-rlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft_rlock)
 
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1306,12 +1335,14 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_hard_rlock)
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-softirq.h"
 #include "locking-selftest-rlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_rlock)
 
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock)
+#endif
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 # define I_SPINLOCK(x)	lockdep_reset_lock(&lock_##x.dep_map)
@@ -1320,7 +1351,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock)
 # define I_MUTEX(x)	lockdep_reset_lock(&mutex_##x.dep_map)
 # define I_RWSEM(x)	lockdep_reset_lock(&rwsem_##x.dep_map)
 # define I_WW(x)	lockdep_reset_lock(&x.dep_map)
-# define I_LOCAL_LOCK(x) lockdep_reset_lock(&local_##x.dep_map)
+# define I_LOCAL_LOCK(x) lockdep_reset_lock(this_cpu_ptr(&local_##x.dep_map))
 #ifdef CONFIG_RT_MUTEXES
 # define I_RTMUTEX(x)	lockdep_reset_lock(&rtmutex_##x.dep_map)
 #endif
@@ -1380,7 +1411,7 @@ static void reset_locks(void)
 	init_shared_classes();
 	raw_spin_lock_init(&raw_lock_A);
 	raw_spin_lock_init(&raw_lock_B);
-	local_lock_init(&local_A);
+	local_lock_init(this_cpu_ptr(&local_A));
 
 	ww_mutex_init(&o, &ww_lockdep); ww_mutex_init(&o2, &ww_lockdep); ww_mutex_init(&o3, &ww_lockdep);
 	memset(&t, 0, sizeof(t)); memset(&t2, 0, sizeof(t2));
@@ -1398,7 +1429,13 @@ static int unexpected_testcase_failures;
 
 static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask)
 {
-	unsigned long saved_preempt_count = preempt_count();
+	int saved_preempt_count = preempt_count();
+#ifdef CONFIG_PREEMPT_RT
+#ifdef CONFIG_SMP
+	int saved_mgd_count = current->migration_disabled;
+#endif
+	int saved_rcu_count = current->rcu_read_lock_nesting;
+#endif
 
 	WARN_ON(irqs_disabled());
 
@@ -1432,6 +1469,18 @@ static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask)
 	 * count, so restore it:
 	 */
 	preempt_count_set(saved_preempt_count);
+
+#ifdef CONFIG_PREEMPT_RT
+#ifdef CONFIG_SMP
+	while (current->migration_disabled > saved_mgd_count)
+		migrate_enable();
+#endif
+
+	while (current->rcu_read_lock_nesting > saved_rcu_count)
+		rcu_read_unlock();
+	WARN_ON_ONCE(current->rcu_read_lock_nesting < saved_rcu_count);
+#endif
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 	if (softirq_count())
 		current->softirqs_enabled = 0;
@@ -1499,7 +1548,7 @@ static inline void print_testname(const char *testname)
 
 #define DO_TESTCASE_2x2RW(desc, name, nr)			\
 	DO_TESTCASE_2RW("hard-"desc, name##_hard, nr)		\
-	DO_TESTCASE_2RW("soft-"desc, name##_soft, nr)		\
+	NON_RT(DO_TESTCASE_2RW("soft-"desc, name##_soft, nr))	\
 
 #define DO_TESTCASE_6x2x2RW(desc, name)				\
 	DO_TESTCASE_2x2RW(desc, name, 123);			\
@@ -1547,19 +1596,19 @@ static inline void print_testname(const char *testname)
 
 #define DO_TESTCASE_2I(desc, name, nr)				\
 	DO_TESTCASE_1("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_1("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_1("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_2IB(desc, name, nr)				\
 	DO_TESTCASE_1B("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_1B("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_1B("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_6I(desc, name, nr)				\
 	DO_TESTCASE_3("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_3("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_3("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_6IRW(desc, name, nr)			\
 	DO_TESTCASE_3RW("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_3RW("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_3RW("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_2x3(desc, name)				\
 	DO_TESTCASE_3(desc, name, 12);				\
@@ -1651,6 +1700,20 @@ static void ww_test_fail_acquire(void)
 #endif
 }
 
+#ifdef CONFIG_PREEMPT_RT
+#define ww_mutex_base_lock(b)			rt_mutex_lock(b)
+#define ww_mutex_base_lock_nest_lock(b, b2)	rt_mutex_lock_nest_lock(b, b2)
+#define ww_mutex_base_lock_interruptible(b)	rt_mutex_lock_interruptible(b)
+#define ww_mutex_base_lock_killable(b)		rt_mutex_lock_killable(b)
+#define ww_mutex_base_unlock(b)			rt_mutex_unlock(b)
+#else
+#define ww_mutex_base_lock(b)			mutex_lock(b)
+#define ww_mutex_base_lock_nest_lock(b, b2)	mutex_lock_nest_lock(b, b2)
+#define ww_mutex_base_lock_interruptible(b)	mutex_lock_interruptible(b)
+#define ww_mutex_base_lock_killable(b)		mutex_lock_killable(b)
+#define ww_mutex_base_unlock(b)			mutex_unlock(b)
+#endif
+
 static void ww_test_normal(void)
 {
 	int ret;
@@ -1665,50 +1728,50 @@ static void ww_test_normal(void)
 
 	/* mutex_lock (and indirectly, mutex_lock_nested) */
 	o.ctx = (void *)~0UL;
-	mutex_lock(&o.base);
-	mutex_unlock(&o.base);
+	ww_mutex_base_lock(&o.base);
+	ww_mutex_base_unlock(&o.base);
 	WARN_ON(o.ctx != (void *)~0UL);
 
 	/* mutex_lock_interruptible (and *_nested) */
 	o.ctx = (void *)~0UL;
-	ret = mutex_lock_interruptible(&o.base);
+	ret = ww_mutex_base_lock_interruptible(&o.base);
 	if (!ret)
-		mutex_unlock(&o.base);
+		ww_mutex_base_unlock(&o.base);
 	else
 		WARN_ON(1);
 	WARN_ON(o.ctx != (void *)~0UL);
 
 	/* mutex_lock_killable (and *_nested) */
 	o.ctx = (void *)~0UL;
-	ret = mutex_lock_killable(&o.base);
+	ret = ww_mutex_base_lock_killable(&o.base);
 	if (!ret)
-		mutex_unlock(&o.base);
+		ww_mutex_base_unlock(&o.base);
 	else
 		WARN_ON(1);
 	WARN_ON(o.ctx != (void *)~0UL);
 
 	/* trylock, succeeding */
 	o.ctx = (void *)~0UL;
-	ret = mutex_trylock(&o.base);
+	ret = ww_mutex_base_trylock(&o.base);
 	WARN_ON(!ret);
 	if (ret)
-		mutex_unlock(&o.base);
+		ww_mutex_base_unlock(&o.base);
 	else
 		WARN_ON(1);
 	WARN_ON(o.ctx != (void *)~0UL);
 
 	/* trylock, failing */
 	o.ctx = (void *)~0UL;
-	mutex_lock(&o.base);
-	ret = mutex_trylock(&o.base);
+	ww_mutex_base_lock(&o.base);
+	ret = ww_mutex_base_trylock(&o.base);
 	WARN_ON(ret);
-	mutex_unlock(&o.base);
+	ww_mutex_base_unlock(&o.base);
 	WARN_ON(o.ctx != (void *)~0UL);
 
 	/* nest_lock */
 	o.ctx = (void *)~0UL;
-	mutex_lock_nest_lock(&o.base, &t);
-	mutex_unlock(&o.base);
+	ww_mutex_base_lock_nest_lock(&o.base, &t);
+	ww_mutex_base_unlock(&o.base);
 	WARN_ON(o.ctx != (void *)~0UL);
 }
 
@@ -1721,7 +1784,7 @@ static void ww_test_two_contexts(void)
 static void ww_test_diff_class(void)
 {
 	WWAI(&t);
-#ifdef CONFIG_DEBUG_MUTEXES
+#ifdef DEBUG_WW_MUTEXES
 	t.ww_class = NULL;
 #endif
 	WWL(&o, &t);
@@ -1785,7 +1848,7 @@ static void ww_test_edeadlk_normal(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	o2.ctx = &t2;
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 
@@ -1801,7 +1864,7 @@ static void ww_test_edeadlk_normal(void)
 
 	o2.ctx = NULL;
 	mutex_acquire(&o2.base.dep_map, 0, 1, _THIS_IP_);
-	mutex_unlock(&o2.base);
+	ww_mutex_base_unlock(&o2.base);
 	WWU(&o);
 
 	WWL(&o2, &t);
@@ -1811,7 +1874,7 @@ static void ww_test_edeadlk_normal_slow(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
@@ -1827,7 +1890,7 @@ static void ww_test_edeadlk_normal_slow(void)
 
 	o2.ctx = NULL;
 	mutex_acquire(&o2.base.dep_map, 0, 1, _THIS_IP_);
-	mutex_unlock(&o2.base);
+	ww_mutex_base_unlock(&o2.base);
 	WWU(&o);
 
 	ww_mutex_lock_slow(&o2, &t);
@@ -1837,7 +1900,7 @@ static void ww_test_edeadlk_no_unlock(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	o2.ctx = &t2;
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 
@@ -1853,7 +1916,7 @@ static void ww_test_edeadlk_no_unlock(void)
 
 	o2.ctx = NULL;
 	mutex_acquire(&o2.base.dep_map, 0, 1, _THIS_IP_);
-	mutex_unlock(&o2.base);
+	ww_mutex_base_unlock(&o2.base);
 
 	WWL(&o2, &t);
 }
@@ -1862,7 +1925,7 @@ static void ww_test_edeadlk_no_unlock_slow(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
@@ -1878,7 +1941,7 @@ static void ww_test_edeadlk_no_unlock_slow(void)
 
 	o2.ctx = NULL;
 	mutex_acquire(&o2.base.dep_map, 0, 1, _THIS_IP_);
-	mutex_unlock(&o2.base);
+	ww_mutex_base_unlock(&o2.base);
 
 	ww_mutex_lock_slow(&o2, &t);
 }
@@ -1887,7 +1950,7 @@ static void ww_test_edeadlk_acquire_more(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
@@ -1908,7 +1971,7 @@ static void ww_test_edeadlk_acquire_more_slow(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
@@ -1929,11 +1992,11 @@ static void ww_test_edeadlk_acquire_more_edeadlk(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
-	mutex_lock(&o3.base);
+	ww_mutex_base_lock(&o3.base);
 	mutex_release(&o3.base.dep_map, _THIS_IP_);
 	o3.ctx = &t2;
 
@@ -1955,11 +2018,11 @@ static void ww_test_edeadlk_acquire_more_edeadlk_slow(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
-	mutex_lock(&o3.base);
+	ww_mutex_base_lock(&o3.base);
 	mutex_release(&o3.base.dep_map, _THIS_IP_);
 	o3.ctx = &t2;
 
@@ -1980,7 +2043,7 @@ static void ww_test_edeadlk_acquire_wrong(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
@@ -2005,7 +2068,7 @@ static void ww_test_edeadlk_acquire_wrong_slow(void)
 {
 	int ret;
 
-	mutex_lock(&o2.base);
+	ww_mutex_base_lock(&o2.base);
 	mutex_release(&o2.base.dep_map, _THIS_IP_);
 	o2.ctx = &t2;
 
@@ -2646,8 +2709,8 @@ static void wait_context_tests(void)
 
 static void local_lock_2(void)
 {
-	local_lock_acquire(&local_A);	/* IRQ-ON */
-	local_lock_release(&local_A);
+	local_lock(&local_A);	/* IRQ-ON */
+	local_unlock(&local_A);
 
 	HARDIRQ_ENTER();
 	spin_lock(&lock_A);		/* IN-IRQ */
@@ -2656,18 +2719,18 @@ static void local_lock_2(void)
 
 	HARDIRQ_DISABLE();
 	spin_lock(&lock_A);
-	local_lock_acquire(&local_A);	/* IN-IRQ <-> IRQ-ON cycle, false */
-	local_lock_release(&local_A);
+	local_lock(&local_A);	/* IN-IRQ <-> IRQ-ON cycle, false */
+	local_unlock(&local_A);
 	spin_unlock(&lock_A);
 	HARDIRQ_ENABLE();
 }
 
 static void local_lock_3A(void)
 {
-	local_lock_acquire(&local_A);	/* IRQ-ON */
+	local_lock(&local_A);	/* IRQ-ON */
 	spin_lock(&lock_B);		/* IRQ-ON */
 	spin_unlock(&lock_B);
-	local_lock_release(&local_A);
+	local_unlock(&local_A);
 
 	HARDIRQ_ENTER();
 	spin_lock(&lock_A);		/* IN-IRQ */
@@ -2676,18 +2739,18 @@ static void local_lock_3A(void)
 
 	HARDIRQ_DISABLE();
 	spin_lock(&lock_A);
-	local_lock_acquire(&local_A);	/* IN-IRQ <-> IRQ-ON cycle only if we count local_lock(), false */
-	local_lock_release(&local_A);
+	local_lock(&local_A);	/* IN-IRQ <-> IRQ-ON cycle only if we count local_lock(), false */
+	local_unlock(&local_A);
 	spin_unlock(&lock_A);
 	HARDIRQ_ENABLE();
 }
 
 static void local_lock_3B(void)
 {
-	local_lock_acquire(&local_A);	/* IRQ-ON */
+	local_lock(&local_A);	/* IRQ-ON */
 	spin_lock(&lock_B);		/* IRQ-ON */
 	spin_unlock(&lock_B);
-	local_lock_release(&local_A);
+	local_unlock(&local_A);
 
 	HARDIRQ_ENTER();
 	spin_lock(&lock_A);		/* IN-IRQ */
@@ -2696,8 +2759,8 @@ static void local_lock_3B(void)
 
 	HARDIRQ_DISABLE();
 	spin_lock(&lock_A);
-	local_lock_acquire(&local_A);	/* IN-IRQ <-> IRQ-ON cycle only if we count local_lock(), false */
-	local_lock_release(&local_A);
+	local_lock(&local_A);	/* IN-IRQ <-> IRQ-ON cycle only if we count local_lock(), false */
+	local_unlock(&local_A);
 	spin_unlock(&lock_A);
 	HARDIRQ_ENABLE();
 
@@ -2812,7 +2875,7 @@ void locking_selftest(void)
 	printk("------------------------\n");
 	printk("| Locking API testsuite:\n");
 	printk("----------------------------------------------------------------------------\n");
-	printk("                                 | spin |wlock |rlock |mutex | wsem | rsem |\n");
+	printk("                                 | spin |wlock |rlock |mutex | wsem | rsem |rtmutex\n");
 	printk("  --------------------------------------------------------------------------\n");
 
 	init_shared_classes();
@@ -2885,12 +2948,11 @@ void locking_selftest(void)
 	DO_TESTCASE_6x1RR("rlock W1R2/R2R3/W3W1", W1R2_R2R3_W3W1);
 
 	printk("  --------------------------------------------------------------------------\n");
-
 	/*
 	 * irq-context testcases:
 	 */
 	DO_TESTCASE_2x6("irqs-on + irq-safe-A", irqsafe1);
-	DO_TESTCASE_2x3("sirq-safe-A => hirqs-on", irqsafe2A);
+	NON_RT(DO_TESTCASE_2x3("sirq-safe-A => hirqs-on", irqsafe2A));
 	DO_TESTCASE_2x6("safe-A + irqs-on", irqsafe2B);
 	DO_TESTCASE_6x6("safe-A + unsafe-B #1", irqsafe3);
 	DO_TESTCASE_6x6("safe-A + unsafe-B #2", irqsafe4);
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
index 199ab201d5019..06410209197ae 100644
--- a/lib/nmi_backtrace.c
+++ b/lib/nmi_backtrace.c
@@ -99,7 +99,7 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
 		 * Allow nested NMI backtraces while serializing
 		 * against other CPUs.
 		 */
-		printk_cpu_lock_irqsave(flags);
+		raw_printk_cpu_lock_irqsave(flags);
 		if (!READ_ONCE(backtrace_idle) && regs && cpu_in_idle(instruction_pointer(regs))) {
 			pr_warn("NMI backtrace for cpu %d skipped: idling at %pS\n",
 				cpu, (void *)instruction_pointer(regs));
@@ -110,7 +110,7 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
 			else
 				dump_stack();
 		}
-		printk_cpu_unlock_irqrestore(flags);
+		raw_printk_cpu_unlock_irqrestore(flags);
 		cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
 		return true;
 	}
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index abb3432ed7441..d5e82e4a57ad0 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -828,8 +828,7 @@ static bool sg_miter_get_next_page(struct sg_mapping_iter *miter)
  *   stops @miter.
  *
  * Context:
- *   Don't care if @miter is stopped, or not proceeded yet.
- *   Otherwise, preemption disabled if the SG_MITER_ATOMIC is set.
+ *   Don't care.
  *
  * Returns:
  *   true if @miter contains the valid mapping.  false if end of sg
@@ -865,8 +864,7 @@ EXPORT_SYMBOL(sg_miter_skip);
  *   @miter->addr and @miter->length point to the current mapping.
  *
  * Context:
- *   Preemption disabled if SG_MITER_ATOMIC.  Preemption must stay disabled
- *   till @miter is stopped.  May sleep if !SG_MITER_ATOMIC.
+ *   May sleep if !SG_MITER_ATOMIC.
  *
  * Returns:
  *   true if @miter contains the next mapping.  false if end of sg
@@ -906,8 +904,7 @@ EXPORT_SYMBOL(sg_miter_next);
  *   need to be released during iteration.
  *
  * Context:
- *   Preemption disabled if the SG_MITER_ATOMIC is set.  Don't care
- *   otherwise.
+ *   Don't care otherwise.
  */
 void sg_miter_stop(struct sg_mapping_iter *miter)
 {
@@ -922,7 +919,7 @@ void sg_miter_stop(struct sg_mapping_iter *miter)
 			flush_dcache_page(miter->page);
 
 		if (miter->__flags & SG_MITER_ATOMIC) {
-			WARN_ON_ONCE(preemptible());
+			WARN_ON_ONCE(!pagefault_disabled());
 			kunmap_atomic(miter->addr);
 		} else
 			kunmap(miter->page);
diff --git a/localversion-rt b/localversion-rt
new file mode 100644
index 0000000000000..8de253240c161
--- /dev/null
+++ b/localversion-rt
@@ -0,0 +1 @@
+-rt98
diff --git a/mm/Kconfig b/mm/Kconfig
index 5195a61a09f85..f3855dcb8d44d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -371,7 +371,7 @@ config NOMMU_INITIAL_TRIM_EXCESS
 
 config TRANSPARENT_HUGEPAGE
 	bool "Transparent Hugepage Support"
-	depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
+	depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT
 	select COMPACTION
 	select XARRAY_MULTI
 	help
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9ee63ebab506c..b7bb5b8589e44 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -654,6 +654,35 @@ static u64 flush_next_time;
 
 #define FLUSH_TIME (2UL*HZ)
 
+/*
+ * Accessors to ensure that preemption is disabled on PREEMPT_RT because it can
+ * not rely on this as part of an acquired spinlock_t lock. These functions are
+ * never used in hardirq context on PREEMPT_RT and therefore disabling preemtion
+ * is sufficient.
+ */
+static void memcg_stats_lock(void)
+{
+#ifdef CONFIG_PREEMPT_RT
+      preempt_disable();
+#else
+      VM_BUG_ON(!irqs_disabled());
+#endif
+}
+
+static void __memcg_stats_lock(void)
+{
+#ifdef CONFIG_PREEMPT_RT
+      preempt_disable();
+#endif
+}
+
+static void memcg_stats_unlock(void)
+{
+#ifdef CONFIG_PREEMPT_RT
+      preempt_enable();
+#endif
+}
+
 static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val)
 {
 	unsigned int x;
@@ -737,6 +766,27 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 	memcg = pn->memcg;
 
+	/*
+	 * The caller from rmap relay on disabled preemption becase they never
+	 * update their counter from in-interrupt context. For these two
+	 * counters we check that the update is never performed from an
+	 * interrupt context while other caller need to have disabled interrupt.
+	 */
+	__memcg_stats_lock();
+	if (IS_ENABLED(CONFIG_DEBUG_VM) && !IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		switch (idx) {
+		case NR_ANON_MAPPED:
+		case NR_FILE_MAPPED:
+		case NR_ANON_THPS:
+		case NR_SHMEM_PMDMAPPED:
+		case NR_FILE_PMDMAPPED:
+			WARN_ON_ONCE(!in_task());
+			break;
+		default:
+			WARN_ON_ONCE(!irqs_disabled());
+		}
+	}
+
 	/* Update memcg */
 	__this_cpu_add(memcg->vmstats_percpu->state[idx], val);
 
@@ -744,6 +794,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 	__this_cpu_add(pn->lruvec_stats_percpu->state[idx], val);
 
 	memcg_rstat_updated(memcg, val);
+	memcg_stats_unlock();
 }
 
 /**
@@ -844,8 +895,10 @@ void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
 	if (mem_cgroup_disabled())
 		return;
 
+	memcg_stats_lock();
 	__this_cpu_add(memcg->vmstats_percpu->events[idx], count);
 	memcg_rstat_updated(memcg, count);
+	memcg_stats_unlock();
 }
 
 static unsigned long memcg_events(struct mem_cgroup *memcg, int event)
@@ -909,6 +962,9 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
  */
 static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
 {
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		return;
+
 	/* threshold event is triggered in finer grain than soft limit */
 	if (unlikely(mem_cgroup_event_ratelimit(memcg,
 						MEM_CGROUP_TARGET_THRESH))) {
@@ -2105,39 +2161,37 @@ void unlock_page_memcg(struct page *page)
 }
 EXPORT_SYMBOL(unlock_page_memcg);
 
-struct obj_stock {
+struct memcg_stock_pcp {
+	local_lock_t stock_lock;
+	struct mem_cgroup *cached; /* this never be root cgroup */
+	unsigned int nr_pages;
+
 #ifdef CONFIG_MEMCG_KMEM
 	struct obj_cgroup *cached_objcg;
 	struct pglist_data *cached_pgdat;
 	unsigned int nr_bytes;
 	int nr_slab_reclaimable_b;
 	int nr_slab_unreclaimable_b;
-#else
-	int dummy[0];
 #endif
-};
-
-struct memcg_stock_pcp {
-	struct mem_cgroup *cached; /* this never be root cgroup */
-	unsigned int nr_pages;
-	struct obj_stock task_obj;
-	struct obj_stock irq_obj;
 
 	struct work_struct work;
 	unsigned long flags;
 #define FLUSHING_CACHED_CHARGE	0
 };
-static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
+static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock) = {
+	.stock_lock = INIT_LOCAL_LOCK(stock_lock),
+};
 static DEFINE_MUTEX(percpu_charge_mutex);
 
 #ifdef CONFIG_MEMCG_KMEM
-static void drain_obj_stock(struct obj_stock *stock);
+static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock);
 static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
 				     struct mem_cgroup *root_memcg);
 
 #else
-static inline void drain_obj_stock(struct obj_stock *stock)
+static inline struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock)
 {
+	return NULL;
 }
 static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
 				     struct mem_cgroup *root_memcg)
@@ -2147,41 +2201,6 @@ static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
 #endif
 
 /*
- * Most kmem_cache_alloc() calls are from user context. The irq disable/enable
- * sequence used in this case to access content from object stock is slow.
- * To optimize for user context access, there are now two object stocks for
- * task context and interrupt context access respectively.
- *
- * The task context object stock can be accessed by disabling preemption only
- * which is cheap in non-preempt kernel. The interrupt context object stock
- * can only be accessed after disabling interrupt. User context code can
- * access interrupt object stock, but not vice versa.
- */
-static inline struct obj_stock *get_obj_stock(unsigned long *pflags)
-{
-	struct memcg_stock_pcp *stock;
-
-	if (likely(in_task())) {
-		*pflags = 0UL;
-		preempt_disable();
-		stock = this_cpu_ptr(&memcg_stock);
-		return &stock->task_obj;
-	}
-
-	local_irq_save(*pflags);
-	stock = this_cpu_ptr(&memcg_stock);
-	return &stock->irq_obj;
-}
-
-static inline void put_obj_stock(unsigned long flags)
-{
-	if (likely(in_task()))
-		preempt_enable();
-	else
-		local_irq_restore(flags);
-}
-
-/**
  * consume_stock: Try to consume stocked charge on this cpu.
  * @memcg: memcg to consume from.
  * @nr_pages: how many pages to charge.
@@ -2201,7 +2220,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 	if (nr_pages > MEMCG_CHARGE_BATCH)
 		return ret;
 
-	local_irq_save(flags);
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
 
 	stock = this_cpu_ptr(&memcg_stock);
 	if (memcg == stock->cached && stock->nr_pages >= nr_pages) {
@@ -2209,7 +2228,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 		ret = true;
 	}
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 
 	return ret;
 }
@@ -2238,6 +2257,7 @@ static void drain_stock(struct memcg_stock_pcp *stock)
 static void drain_local_stock(struct work_struct *dummy)
 {
 	struct memcg_stock_pcp *stock;
+	struct obj_cgroup *old = NULL;
 	unsigned long flags;
 
 	/*
@@ -2245,28 +2265,25 @@ static void drain_local_stock(struct work_struct *dummy)
 	 * drain_stock races is that we always operate on local CPU stock
 	 * here with IRQ disabled
 	 */
-	local_irq_save(flags);
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
 
 	stock = this_cpu_ptr(&memcg_stock);
-	drain_obj_stock(&stock->irq_obj);
-	if (in_task())
-		drain_obj_stock(&stock->task_obj);
+	old = drain_obj_stock(stock);
 	drain_stock(stock);
 	clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	if (old)
+		obj_cgroup_put(old);
 }
 
 /*
  * Cache charges(val) to local per_cpu area.
  * This will be consumed by consume_stock() function, later.
  */
-static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
+static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
 	struct memcg_stock_pcp *stock;
-	unsigned long flags;
-
-	local_irq_save(flags);
 
 	stock = this_cpu_ptr(&memcg_stock);
 	if (stock->cached != memcg) { /* reset if necessary */
@@ -2278,8 +2295,15 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 
 	if (stock->nr_pages > MEMCG_CHARGE_BATCH)
 		drain_stock(stock);
+}
 
-	local_irq_restore(flags);
+static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+	unsigned long flags;
+
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
+	__refill_stock(memcg, nr_pages);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 }
 
 /*
@@ -2299,7 +2323,8 @@ static void drain_all_stock(struct mem_cgroup *root_memcg)
 	 * as well as workers from this path always operate on the local
 	 * per-cpu data. CPU up doesn't touch memcg_stock at all.
 	 */
-	curcpu = get_cpu();
+	migrate_disable();
+	curcpu = smp_processor_id();
 	for_each_online_cpu(cpu) {
 		struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
 		struct mem_cgroup *memcg;
@@ -2322,7 +2347,7 @@ static void drain_all_stock(struct mem_cgroup *root_memcg)
 				schedule_work_on(cpu, &stock->work);
 		}
 	}
-	put_cpu();
+	migrate_enable();
 	mutex_unlock(&percpu_charge_mutex);
 }
 
@@ -3088,17 +3113,21 @@ void __memcg_kmem_uncharge_page(struct page *page, int order)
 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 		     enum node_stat_item idx, int nr)
 {
+	struct memcg_stock_pcp *stock;
+	struct obj_cgroup *old = NULL;
 	unsigned long flags;
-	struct obj_stock *stock = get_obj_stock(&flags);
 	int *bytes;
 
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
+	stock = this_cpu_ptr(&memcg_stock);
+
 	/*
 	 * Save vmstat data in stock and skip vmstat array update unless
 	 * accumulating over a page of vmstat data or when pgdat or idx
 	 * changes.
 	 */
 	if (stock->cached_objcg != objcg) {
-		drain_obj_stock(stock);
+		old = drain_obj_stock(stock);
 		obj_cgroup_get(objcg);
 		stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
 				? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
@@ -3142,38 +3171,53 @@ void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 	if (nr)
 		mod_objcg_mlstate(objcg, pgdat, idx, nr);
 
-	put_obj_stock(flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	if (old)
+		obj_cgroup_put(old);
 }
 
 static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes)
 {
+	struct memcg_stock_pcp *stock;
 	unsigned long flags;
-	struct obj_stock *stock = get_obj_stock(&flags);
 	bool ret = false;
 
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
+
+	stock = this_cpu_ptr(&memcg_stock);
 	if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) {
 		stock->nr_bytes -= nr_bytes;
 		ret = true;
 	}
 
-	put_obj_stock(flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 
 	return ret;
 }
 
-static void drain_obj_stock(struct obj_stock *stock)
+static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock)
 {
 	struct obj_cgroup *old = stock->cached_objcg;
 
 	if (!old)
-		return;
+		return NULL;
 
 	if (stock->nr_bytes) {
 		unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT;
 		unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1);
 
-		if (nr_pages)
-			obj_cgroup_uncharge_pages(old, nr_pages);
+		if (nr_pages) {
+			struct mem_cgroup *memcg;
+
+			memcg = get_mem_cgroup_from_objcg(old);
+
+			if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
+				page_counter_uncharge(&memcg->kmem, nr_pages);
+
+			__refill_stock(memcg, nr_pages);
+
+			css_put(&memcg->css);
+		}
 
 		/*
 		 * The leftover is flushed to the centralized per-memcg value.
@@ -3208,8 +3252,12 @@ static void drain_obj_stock(struct obj_stock *stock)
 		stock->cached_pgdat = NULL;
 	}
 
-	obj_cgroup_put(old);
 	stock->cached_objcg = NULL;
+	/*
+	 * The `old' objects needs to be released by the caller via
+	 * obj_cgroup_put() outside of memcg_stock_pcp::stock_lock.
+	 */
+	return old;
 }
 
 static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
@@ -3217,13 +3265,8 @@ static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
 {
 	struct mem_cgroup *memcg;
 
-	if (in_task() && stock->task_obj.cached_objcg) {
-		memcg = obj_cgroup_memcg(stock->task_obj.cached_objcg);
-		if (memcg && mem_cgroup_is_descendant(memcg, root_memcg))
-			return true;
-	}
-	if (stock->irq_obj.cached_objcg) {
-		memcg = obj_cgroup_memcg(stock->irq_obj.cached_objcg);
+	if (stock->cached_objcg) {
+		memcg = obj_cgroup_memcg(stock->cached_objcg);
 		if (memcg && mem_cgroup_is_descendant(memcg, root_memcg))
 			return true;
 	}
@@ -3234,12 +3277,16 @@ static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
 static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
 			     bool allow_uncharge)
 {
+	struct memcg_stock_pcp *stock;
+	struct obj_cgroup *old = NULL;
 	unsigned long flags;
-	struct obj_stock *stock = get_obj_stock(&flags);
 	unsigned int nr_pages = 0;
 
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
+
+	stock = this_cpu_ptr(&memcg_stock);
 	if (stock->cached_objcg != objcg) { /* reset if necessary */
-		drain_obj_stock(stock);
+		old = drain_obj_stock(stock);
 		obj_cgroup_get(objcg);
 		stock->cached_objcg = objcg;
 		stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
@@ -3253,7 +3300,9 @@ static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
 		stock->nr_bytes &= (PAGE_SIZE - 1);
 	}
 
-	put_obj_stock(flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	if (old)
+		obj_cgroup_put(old);
 
 	if (nr_pages)
 		obj_cgroup_uncharge_pages(objcg, nr_pages);
@@ -3820,8 +3869,12 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
 		}
 		break;
 	case RES_SOFT_LIMIT:
-		memcg->soft_limit = nr_pages;
-		ret = 0;
+		if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			ret = -EOPNOTSUPP;
+		} else {
+			memcg->soft_limit = nr_pages;
+			ret = 0;
+		}
 		break;
 	}
 	return ret ?: nbytes;
@@ -4802,6 +4855,9 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
 	char *endp;
 	int ret;
 
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		return -EOPNOTSUPP;
+
 	buf = strstrip(buf);
 
 	efd = simple_strtoul(buf, &endp, 10);
@@ -6913,7 +6969,6 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 	unsigned long nr_pages;
 	struct mem_cgroup *memcg;
 	struct obj_cgroup *objcg;
-	bool use_objcg = PageMemcgKmem(page);
 
 	VM_BUG_ON_PAGE(PageLRU(page), page);
 
@@ -6922,7 +6977,7 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 	 * page memcg or objcg at this point, we have fully
 	 * exclusive access to the page.
 	 */
-	if (use_objcg) {
+	if (PageMemcgKmem(page)) {
 		objcg = __page_objcg(page);
 		/*
 		 * This get matches the put at the end of the function and
@@ -6950,7 +7005,7 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 
 	nr_pages = compound_nr(page);
 
-	if (use_objcg) {
+	if (PageMemcgKmem(page)) {
 		ug->nr_memory += nr_pages;
 		ug->nr_kmem += nr_pages;
 
@@ -7280,8 +7335,9 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
 	 * important here to have the interrupts disabled because it is the
 	 * only synchronisation we have for updating the per-CPU variables.
 	 */
-	VM_BUG_ON(!irqs_disabled());
+	memcg_stats_lock();
 	mem_cgroup_charge_statistics(memcg, page, -nr_entries);
+	memcg_stats_unlock();
 	memcg_check_events(memcg, page);
 
 	css_put(&memcg->css);
diff --git a/mm/memory.c b/mm/memory.c
index 4998b4c490529..7748023ed7127 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5351,7 +5351,7 @@ void __might_fault(const char *file, int line)
 		return;
 	if (pagefault_disabled())
 		return;
-	__might_sleep(file, line, 0);
+	__might_sleep(file, line);
 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP)
 	if (current->mm)
 		might_lock_read(&current->mm->mmap_lock);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cfbfd6309c250..24b1697534a59 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3149,9 +3149,9 @@ static void drain_local_pages_wq(struct work_struct *work)
 	 * cpu which is alright but we also have to make sure to not move to
 	 * a different one.
 	 */
-	preempt_disable();
+	migrate_disable();
 	drain_local_pages(drain->zone);
-	preempt_enable();
+	migrate_enable();
 }
 
 /*
@@ -6499,19 +6499,17 @@ static void __build_all_zonelists(void *data)
 	unsigned long flags;
 
 	/*
-	 * Explicitly disable this CPU's interrupts before taking seqlock
-	 * to prevent any IRQ handler from calling into the page allocator
-	 * (e.g. GFP_ATOMIC) that could hit zonelist_iter_begin and livelock.
+	 * The zonelist_update_seq must be acquired with irqsave because the
+	 * reader can be invoked from IRQ with GFP_ATOMIC.
 	 */
-	local_irq_save(flags);
+	write_seqlock_irqsave(&zonelist_update_seq, flags);
 	/*
-	 * Explicitly disable this CPU's synchronous printk() before taking
-	 * seqlock to prevent any printk() from trying to hold port->lock, for
+	 * Also disable synchronous printk() to prevent any printk() from
+	 * trying to hold port->lock, for
 	 * tty_insert_flip_string_and_push_buffer() on other CPU might be
 	 * calling kmalloc(GFP_ATOMIC | __GFP_NOWARN) with port->lock held.
 	 */
 	printk_deferred_enter();
-	write_seqlock(&zonelist_update_seq);
 
 #ifdef CONFIG_NUMA
 	memset(node_load, 0, sizeof(node_load));
@@ -6544,9 +6542,8 @@ static void __build_all_zonelists(void *data)
 #endif
 	}
 
-	write_sequnlock(&zonelist_update_seq);
 	printk_deferred_exit();
-	local_irq_restore(flags);
+	write_sequnlock_irqrestore(&zonelist_update_seq, flags);
 }
 
 static noinline void __init
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 502f51b86fa37..0f111159e5981 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1925,11 +1925,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 		return ERR_PTR(err);
 	}
 
-	vbq = &get_cpu_var(vmap_block_queue);
+	get_cpu_light();
+	vbq = this_cpu_ptr(&vmap_block_queue);
 	spin_lock(&vbq->lock);
 	list_add_tail_rcu(&vb->free_list, &vbq->free);
 	spin_unlock(&vbq->lock);
-	put_cpu_var(vmap_block_queue);
+	put_cpu_light();
 
 	return vaddr;
 }
@@ -2008,7 +2009,8 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 	order = get_order(size);
 
 	rcu_read_lock();
-	vbq = &get_cpu_var(vmap_block_queue);
+	get_cpu_light();
+	vbq = this_cpu_ptr(&vmap_block_queue);
 	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
 		unsigned long pages_off;
 
@@ -2031,7 +2033,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 		break;
 	}
 
-	put_cpu_var(vmap_block_queue);
+	put_cpu_light();
 	rcu_read_unlock();
 
 	/* Allocate new block if nothing was found */
diff --git a/mm/workingset.c b/mm/workingset.c
index 880d882f3325f..2a9ed5aeb6fa3 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -433,6 +433,8 @@ static struct list_lru shadow_nodes;
 
 void workingset_update_node(struct xa_node *node)
 {
+	struct address_space *mapping;
+
 	/*
 	 * Track non-empty nodes that contain only shadow entries;
 	 * unlink those that contain pages or are being freed.
@@ -441,7 +443,8 @@ void workingset_update_node(struct xa_node *node)
 	 * already where they should be. The list_empty() test is safe
 	 * as node->private_list is protected by the i_pages lock.
 	 */
-	VM_WARN_ON_ONCE(!irqs_disabled());  /* For __inc_lruvec_page_state */
+	mapping = container_of(node->array, struct address_space, i_pages);
+	lockdep_assert_held(&mapping->i_pages.xa_lock);
 
 	if (node->count && node->count == node->nr_values) {
 		if (list_empty(&node->private_list)) {
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index fd01f6922874b..f85c350474112 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -57,6 +57,7 @@
 #include <linux/wait.h>
 #include <linux/pagemap.h>
 #include <linux/fs.h>
+#include <linux/local_lock.h>
 
 #define ZSPAGE_MAGIC	0x58
 
@@ -77,6 +78,20 @@
 
 #define ZS_HANDLE_SIZE (sizeof(unsigned long))
 
+#ifdef CONFIG_PREEMPT_RT
+
+struct zsmalloc_handle {
+	unsigned long addr;
+	spinlock_t lock;
+};
+
+#define ZS_HANDLE_ALLOC_SIZE (sizeof(struct zsmalloc_handle))
+
+#else
+
+#define ZS_HANDLE_ALLOC_SIZE (sizeof(unsigned long))
+#endif
+
 /*
  * Object location (<PFN>, <obj_idx>) is encoded as
  * a single (unsigned long) handle value.
@@ -292,6 +307,7 @@ struct zspage {
 };
 
 struct mapping_area {
+	local_lock_t lock;
 	char *vm_buf; /* copy buffer for objects that span pages */
 	char *vm_addr; /* address of kmap_atomic()'ed pages */
 	enum zs_mapmode vm_mm; /* mapping mode */
@@ -321,7 +337,7 @@ static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {}
 
 static int create_cache(struct zs_pool *pool)
 {
-	pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE,
+	pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_ALLOC_SIZE,
 					0, 0, NULL);
 	if (!pool->handle_cachep)
 		return 1;
@@ -345,10 +361,27 @@ static void destroy_cache(struct zs_pool *pool)
 
 static unsigned long cache_alloc_handle(struct zs_pool *pool, gfp_t gfp)
 {
-	return (unsigned long)kmem_cache_alloc(pool->handle_cachep,
-			gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE));
+	void *p;
+
+	p = kmem_cache_alloc(pool->handle_cachep,
+			     gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE));
+#ifdef CONFIG_PREEMPT_RT
+	if (p) {
+		struct zsmalloc_handle *zh = p;
+
+		spin_lock_init(&zh->lock);
+	}
+#endif
+	return (unsigned long)p;
 }
 
+#ifdef CONFIG_PREEMPT_RT
+static struct zsmalloc_handle *zs_get_pure_handle(unsigned long handle)
+{
+	return (void *)(handle & ~((1 << OBJ_TAG_BITS) - 1));
+}
+#endif
+
 static void cache_free_handle(struct zs_pool *pool, unsigned long handle)
 {
 	kmem_cache_free(pool->handle_cachep, (void *)handle);
@@ -367,12 +400,18 @@ static void cache_free_zspage(struct zs_pool *pool, struct zspage *zspage)
 
 static void record_obj(unsigned long handle, unsigned long obj)
 {
+#ifdef CONFIG_PREEMPT_RT
+	struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
+
+	WRITE_ONCE(zh->addr, obj);
+#else
 	/*
 	 * lsb of @obj represents handle lock while other bits
 	 * represent object value the handle is pointing so
 	 * updating shouldn't do store tearing.
 	 */
 	WRITE_ONCE(*(unsigned long *)handle, obj);
+#endif
 }
 
 /* zpool driver */
@@ -454,7 +493,9 @@ MODULE_ALIAS("zpool-zsmalloc");
 #endif /* CONFIG_ZPOOL */
 
 /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
-static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
+static DEFINE_PER_CPU(struct mapping_area, zs_map_area) = {
+	.lock	= INIT_LOCAL_LOCK(lock),
+};
 
 static bool is_zspage_isolated(struct zspage *zspage)
 {
@@ -861,7 +902,13 @@ static unsigned long location_to_obj(struct page *page, unsigned int obj_idx)
 
 static unsigned long handle_to_obj(unsigned long handle)
 {
+#ifdef CONFIG_PREEMPT_RT
+	struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
+
+	return zh->addr;
+#else
 	return *(unsigned long *)handle;
+#endif
 }
 
 static unsigned long obj_to_head(struct page *page, void *obj)
@@ -875,22 +922,46 @@ static unsigned long obj_to_head(struct page *page, void *obj)
 
 static inline int testpin_tag(unsigned long handle)
 {
+#ifdef CONFIG_PREEMPT_RT
+	struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
+
+	return spin_is_locked(&zh->lock);
+#else
 	return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle);
+#endif
 }
 
 static inline int trypin_tag(unsigned long handle)
 {
+#ifdef CONFIG_PREEMPT_RT
+	struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
+
+	return spin_trylock(&zh->lock);
+#else
 	return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle);
+#endif
 }
 
 static void pin_tag(unsigned long handle) __acquires(bitlock)
 {
+#ifdef CONFIG_PREEMPT_RT
+	struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
+
+	return spin_lock(&zh->lock);
+#else
 	bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle);
+#endif
 }
 
 static void unpin_tag(unsigned long handle) __releases(bitlock)
 {
+#ifdef CONFIG_PREEMPT_RT
+	struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
+
+	return spin_unlock(&zh->lock);
+#else
 	bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle);
+#endif
 }
 
 static void reset_page(struct page *page)
@@ -1276,7 +1347,8 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
 	class = pool->size_class[class_idx];
 	off = (class->size * obj_idx) & ~PAGE_MASK;
 
-	area = &get_cpu_var(zs_map_area);
+	local_lock(&zs_map_area.lock);
+	area = this_cpu_ptr(&zs_map_area);
 	area->vm_mm = mm;
 	if (off + class->size <= PAGE_SIZE) {
 		/* this object is contained entirely within a page */
@@ -1330,7 +1402,7 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
 
 		__zs_unmap_object(area, pages, off, class->size);
 	}
-	put_cpu_var(zs_map_area);
+	local_unlock(&zs_map_area.lock);
 
 	migrate_read_unlock(zspage);
 	unpin_tag(handle);
diff --git a/net/Kconfig b/net/Kconfig
index 76a3385943e50..bd7386eede235 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -292,7 +292,7 @@ config CGROUP_NET_CLASSID
 
 config NET_RX_BUSY_POLL
 	bool
-	default y
+	default y if !PREEMPT_RT
 
 config BQL
 	bool
diff --git a/net/core/dev.c b/net/core/dev.c
index 4aa21422e1d0a..5a721f54833f3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -225,14 +225,14 @@ static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
 static inline void rps_lock(struct softnet_data *sd)
 {
 #ifdef CONFIG_RPS
-	spin_lock(&sd->input_pkt_queue.lock);
+	raw_spin_lock(&sd->input_pkt_queue.raw_lock);
 #endif
 }
 
 static inline void rps_unlock(struct softnet_data *sd)
 {
 #ifdef CONFIG_RPS
-	spin_unlock(&sd->input_pkt_queue.lock);
+	raw_spin_unlock(&sd->input_pkt_queue.raw_lock);
 #endif
 }
 
@@ -3110,6 +3110,7 @@ static void __netif_reschedule(struct Qdisc *q)
 	sd->output_queue_tailp = &q->next_sched;
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 
 void __netif_schedule(struct Qdisc *q)
@@ -3172,6 +3173,7 @@ void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
 	__this_cpu_write(softnet_data.completion_queue, skb);
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 EXPORT_SYMBOL(__dev_kfree_skb_irq);
 
@@ -3917,7 +3919,11 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 	 * This permits qdisc->running owner to get the lock more
 	 * often and dequeue packets faster.
 	 */
+#ifdef CONFIG_PREEMPT_RT
+	contended = true;
+#else
 	contended = qdisc_is_running(q);
+#endif
 	if (unlikely(contended))
 		spin_lock(&q->busylock);
 
@@ -4758,6 +4764,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
 	rps_unlock(sd);
 
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 
 	atomic_long_inc(&skb->dev->rx_dropped);
 	kfree_skb(skb);
@@ -4998,7 +5005,7 @@ static int netif_rx_internal(struct sk_buff *skb)
 		struct rps_dev_flow voidflow, *rflow = &voidflow;
 		int cpu;
 
-		preempt_disable();
+		migrate_disable();
 		rcu_read_lock();
 
 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -5008,14 +5015,14 @@ static int netif_rx_internal(struct sk_buff *skb)
 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
 
 		rcu_read_unlock();
-		preempt_enable();
+		migrate_enable();
 	} else
 #endif
 	{
 		unsigned int qtail;
 
-		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
-		put_cpu();
+		ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail);
+		put_cpu_light();
 	}
 	return ret;
 }
@@ -5054,11 +5061,9 @@ int netif_rx_ni(struct sk_buff *skb)
 
 	trace_netif_rx_ni_entry(skb);
 
-	preempt_disable();
+	local_bh_disable();
 	err = netif_rx_internal(skb);
-	if (local_softirq_pending())
-		do_softirq();
-	preempt_enable();
+	local_bh_enable();
 	trace_netif_rx_ni_exit(err);
 
 	return err;
@@ -6502,12 +6507,14 @@ static void net_rps_action_and_irq_enable(struct softnet_data *sd)
 		sd->rps_ipi_list = NULL;
 
 		local_irq_enable();
+		preempt_check_resched_rt();
 
 		/* Send pending IPI's to kick RPS processing on remote cpus. */
 		net_rps_send_ipi(remsd);
 	} else
 #endif
 		local_irq_enable();
+	preempt_check_resched_rt();
 }
 
 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
@@ -6585,6 +6592,7 @@ void __napi_schedule(struct napi_struct *n)
 	local_irq_save(flags);
 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 EXPORT_SYMBOL(__napi_schedule);
 
@@ -11413,6 +11421,7 @@ static int dev_cpu_dead(unsigned int oldcpu)
 
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_enable();
+	preempt_check_resched_rt();
 
 #ifdef CONFIG_RPS
 	remsd = oldsd->rps_ipi_list;
@@ -11426,7 +11435,7 @@ static int dev_cpu_dead(unsigned int oldcpu)
 		netif_rx_ni(skb);
 		input_queue_head_incr(oldsd);
 	}
-	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
+	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
 		netif_rx_ni(skb);
 		input_queue_head_incr(oldsd);
 	}
@@ -11741,7 +11750,7 @@ static int __init net_dev_init(void)
 
 		INIT_WORK(flush, flush_backlog);
 
-		skb_queue_head_init(&sd->input_pkt_queue);
+		skb_queue_head_init_raw(&sd->input_pkt_queue);
 		skb_queue_head_init(&sd->process_queue);
 #ifdef CONFIG_XFRM_OFFLOAD
 		skb_queue_head_init(&sd->xfrm_backlog);
diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c
index 8e582e29a41e3..4fcbdd71c59fa 100644
--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -40,10 +40,10 @@
  */
 
 struct net_rate_estimator {
-	struct gnet_stats_basic_packed	*bstats;
+	struct gnet_stats_basic_sync	*bstats;
 	spinlock_t		*stats_lock;
-	seqcount_t		*running;
-	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
+	bool			running;
+	struct gnet_stats_basic_sync __percpu *cpu_bstats;
 	u8			ewma_log;
 	u8			intvl_log; /* period : (250ms << intvl_log) */
 
@@ -60,13 +60,13 @@ struct net_rate_estimator {
 };
 
 static void est_fetch_counters(struct net_rate_estimator *e,
-			       struct gnet_stats_basic_packed *b)
+			       struct gnet_stats_basic_sync *b)
 {
-	memset(b, 0, sizeof(*b));
+	gnet_stats_basic_sync_init(b);
 	if (e->stats_lock)
 		spin_lock(e->stats_lock);
 
-	__gnet_stats_copy_basic(e->running, b, e->cpu_bstats, e->bstats);
+	gnet_stats_add_basic(b, e->cpu_bstats, e->bstats, e->running);
 
 	if (e->stats_lock)
 		spin_unlock(e->stats_lock);
@@ -76,14 +76,18 @@ static void est_fetch_counters(struct net_rate_estimator *e,
 static void est_timer(struct timer_list *t)
 {
 	struct net_rate_estimator *est = from_timer(est, t, timer);
-	struct gnet_stats_basic_packed b;
+	struct gnet_stats_basic_sync b;
+	u64 b_bytes, b_packets;
 	u64 rate, brate;
 
 	est_fetch_counters(est, &b);
-	brate = (b.bytes - est->last_bytes) << (10 - est->intvl_log);
+	b_bytes = u64_stats_read(&b.bytes);
+	b_packets = u64_stats_read(&b.packets);
+
+	brate = (b_bytes - est->last_bytes) << (10 - est->intvl_log);
 	brate = (brate >> est->ewma_log) - (est->avbps >> est->ewma_log);
 
-	rate = (b.packets - est->last_packets) << (10 - est->intvl_log);
+	rate = (b_packets - est->last_packets) << (10 - est->intvl_log);
 	rate = (rate >> est->ewma_log) - (est->avpps >> est->ewma_log);
 
 	write_seqcount_begin(&est->seq);
@@ -91,8 +95,8 @@ static void est_timer(struct timer_list *t)
 	est->avpps += rate;
 	write_seqcount_end(&est->seq);
 
-	est->last_bytes = b.bytes;
-	est->last_packets = b.packets;
+	est->last_bytes = b_bytes;
+	est->last_packets = b_packets;
 
 	est->next_jiffies += ((HZ/4) << est->intvl_log);
 
@@ -109,7 +113,9 @@ static void est_timer(struct timer_list *t)
  * @cpu_bstats: bstats per cpu
  * @rate_est: rate estimator statistics
  * @lock: lock for statistics and control path
- * @running: qdisc running seqcount
+ * @running: true if @bstats represents a running qdisc, thus @bstats'
+ *           internal values might change during basic reads. Only used
+ *           if @bstats_cpu is NULL
  * @opt: rate estimator configuration TLV
  *
  * Creates a new rate estimator with &bstats as source and &rate_est
@@ -121,16 +127,16 @@ static void est_timer(struct timer_list *t)
  * Returns 0 on success or a negative error code.
  *
  */
-int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
-		      struct gnet_stats_basic_cpu __percpu *cpu_bstats,
+int gen_new_estimator(struct gnet_stats_basic_sync *bstats,
+		      struct gnet_stats_basic_sync __percpu *cpu_bstats,
 		      struct net_rate_estimator __rcu **rate_est,
 		      spinlock_t *lock,
-		      seqcount_t *running,
+		      bool running,
 		      struct nlattr *opt)
 {
 	struct gnet_estimator *parm = nla_data(opt);
 	struct net_rate_estimator *old, *est;
-	struct gnet_stats_basic_packed b;
+	struct gnet_stats_basic_sync b;
 	int intvl_log;
 
 	if (nla_len(opt) < sizeof(*parm))
@@ -164,8 +170,8 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
 	est_fetch_counters(est, &b);
 	if (lock)
 		local_bh_enable();
-	est->last_bytes = b.bytes;
-	est->last_packets = b.packets;
+	est->last_bytes = u64_stats_read(&b.bytes);
+	est->last_packets = u64_stats_read(&b.packets);
 
 	if (lock)
 		spin_lock_bh(lock);
@@ -214,7 +220,9 @@ EXPORT_SYMBOL(gen_kill_estimator);
  * @cpu_bstats: bstats per cpu
  * @rate_est: rate estimator statistics
  * @lock: lock for statistics and control path
- * @running: qdisc running seqcount (might be NULL)
+ * @running: true if @bstats represents a running qdisc, thus @bstats'
+ *           internal values might change during basic reads. Only used
+ *           if @cpu_bstats is NULL
  * @opt: rate estimator configuration TLV
  *
  * Replaces the configuration of a rate estimator by calling
@@ -222,11 +230,11 @@ EXPORT_SYMBOL(gen_kill_estimator);
  *
  * Returns 0 on success or a negative error code.
  */
-int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
-			  struct gnet_stats_basic_cpu __percpu *cpu_bstats,
+int gen_replace_estimator(struct gnet_stats_basic_sync *bstats,
+			  struct gnet_stats_basic_sync __percpu *cpu_bstats,
 			  struct net_rate_estimator __rcu **rate_est,
 			  spinlock_t *lock,
-			  seqcount_t *running, struct nlattr *opt)
+			  bool running, struct nlattr *opt)
 {
 	return gen_new_estimator(bstats, cpu_bstats, rate_est,
 				 lock, running, opt);
diff --git a/net/core/gen_stats.c b/net/core/gen_stats.c
index e491b083b3485..a10335b4ba2d0 100644
--- a/net/core/gen_stats.c
+++ b/net/core/gen_stats.c
@@ -18,7 +18,7 @@
 #include <linux/gen_stats.h>
 #include <net/netlink.h>
 #include <net/gen_stats.h>
-
+#include <net/sch_generic.h>
 
 static inline int
 gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size, int padattr)
@@ -114,63 +114,112 @@ gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
 }
 EXPORT_SYMBOL(gnet_stats_start_copy);
 
-static void
-__gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
-			    struct gnet_stats_basic_cpu __percpu *cpu)
+/* Must not be inlined, due to u64_stats seqcount_t lockdep key */
+void gnet_stats_basic_sync_init(struct gnet_stats_basic_sync *b)
 {
+	u64_stats_set(&b->bytes, 0);
+	u64_stats_set(&b->packets, 0);
+	u64_stats_init(&b->syncp);
+}
+EXPORT_SYMBOL(gnet_stats_basic_sync_init);
+
+static void gnet_stats_add_basic_cpu(struct gnet_stats_basic_sync *bstats,
+				     struct gnet_stats_basic_sync __percpu *cpu)
+{
+	u64 t_bytes = 0, t_packets = 0;
 	int i;
 
 	for_each_possible_cpu(i) {
-		struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
+		struct gnet_stats_basic_sync *bcpu = per_cpu_ptr(cpu, i);
 		unsigned int start;
 		u64 bytes, packets;
 
 		do {
 			start = u64_stats_fetch_begin_irq(&bcpu->syncp);
-			bytes = bcpu->bstats.bytes;
-			packets = bcpu->bstats.packets;
+			bytes = u64_stats_read(&bcpu->bytes);
+			packets = u64_stats_read(&bcpu->packets);
 		} while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
 
-		bstats->bytes += bytes;
-		bstats->packets += packets;
+		t_bytes += bytes;
+		t_packets += packets;
+	}
+	_bstats_update(bstats, t_bytes, t_packets);
+}
+
+void gnet_stats_add_basic(struct gnet_stats_basic_sync *bstats,
+			  struct gnet_stats_basic_sync __percpu *cpu,
+			  struct gnet_stats_basic_sync *b, bool running)
+{
+	unsigned int start;
+	u64 bytes = 0;
+	u64 packets = 0;
+
+	WARN_ON_ONCE((cpu || running) && in_hardirq());
+
+	if (cpu) {
+		gnet_stats_add_basic_cpu(bstats, cpu);
+		return;
 	}
+	do {
+		if (running)
+			start = u64_stats_fetch_begin_irq(&b->syncp);
+		bytes = u64_stats_read(&b->bytes);
+		packets = u64_stats_read(&b->packets);
+	} while (running && u64_stats_fetch_retry_irq(&b->syncp, start));
+
+	_bstats_update(bstats, bytes, packets);
 }
+EXPORT_SYMBOL(gnet_stats_add_basic);
 
-void
-__gnet_stats_copy_basic(const seqcount_t *running,
-			struct gnet_stats_basic_packed *bstats,
-			struct gnet_stats_basic_cpu __percpu *cpu,
-			struct gnet_stats_basic_packed *b)
+static void gnet_stats_read_basic(u64 *ret_bytes, u64 *ret_packets,
+				  struct gnet_stats_basic_sync __percpu *cpu,
+				  struct gnet_stats_basic_sync *b, bool running)
 {
-	unsigned int seq;
+	unsigned int start;
 
 	if (cpu) {
-		__gnet_stats_copy_basic_cpu(bstats, cpu);
+		u64 t_bytes = 0, t_packets = 0;
+		int i;
+
+		for_each_possible_cpu(i) {
+			struct gnet_stats_basic_sync *bcpu = per_cpu_ptr(cpu, i);
+			unsigned int start;
+			u64 bytes, packets;
+
+			do {
+				start = u64_stats_fetch_begin_irq(&bcpu->syncp);
+				bytes = u64_stats_read(&bcpu->bytes);
+				packets = u64_stats_read(&bcpu->packets);
+			} while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
+
+			t_bytes += bytes;
+			t_packets += packets;
+		}
+		*ret_bytes = t_bytes;
+		*ret_packets = t_packets;
 		return;
 	}
 	do {
 		if (running)
-			seq = read_seqcount_begin(running);
-		bstats->bytes = b->bytes;
-		bstats->packets = b->packets;
-	} while (running && read_seqcount_retry(running, seq));
+			start = u64_stats_fetch_begin_irq(&b->syncp);
+		*ret_bytes = u64_stats_read(&b->bytes);
+		*ret_packets = u64_stats_read(&b->packets);
+	} while (running && u64_stats_fetch_retry_irq(&b->syncp, start));
 }
-EXPORT_SYMBOL(__gnet_stats_copy_basic);
 
 static int
-___gnet_stats_copy_basic(const seqcount_t *running,
-			 struct gnet_dump *d,
-			 struct gnet_stats_basic_cpu __percpu *cpu,
-			 struct gnet_stats_basic_packed *b,
-			 int type)
+___gnet_stats_copy_basic(struct gnet_dump *d,
+			 struct gnet_stats_basic_sync __percpu *cpu,
+			 struct gnet_stats_basic_sync *b,
+			 int type, bool running)
 {
-	struct gnet_stats_basic_packed bstats = {0};
+	u64 bstats_bytes, bstats_packets;
 
-	__gnet_stats_copy_basic(running, &bstats, cpu, b);
+	gnet_stats_read_basic(&bstats_bytes, &bstats_packets, cpu, b, running);
 
 	if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
-		d->tc_stats.bytes = bstats.bytes;
-		d->tc_stats.packets = bstats.packets;
+		d->tc_stats.bytes = bstats_bytes;
+		d->tc_stats.packets = bstats_packets;
 	}
 
 	if (d->tail) {
@@ -178,24 +227,28 @@ ___gnet_stats_copy_basic(const seqcount_t *running,
 		int res;
 
 		memset(&sb, 0, sizeof(sb));
-		sb.bytes = bstats.bytes;
-		sb.packets = bstats.packets;
+		sb.bytes = bstats_bytes;
+		sb.packets = bstats_packets;
 		res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
-		if (res < 0 || sb.packets == bstats.packets)
+		if (res < 0 || sb.packets == bstats_packets)
 			return res;
 		/* emit 64bit stats only if needed */
-		return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats.packets,
-				       sizeof(bstats.packets), TCA_STATS_PAD);
+		return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats_packets,
+				       sizeof(bstats_packets), TCA_STATS_PAD);
 	}
 	return 0;
 }
 
 /**
  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
- * @running: seqcount_t pointer
  * @d: dumping handle
  * @cpu: copy statistic per cpu
  * @b: basic statistics
+ * @running: true if @b represents a running qdisc, thus @b's
+ *           internal values might change during basic reads.
+ *           Only used if @cpu is NULL
+ *
+ * Context: task; must not be run from IRQ or BH contexts
  *
  * Appends the basic statistics to the top level TLV created by
  * gnet_stats_start_copy().
@@ -204,22 +257,25 @@ ___gnet_stats_copy_basic(const seqcount_t *running,
  * if the room in the socket buffer was not sufficient.
  */
 int
-gnet_stats_copy_basic(const seqcount_t *running,
-		      struct gnet_dump *d,
-		      struct gnet_stats_basic_cpu __percpu *cpu,
-		      struct gnet_stats_basic_packed *b)
+gnet_stats_copy_basic(struct gnet_dump *d,
+		      struct gnet_stats_basic_sync __percpu *cpu,
+		      struct gnet_stats_basic_sync *b,
+		      bool running)
 {
-	return ___gnet_stats_copy_basic(running, d, cpu, b,
-					TCA_STATS_BASIC);
+	return ___gnet_stats_copy_basic(d, cpu, b, TCA_STATS_BASIC, running);
 }
 EXPORT_SYMBOL(gnet_stats_copy_basic);
 
 /**
  * gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
- * @running: seqcount_t pointer
  * @d: dumping handle
  * @cpu: copy statistic per cpu
  * @b: basic statistics
+ * @running: true if @b represents a running qdisc, thus @b's
+ *           internal values might change during basic reads.
+ *           Only used if @cpu is NULL
+ *
+ * Context: task; must not be run from IRQ or BH contexts
  *
  * Appends the basic statistics to the top level TLV created by
  * gnet_stats_start_copy().
@@ -228,13 +284,12 @@ EXPORT_SYMBOL(gnet_stats_copy_basic);
  * if the room in the socket buffer was not sufficient.
  */
 int
-gnet_stats_copy_basic_hw(const seqcount_t *running,
-			 struct gnet_dump *d,
-			 struct gnet_stats_basic_cpu __percpu *cpu,
-			 struct gnet_stats_basic_packed *b)
+gnet_stats_copy_basic_hw(struct gnet_dump *d,
+			 struct gnet_stats_basic_sync __percpu *cpu,
+			 struct gnet_stats_basic_sync *b,
+			 bool running)
 {
-	return ___gnet_stats_copy_basic(running, d, cpu, b,
-					TCA_STATS_BASIC_HW);
+	return ___gnet_stats_copy_basic(d, cpu, b, TCA_STATS_BASIC_HW, running);
 }
 EXPORT_SYMBOL(gnet_stats_copy_basic_hw);
 
@@ -282,16 +337,15 @@ gnet_stats_copy_rate_est(struct gnet_dump *d,
 }
 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 
-static void
-__gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
-			    const struct gnet_stats_queue __percpu *q)
+static void gnet_stats_add_queue_cpu(struct gnet_stats_queue *qstats,
+				     const struct gnet_stats_queue __percpu *q)
 {
 	int i;
 
 	for_each_possible_cpu(i) {
 		const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
 
-		qstats->qlen = 0;
+		qstats->qlen += qcpu->backlog;
 		qstats->backlog += qcpu->backlog;
 		qstats->drops += qcpu->drops;
 		qstats->requeues += qcpu->requeues;
@@ -299,24 +353,21 @@ __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 	}
 }
 
-void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
-			     const struct gnet_stats_queue __percpu *cpu,
-			     const struct gnet_stats_queue *q,
-			     __u32 qlen)
+void gnet_stats_add_queue(struct gnet_stats_queue *qstats,
+			  const struct gnet_stats_queue __percpu *cpu,
+			  const struct gnet_stats_queue *q)
 {
 	if (cpu) {
-		__gnet_stats_copy_queue_cpu(qstats, cpu);
+		gnet_stats_add_queue_cpu(qstats, cpu);
 	} else {
-		qstats->qlen = q->qlen;
-		qstats->backlog = q->backlog;
-		qstats->drops = q->drops;
-		qstats->requeues = q->requeues;
-		qstats->overlimits = q->overlimits;
+		qstats->qlen += q->qlen;
+		qstats->backlog += q->backlog;
+		qstats->drops += q->drops;
+		qstats->requeues += q->requeues;
+		qstats->overlimits += q->overlimits;
 	}
-
-	qstats->qlen = qlen;
 }
-EXPORT_SYMBOL(__gnet_stats_copy_queue);
+EXPORT_SYMBOL(gnet_stats_add_queue);
 
 /**
  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
@@ -339,7 +390,8 @@ gnet_stats_copy_queue(struct gnet_dump *d,
 {
 	struct gnet_stats_queue qstats = {0};
 
-	__gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
+	gnet_stats_add_queue(&qstats, cpu_q, q);
+	qstats.qlen = qlen;
 
 	if (d->compat_tc_stats) {
 		d->tc_stats.drops = qstats.drops;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 43b8995142e2e..05d31f0b9a0e4 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1425,7 +1425,18 @@ static struct rt6_info *rt6_make_pcpu_route(struct net *net,
 
 	p = this_cpu_ptr(res->nh->rt6i_pcpu);
 	prev = cmpxchg(p, NULL, pcpu_rt);
-	BUG_ON(prev);
+	if (unlikely(prev)) {
+		/*
+		 * Another task on this CPU already installed a pcpu_rt.
+		 * This can happen on PREEMPT_RT where preemption is possible.
+		 * Free our allocation and return the existing one.
+		 */
+		WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT_RT));
+
+		dst_dev_put(&pcpu_rt->dst);
+		dst_release(&pcpu_rt->dst);
+		return prev;
+	}
 
 	if (res->f6i->fib6_destroying) {
 		struct fib6_info *from;
diff --git a/net/netfilter/nft_counter.c b/net/netfilter/nft_counter.c
index 30b24d002c3d8..e387b6610aaf2 100644
--- a/net/netfilter/nft_counter.c
+++ b/net/netfilter/nft_counter.c
@@ -8,7 +8,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/seqlock.h>
+#include <linux/u64_stats_sync.h>
 #include <linux/netlink.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter/nf_tables.h>
@@ -16,6 +16,11 @@
 #include <net/netfilter/nf_tables_offload.h>
 
 struct nft_counter {
+	u64_stats_t	bytes;
+	u64_stats_t	packets;
+};
+
+struct nft_counter_tot {
 	s64		bytes;
 	s64		packets;
 };
@@ -24,25 +29,24 @@ struct nft_counter_percpu_priv {
 	struct nft_counter __percpu *counter;
 };
 
-static DEFINE_PER_CPU(seqcount_t, nft_counter_seq);
+static DEFINE_PER_CPU(struct u64_stats_sync, nft_counter_sync);
 
 static inline void nft_counter_do_eval(struct nft_counter_percpu_priv *priv,
 				       struct nft_regs *regs,
 				       const struct nft_pktinfo *pkt)
 {
+	struct u64_stats_sync *nft_sync;
 	struct nft_counter *this_cpu;
-	seqcount_t *myseq;
 
 	local_bh_disable();
 	this_cpu = this_cpu_ptr(priv->counter);
-	myseq = this_cpu_ptr(&nft_counter_seq);
+	nft_sync = this_cpu_ptr(&nft_counter_sync);
 
-	write_seqcount_begin(myseq);
+	u64_stats_update_begin(nft_sync);
+	u64_stats_add(&this_cpu->bytes, pkt->skb->len);
+	u64_stats_inc(&this_cpu->packets);
+	u64_stats_update_end(nft_sync);
 
-	this_cpu->bytes += pkt->skb->len;
-	this_cpu->packets++;
-
-	write_seqcount_end(myseq);
 	local_bh_enable();
 }
 
@@ -65,17 +69,16 @@ static int nft_counter_do_init(const struct nlattr * const tb[],
 	if (cpu_stats == NULL)
 		return -ENOMEM;
 
-	preempt_disable();
-	this_cpu = this_cpu_ptr(cpu_stats);
+	this_cpu = raw_cpu_ptr(cpu_stats);
 	if (tb[NFTA_COUNTER_PACKETS]) {
-	        this_cpu->packets =
-			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
+		u64_stats_set(&this_cpu->packets,
+			      be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS])));
 	}
 	if (tb[NFTA_COUNTER_BYTES]) {
-		this_cpu->bytes =
-			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
+		u64_stats_set(&this_cpu->bytes,
+			      be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES])));
 	}
-	preempt_enable();
+
 	priv->counter = cpu_stats;
 	return 0;
 }
@@ -103,40 +106,41 @@ static void nft_counter_obj_destroy(const struct nft_ctx *ctx,
 }
 
 static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
-			      struct nft_counter *total)
+			      struct nft_counter_tot *total)
 {
+	struct u64_stats_sync *nft_sync;
 	struct nft_counter *this_cpu;
-	seqcount_t *myseq;
 
 	local_bh_disable();
 	this_cpu = this_cpu_ptr(priv->counter);
-	myseq = this_cpu_ptr(&nft_counter_seq);
+	nft_sync = this_cpu_ptr(&nft_counter_sync);
+
+	u64_stats_update_begin(nft_sync);
+	u64_stats_add(&this_cpu->packets, -total->packets);
+	u64_stats_add(&this_cpu->bytes, -total->bytes);
+	u64_stats_update_end(nft_sync);
 
-	write_seqcount_begin(myseq);
-	this_cpu->packets -= total->packets;
-	this_cpu->bytes -= total->bytes;
-	write_seqcount_end(myseq);
 	local_bh_enable();
 }
 
 static void nft_counter_fetch(struct nft_counter_percpu_priv *priv,
-			      struct nft_counter *total)
+			      struct nft_counter_tot *total)
 {
 	struct nft_counter *this_cpu;
-	const seqcount_t *myseq;
 	u64 bytes, packets;
 	unsigned int seq;
 	int cpu;
 
 	memset(total, 0, sizeof(*total));
 	for_each_possible_cpu(cpu) {
-		myseq = per_cpu_ptr(&nft_counter_seq, cpu);
+		struct u64_stats_sync *nft_sync = per_cpu_ptr(&nft_counter_sync, cpu);
+
 		this_cpu = per_cpu_ptr(priv->counter, cpu);
 		do {
-			seq	= read_seqcount_begin(myseq);
-			bytes	= this_cpu->bytes;
-			packets	= this_cpu->packets;
-		} while (read_seqcount_retry(myseq, seq));
+			seq	= u64_stats_fetch_begin(nft_sync);
+			bytes	= u64_stats_read(&this_cpu->bytes);
+			packets	= u64_stats_read(&this_cpu->packets);
+		} while (u64_stats_fetch_retry(nft_sync, seq));
 
 		total->bytes	+= bytes;
 		total->packets	+= packets;
@@ -147,7 +151,7 @@ static int nft_counter_do_dump(struct sk_buff *skb,
 			       struct nft_counter_percpu_priv *priv,
 			       bool reset)
 {
-	struct nft_counter total;
+	struct nft_counter_tot total;
 
 	nft_counter_fetch(priv, &total);
 
@@ -236,7 +240,7 @@ static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src, g
 	struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
 	struct nft_counter __percpu *cpu_stats;
 	struct nft_counter *this_cpu;
-	struct nft_counter total;
+	struct nft_counter_tot total;
 
 	nft_counter_fetch(priv, &total);
 
@@ -244,11 +248,9 @@ static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src, g
 	if (cpu_stats == NULL)
 		return -ENOMEM;
 
-	preempt_disable();
-	this_cpu = this_cpu_ptr(cpu_stats);
-	this_cpu->packets = total.packets;
-	this_cpu->bytes = total.bytes;
-	preempt_enable();
+	this_cpu = raw_cpu_ptr(cpu_stats);
+	u64_stats_set(&this_cpu->packets, total.packets);
+	u64_stats_set(&this_cpu->bytes, total.bytes);
 
 	priv_clone->counter = cpu_stats;
 	return 0;
@@ -266,17 +268,17 @@ static void nft_counter_offload_stats(struct nft_expr *expr,
 				      const struct flow_stats *stats)
 {
 	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
+	struct u64_stats_sync *nft_sync;
 	struct nft_counter *this_cpu;
-	seqcount_t *myseq;
 
 	local_bh_disable();
 	this_cpu = this_cpu_ptr(priv->counter);
-	myseq = this_cpu_ptr(&nft_counter_seq);
+	nft_sync = this_cpu_ptr(&nft_counter_sync);
 
-	write_seqcount_begin(myseq);
-	this_cpu->packets += stats->pkts;
-	this_cpu->bytes += stats->bytes;
-	write_seqcount_end(myseq);
+	u64_stats_update_begin(nft_sync);
+	u64_stats_add(&this_cpu->packets, stats->pkts);
+	u64_stats_add(&this_cpu->bytes, stats->bytes);
+	u64_stats_update_end(nft_sync);
 	local_bh_enable();
 }
 
@@ -308,7 +310,8 @@ static int __init nft_counter_module_init(void)
 	int cpu, err;
 
 	for_each_possible_cpu(cpu)
-		seqcount_init(per_cpu_ptr(&nft_counter_seq, cpu));
+		u64_stats_init(per_cpu_ptr(&nft_counter_sync, cpu));
+
 
 	err = nft_register_obj(&nft_counter_obj_type);
 	if (err < 0)
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index e6b9a7d4bd86b..74a48e7837cf2 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c
@@ -94,11 +94,11 @@ static unsigned int
 xt_rateest_tg(struct sk_buff *skb, const struct xt_action_param *par)
 {
 	const struct xt_rateest_target_info *info = par->targinfo;
-	struct gnet_stats_basic_packed *stats = &info->est->bstats;
+	struct gnet_stats_basic_sync *stats = &info->est->bstats;
 
 	spin_lock_bh(&info->est->lock);
-	stats->bytes += skb->len;
-	stats->packets++;
+	u64_stats_add(&stats->bytes, skb->len);
+	u64_stats_inc(&stats->packets);
 	spin_unlock_bh(&info->est->lock);
 
 	return XT_CONTINUE;
@@ -143,6 +143,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
 	if (!est)
 		goto err1;
 
+	gnet_stats_basic_sync_init(&est->bstats);
 	strlcpy(est->name, info->name, sizeof(est->name));
 	spin_lock_init(&est->lock);
 	est->refcnt		= 1;
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 20944a2e162e7..8d74477b4a3d0 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -481,16 +481,18 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 		atomic_set(&p->tcfa_bindcnt, 1);
 
 	if (cpustats) {
-		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
+		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
 		if (!p->cpu_bstats)
 			goto err1;
-		p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
+		p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
 		if (!p->cpu_bstats_hw)
 			goto err2;
 		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 		if (!p->cpu_qstats)
 			goto err3;
 	}
+	gnet_stats_basic_sync_init(&p->tcfa_bstats);
+	gnet_stats_basic_sync_init(&p->tcfa_bstats_hw);
 	spin_lock_init(&p->tcfa_lock);
 	p->tcfa_index = index;
 	p->tcfa_tm.install = jiffies;
@@ -500,7 +502,7 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 	if (est) {
 		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 					&p->tcfa_rate_est,
-					&p->tcfa_lock, NULL, est);
+					&p->tcfa_lock, false, est);
 		if (err)
 			goto err4;
 	}
@@ -1156,13 +1158,13 @@ void tcf_action_update_stats(struct tc_action *a, u64 bytes, u64 packets,
 			     u64 drops, bool hw)
 {
 	if (a->cpu_bstats) {
-		_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
+		_bstats_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
 
 		this_cpu_ptr(a->cpu_qstats)->drops += drops;
 
 		if (hw)
-			_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
-					   bytes, packets);
+			_bstats_update(this_cpu_ptr(a->cpu_bstats_hw),
+				       bytes, packets);
 		return;
 	}
 
@@ -1201,9 +1203,10 @@ int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 	if (err < 0)
 		goto errout;
 
-	if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
-	    gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
-				     &p->tcfa_bstats_hw) < 0 ||
+	if (gnet_stats_copy_basic(&d, p->cpu_bstats,
+				  &p->tcfa_bstats, false) < 0 ||
+	    gnet_stats_copy_basic_hw(&d, p->cpu_bstats_hw,
+				     &p->tcfa_bstats_hw, false) < 0 ||
 	    gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
 	    gnet_stats_copy_queue(&d, p->cpu_qstats,
 				  &p->tcfa_qstats,
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
index e3fa5b17ea7fc..27d4a3d556a6f 100644
--- a/net/sched/act_bpf.c
+++ b/net/sched/act_bpf.c
@@ -40,7 +40,7 @@ static int tcf_bpf_act(struct sk_buff *skb, const struct tc_action *act,
 	int action, filter_res;
 
 	tcf_lastuse_update(&prog->tcf_tm);
-	bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(prog->common.cpu_bstats), skb);
 
 	filter = rcu_dereference_bh(prog->filter);
 	if (at_ingress) {
diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
index 67f66d8756931..c0596ee0e333a 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -719,7 +719,7 @@ static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
 	u8 *tlv_data;
 	u16 metalen;
 
-	bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 	tcf_lastuse_update(&ife->tcf_tm);
 
 	if (skb_at_tc_ingress(skb))
@@ -807,7 +807,7 @@ static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
 			exceed_mtu = true;
 	}
 
-	bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 	tcf_lastuse_update(&ife->tcf_tm);
 
 	if (!metalen) {		/* no metadata to send */
diff --git a/net/sched/act_mpls.c b/net/sched/act_mpls.c
index 75a87a068c536..c05763f60bed0 100644
--- a/net/sched/act_mpls.c
+++ b/net/sched/act_mpls.c
@@ -58,7 +58,7 @@ static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a,
 	int ret, mac_len;
 
 	tcf_lastuse_update(&m->tcf_tm);
-	bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(m->common.cpu_bstats), skb);
 
 	/* Ensure 'data' points at mac_header prior calling mpls manipulating
 	 * functions.
diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index 498250c389a00..d555de9fc4bbd 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -124,7 +124,7 @@ static int tcf_police_init(struct net *net, struct nlattr *nla,
 					    police->common.cpu_bstats,
 					    &police->tcf_rate_est,
 					    &police->tcf_lock,
-					    NULL, est);
+					    false, est);
 		if (err)
 			goto failure;
 	} else if (tb[TCA_POLICE_AVRATE] &&
@@ -267,7 +267,7 @@ static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
 	int ret;
 
 	tcf_lastuse_update(&police->tcf_tm);
-	bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(police->common.cpu_bstats), skb);
 
 	ret = READ_ONCE(police->tcf_action);
 	p = rcu_dereference_bh(police->params);
diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index aa0b1215b58f4..eebb1710d3b2d 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -169,7 +169,7 @@ static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
 	int retval;
 
 	tcf_lastuse_update(&s->tcf_tm);
-	bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(s->common.cpu_bstats), skb);
 	retval = READ_ONCE(s->tcf_action);
 
 	psample_group = rcu_dereference_bh(s->psample_group);
diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index 2188554dac8d8..06efa08afff75 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -35,7 +35,8 @@ static int tcf_simp_act(struct sk_buff *skb, const struct tc_action *a,
 	 * then it would look like "hello_3" (without quotes)
 	 */
 	pr_info("simple: %s_%llu\n",
-	       (char *)d->tcfd_defdata, d->tcf_bstats.packets);
+		(char *)d->tcfd_defdata,
+		u64_stats_read(&d->tcf_bstats.packets));
 	spin_unlock(&d->tcf_lock);
 	return d->tcf_action;
 }
diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index 0c91f88476baf..9fe516dec118e 100644
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -30,7 +30,7 @@ static int tcf_skbedit_act(struct sk_buff *skb, const struct tc_action *a,
 	int action;
 
 	tcf_lastuse_update(&d->tcf_tm);
-	bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(d->common.cpu_bstats), skb);
 
 	params = rcu_dereference_bh(d->params);
 	action = READ_ONCE(d->tcf_action);
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
index 37395ab1df472..893ebd1ae70f9 100644
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -30,7 +30,7 @@ static int tcf_skbmod_act(struct sk_buff *skb, const struct tc_action *a,
 	u64 flags;
 
 	tcf_lastuse_update(&d->tcf_tm);
-	bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb);
+	bstats_update(this_cpu_ptr(d->common.cpu_bstats), skb);
 
 	action = READ_ONCE(d->tcf_action);
 	if (unlikely(action == TC_ACT_SHOT))
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index c9f7e793a375b..ab8ed591975cd 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -869,7 +869,7 @@ static void qdisc_offload_graft_root(struct net_device *dev,
 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 			 u32 portid, u32 seq, u16 flags, int event)
 {
-	struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
+	struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL;
 	struct gnet_stats_queue __percpu *cpu_qstats = NULL;
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
@@ -927,8 +927,7 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 		cpu_qstats = q->cpu_qstats;
 	}
 
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
-				  &d, cpu_bstats, &q->bstats) < 0 ||
+	if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 ||
 	    gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
 	    gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
 		goto nla_put_failure;
@@ -1266,26 +1265,17 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
 		rcu_assign_pointer(sch->stab, stab);
 	}
 	if (tca[TCA_RATE]) {
-		seqcount_t *running;
-
 		err = -EOPNOTSUPP;
 		if (sch->flags & TCQ_F_MQROOT) {
 			NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
 			goto err_out4;
 		}
 
-		if (sch->parent != TC_H_ROOT &&
-		    !(sch->flags & TCQ_F_INGRESS) &&
-		    (!p || !(p->flags & TCQ_F_MQROOT)))
-			running = qdisc_root_sleeping_running(sch);
-		else
-			running = &sch->running;
-
 		err = gen_new_estimator(&sch->bstats,
 					sch->cpu_bstats,
 					&sch->rate_est,
 					NULL,
-					running,
+					true,
 					tca[TCA_RATE]);
 		if (err) {
 			NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
@@ -1361,7 +1351,7 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
 				      sch->cpu_bstats,
 				      &sch->rate_est,
 				      NULL,
-				      qdisc_root_sleeping_running(sch),
+				      true,
 				      tca[TCA_RATE]);
 	}
 out:
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index a2b9802d41c01..da54678ecacc6 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -19,7 +19,7 @@ struct drr_class {
 	struct Qdisc_class_common	common;
 	unsigned int			filter_cnt;
 
-	struct gnet_stats_basic_packed		bstats;
+	struct gnet_stats_basic_sync		bstats;
 	struct gnet_stats_queue		qstats;
 	struct net_rate_estimator __rcu *rate_est;
 	struct list_head		alist;
@@ -90,8 +90,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 		if (tca[TCA_RATE]) {
 			err = gen_replace_estimator(&cl->bstats, NULL,
 						    &cl->rate_est,
-						    NULL,
-						    qdisc_root_sleeping_running(sch),
+						    NULL, true,
 						    tca[TCA_RATE]);
 			if (err) {
 				NL_SET_ERR_MSG(extack, "Failed to replace estimator");
@@ -111,6 +110,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	if (cl == NULL)
 		return -ENOBUFS;
 
+	gnet_stats_basic_sync_init(&cl->bstats);
 	INIT_LIST_HEAD(&cl->alist);
 	cl->common.classid = classid;
 	cl->quantum	   = quantum;
@@ -124,9 +124,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 
 	if (tca[TCA_RATE]) {
 		err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
-					    NULL,
-					    qdisc_root_sleeping_running(sch),
-					    tca[TCA_RATE]);
+					    NULL, true, tca[TCA_RATE]);
 		if (err) {
 			NL_SET_ERR_MSG(extack, "Failed to replace estimator");
 			qdisc_put(cl->qdisc);
@@ -273,8 +271,7 @@ static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 	if (qlen)
 		xstats.deficit = READ_ONCE(cl->deficit);
 
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
-				  d, NULL, &cl->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
 	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
 	    gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
 		return -1;
diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c
index 7691eb0e0ea4b..1c03f2aa1ffc1 100644
--- a/net/sched/sch_ets.c
+++ b/net/sched/sch_ets.c
@@ -41,7 +41,7 @@ struct ets_class {
 	struct Qdisc *qdisc;
 	u32 quantum;
 	u32 deficit;
-	struct gnet_stats_basic_packed bstats;
+	struct gnet_stats_basic_sync bstats;
 	struct gnet_stats_queue qstats;
 };
 
@@ -336,8 +336,7 @@ static int ets_class_dump_stats(struct Qdisc *sch, unsigned long arg,
 	struct ets_class *cl = ets_class_from_arg(sch, arg);
 	struct Qdisc *cl_q = cl->qdisc;
 
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
-				  d, NULL, &cl_q->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats, true) < 0 ||
 	    qdisc_qstats_copy(d, cl_q) < 0)
 		return -1;
 
@@ -703,9 +702,9 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
 	for (i = q->nbands; i < oldbands; i++) {
 		qdisc_put(q->classes[i].qdisc);
 		q->classes[i].qdisc = NULL;
-		WRITE_ONCE(q->classes[i].quantum, 0);
+		q->classes[i].quantum = 0;
 		q->classes[i].deficit = 0;
-		memset(&q->classes[i].bstats, 0, sizeof(q->classes[i].bstats));
+		gnet_stats_basic_sync_init(&q->classes[i].bstats);
 		memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats));
 	}
 	return 0;
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 565970cca295b..ead407b8890d4 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -307,8 +307,8 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate,
 
 /*
  * Transmit possibly several skbs, and handle the return status as
- * required. Owning running seqcount bit guarantees that
- * only one CPU can execute this function.
+ * required. Owning qdisc running bit guarantees that only one CPU
+ * can execute this function.
  *
  * Returns to the caller:
  *				false  - hardware queue frozen backoff
@@ -609,7 +609,6 @@ struct Qdisc noop_qdisc = {
 	.ops		=	&noop_qdisc_ops,
 	.q.lock		=	__SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
 	.dev_queue	=	&noop_netdev_queue,
-	.running	=	SEQCNT_ZERO(noop_qdisc.running),
 	.busylock	=	__SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
 	.gso_skb = {
 		.next = (struct sk_buff *)&noop_qdisc.gso_skb,
@@ -870,7 +869,6 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 EXPORT_SYMBOL(pfifo_fast_ops);
 
 static struct lock_class_key qdisc_tx_busylock;
-static struct lock_class_key qdisc_running_key;
 
 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 			  const struct Qdisc_ops *ops,
@@ -895,11 +893,12 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 	__skb_queue_head_init(&sch->gso_skb);
 	__skb_queue_head_init(&sch->skb_bad_txq);
 	qdisc_skb_head_init(&sch->q);
+	gnet_stats_basic_sync_init(&sch->bstats);
 	spin_lock_init(&sch->q.lock);
 
 	if (ops->static_flags & TCQ_F_CPUSTATS) {
 		sch->cpu_bstats =
-			netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
+			netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
 		if (!sch->cpu_bstats)
 			goto errout1;
 
@@ -919,10 +918,6 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 	lockdep_set_class(&sch->seqlock,
 			  dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
 
-	seqcount_init(&sch->running);
-	lockdep_set_class(&sch->running,
-			  dev->qdisc_running_key ?: &qdisc_running_key);
-
 	sch->ops = ops;
 	sch->flags = ops->static_flags;
 	sch->enqueue = ops->enqueue;
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 8caf9623f855f..e7af53f607bbd 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -56,6 +56,7 @@ struct gred_sched {
 	u32 		DPs;
 	u32 		def;
 	struct red_vars wred_set;
+	struct tc_gred_qopt_offload *opt;
 };
 
 static inline int gred_wred_mode(struct gred_sched *table)
@@ -311,48 +312,50 @@ static void gred_offload(struct Qdisc *sch, enum tc_gred_command command)
 {
 	struct gred_sched *table = qdisc_priv(sch);
 	struct net_device *dev = qdisc_dev(sch);
-	struct tc_gred_qopt_offload opt = {
-		.command	= command,
-		.handle		= sch->handle,
-		.parent		= sch->parent,
-	};
+	struct tc_gred_qopt_offload *opt = table->opt;
 
 	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 		return;
 
+	memset(opt, 0, sizeof(*opt));
+	opt->command = command;
+	opt->handle = sch->handle;
+	opt->parent = sch->parent;
+
 	if (command == TC_GRED_REPLACE) {
 		unsigned int i;
 
-		opt.set.grio_on = gred_rio_mode(table);
-		opt.set.wred_on = gred_wred_mode(table);
-		opt.set.dp_cnt = table->DPs;
-		opt.set.dp_def = table->def;
+		opt->set.grio_on = gred_rio_mode(table);
+		opt->set.wred_on = gred_wred_mode(table);
+		opt->set.dp_cnt = table->DPs;
+		opt->set.dp_def = table->def;
 
 		for (i = 0; i < table->DPs; i++) {
 			struct gred_sched_data *q = table->tab[i];
 
 			if (!q)
 				continue;
-			opt.set.tab[i].present = true;
-			opt.set.tab[i].limit = q->limit;
-			opt.set.tab[i].prio = q->prio;
-			opt.set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;
-			opt.set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;
-			opt.set.tab[i].is_ecn = gred_use_ecn(q);
-			opt.set.tab[i].is_harddrop = gred_use_harddrop(q);
-			opt.set.tab[i].probability = q->parms.max_P;
-			opt.set.tab[i].backlog = &q->backlog;
+			opt->set.tab[i].present = true;
+			opt->set.tab[i].limit = q->limit;
+			opt->set.tab[i].prio = q->prio;
+			opt->set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;
+			opt->set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;
+			opt->set.tab[i].is_ecn = gred_use_ecn(q);
+			opt->set.tab[i].is_harddrop = gred_use_harddrop(q);
+			opt->set.tab[i].probability = q->parms.max_P;
+			opt->set.tab[i].backlog = &q->backlog;
 		}
-		opt.set.qstats = &sch->qstats;
+		opt->set.qstats = &sch->qstats;
 	}
 
-	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, &opt);
+	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, opt);
 }
 
 static int gred_offload_dump_stats(struct Qdisc *sch)
 {
 	struct gred_sched *table = qdisc_priv(sch);
 	struct tc_gred_qopt_offload *hw_stats;
+	u64 bytes = 0, packets = 0;
 	unsigned int i;
 	int ret;
 
@@ -364,9 +367,11 @@ static int gred_offload_dump_stats(struct Qdisc *sch)
 	hw_stats->handle = sch->handle;
 	hw_stats->parent = sch->parent;
 
-	for (i = 0; i < MAX_DPs; i++)
+	for (i = 0; i < MAX_DPs; i++) {
+		gnet_stats_basic_sync_init(&hw_stats->stats.bstats[i]);
 		if (table->tab[i])
 			hw_stats->stats.xstats[i] = &table->tab[i]->stats;
+	}
 
 	ret = qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_GRED, hw_stats);
 	/* Even if driver returns failure adjust the stats - in case offload
@@ -375,19 +380,19 @@ static int gred_offload_dump_stats(struct Qdisc *sch)
 	for (i = 0; i < MAX_DPs; i++) {
 		if (!table->tab[i])
 			continue;
-		table->tab[i]->packetsin += hw_stats->stats.bstats[i].packets;
-		table->tab[i]->bytesin += hw_stats->stats.bstats[i].bytes;
+		table->tab[i]->packetsin += u64_stats_read(&hw_stats->stats.bstats[i].packets);
+		table->tab[i]->bytesin += u64_stats_read(&hw_stats->stats.bstats[i].bytes);
 		table->tab[i]->backlog += hw_stats->stats.qstats[i].backlog;
 
-		_bstats_update(&sch->bstats,
-			       hw_stats->stats.bstats[i].bytes,
-			       hw_stats->stats.bstats[i].packets);
+		bytes += u64_stats_read(&hw_stats->stats.bstats[i].bytes);
+		packets += u64_stats_read(&hw_stats->stats.bstats[i].packets);
 		sch->qstats.qlen += hw_stats->stats.qstats[i].qlen;
 		sch->qstats.backlog += hw_stats->stats.qstats[i].backlog;
 		sch->qstats.drops += hw_stats->stats.qstats[i].drops;
 		sch->qstats.requeues += hw_stats->stats.qstats[i].requeues;
 		sch->qstats.overlimits += hw_stats->stats.qstats[i].overlimits;
 	}
+	_bstats_update(&sch->bstats, bytes, packets);
 
 	kfree(hw_stats);
 	return ret;
@@ -728,6 +733,7 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt,
 static int gred_init(struct Qdisc *sch, struct nlattr *opt,
 		     struct netlink_ext_ack *extack)
 {
+	struct gred_sched *table = qdisc_priv(sch);
 	struct nlattr *tb[TCA_GRED_MAX + 1];
 	int err;
 
@@ -751,6 +757,12 @@ static int gred_init(struct Qdisc *sch, struct nlattr *opt,
 		sch->limit = qdisc_dev(sch)->tx_queue_len
 		             * psched_mtu(qdisc_dev(sch));
 
+	if (qdisc_dev(sch)->netdev_ops->ndo_setup_tc) {
+		table->opt = kzalloc(sizeof(*table->opt), GFP_KERNEL);
+		if (!table->opt)
+			return -ENOMEM;
+	}
+
 	return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
 }
 
@@ -904,6 +916,7 @@ static void gred_destroy(struct Qdisc *sch)
 			gred_destroy_vq(table->tab[i]);
 	}
 	gred_offload(sch, TC_GRED_DESTROY);
+	kfree(table->opt);
 }
 
 static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 35a439a6d9a28..ff4bfe4d2273f 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -111,7 +111,7 @@ enum hfsc_class_flags {
 struct hfsc_class {
 	struct Qdisc_class_common cl_common;
 
-	struct gnet_stats_basic_packed bstats;
+	struct gnet_stats_basic_sync bstats;
 	struct gnet_stats_queue qstats;
 	struct net_rate_estimator __rcu *rate_est;
 	struct tcf_proto __rcu *filter_list; /* filter list */
@@ -966,7 +966,7 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 			err = gen_replace_estimator(&cl->bstats, NULL,
 						    &cl->rate_est,
 						    NULL,
-						    qdisc_root_sleeping_running(sch),
+						    true,
 						    tca[TCA_RATE]);
 			if (err)
 				return err;
@@ -1040,9 +1040,7 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 
 	if (tca[TCA_RATE]) {
 		err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
-					NULL,
-					qdisc_root_sleeping_running(sch),
-					tca[TCA_RATE]);
+					NULL, true, tca[TCA_RATE]);
 		if (err) {
 			tcf_block_put(cl->block);
 			kfree(cl);
@@ -1342,7 +1340,7 @@ hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 	xstats.work    = READ_ONCE(cl->cl_total);
 	xstats.rtwork  = READ_ONCE(cl->cl_cumul);
 
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d, NULL, &cl->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
 	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
 	    gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
 		return -1;
@@ -1420,6 +1418,7 @@ hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
 	if (err)
 		return err;
 
+	gnet_stats_basic_sync_init(&q->root.bstats);
 	q->root.cl_common.classid = sch->handle;
 	q->root.sched   = q;
 	q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 2c73f49740dee..827cf98134deb 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -113,8 +113,8 @@ struct htb_class {
 	/*
 	 * Written often fields
 	 */
-	struct gnet_stats_basic_packed bstats;
-	struct gnet_stats_basic_packed bstats_bias;
+	struct gnet_stats_basic_sync bstats;
+	struct gnet_stats_basic_sync bstats_bias;
 	struct tc_htb_xstats	xstats;	/* our special stats */
 
 	/* token bucket parameters */
@@ -1308,10 +1308,11 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
 static void htb_offload_aggregate_stats(struct htb_sched *q,
 					struct htb_class *cl)
 {
+	u64 bytes = 0, packets = 0;
 	struct htb_class *c;
 	unsigned int i;
 
-	memset(&cl->bstats, 0, sizeof(cl->bstats));
+	gnet_stats_basic_sync_init(&cl->bstats);
 
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(c, &q->clhash.hash[i], common.hnode) {
@@ -1323,14 +1324,15 @@ static void htb_offload_aggregate_stats(struct htb_sched *q,
 			if (p != cl)
 				continue;
 
-			cl->bstats.bytes += c->bstats_bias.bytes;
-			cl->bstats.packets += c->bstats_bias.packets;
+			bytes += u64_stats_read(&c->bstats_bias.bytes);
+			packets += u64_stats_read(&c->bstats_bias.packets);
 			if (c->level == 0) {
-				cl->bstats.bytes += c->leaf.q->bstats.bytes;
-				cl->bstats.packets += c->leaf.q->bstats.packets;
+				bytes += u64_stats_read(&c->leaf.q->bstats.bytes);
+				packets += u64_stats_read(&c->leaf.q->bstats.packets);
 			}
 		}
 	}
+	_bstats_update(&cl->bstats, bytes, packets);
 }
 
 static int
@@ -1357,16 +1359,16 @@ htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
 			if (cl->leaf.q)
 				cl->bstats = cl->leaf.q->bstats;
 			else
-				memset(&cl->bstats, 0, sizeof(cl->bstats));
-			cl->bstats.bytes += cl->bstats_bias.bytes;
-			cl->bstats.packets += cl->bstats_bias.packets;
+				gnet_stats_basic_sync_init(&cl->bstats);
+			_bstats_update(&cl->bstats,
+				       u64_stats_read(&cl->bstats_bias.bytes),
+				       u64_stats_read(&cl->bstats_bias.packets));
 		} else {
 			htb_offload_aggregate_stats(q, cl);
 		}
 	}
 
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
-				  d, NULL, &cl->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
 	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
 	    gnet_stats_copy_queue(d, NULL, &qs, qlen) < 0)
 		return -1;
@@ -1581,8 +1583,9 @@ static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl,
 	}
 
 	if (cl->parent) {
-		cl->parent->bstats_bias.bytes += q->bstats.bytes;
-		cl->parent->bstats_bias.packets += q->bstats.packets;
+		_bstats_update(&cl->parent->bstats_bias,
+			       u64_stats_read(&q->bstats.bytes),
+			       u64_stats_read(&q->bstats.packets));
 	}
 
 	offload_opt = (struct tc_htb_qopt_offload) {
@@ -1873,6 +1876,9 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 		if (!cl)
 			goto failure;
 
+		gnet_stats_basic_sync_init(&cl->bstats);
+		gnet_stats_basic_sync_init(&cl->bstats_bias);
+
 		err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
 		if (err) {
 			kfree(cl);
@@ -1882,7 +1888,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 			err = gen_new_estimator(&cl->bstats, NULL,
 						&cl->rate_est,
 						NULL,
-						qdisc_root_sleeping_running(sch),
+						true,
 						tca[TCA_RATE] ? : &est.nla);
 			if (err)
 				goto err_block_put;
@@ -1946,8 +1952,9 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 				htb_graft_helper(dev_queue, old_q);
 				goto err_kill_estimator;
 			}
-			parent->bstats_bias.bytes += old_q->bstats.bytes;
-			parent->bstats_bias.packets += old_q->bstats.packets;
+			_bstats_update(&parent->bstats_bias,
+				       u64_stats_read(&old_q->bstats.bytes),
+				       u64_stats_read(&old_q->bstats.packets));
 			qdisc_put(old_q);
 		}
 		new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
@@ -2006,7 +2013,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 			err = gen_replace_estimator(&cl->bstats, NULL,
 						    &cl->rate_est,
 						    NULL,
-						    qdisc_root_sleeping_running(sch),
+						    true,
 						    tca[TCA_RATE]);
 			if (err)
 				return err;
diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index db18d8a860f9c..24c5d97d88ddf 100644
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -153,10 +153,9 @@ static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
 	struct net_device *dev = qdisc_dev(sch);
 	struct Qdisc *qdisc;
 	unsigned int ntx;
-	__u32 qlen = 0;
 
 	sch->q.qlen = 0;
-	memset(&sch->bstats, 0, sizeof(sch->bstats));
+	gnet_stats_basic_sync_init(&sch->bstats);
 	memset(&sch->qstats, 0, sizeof(sch->qstats));
 
 	/* MQ supports lockless qdiscs. However, statistics accounting needs
@@ -168,25 +167,11 @@ static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
 		qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
 		spin_lock_bh(qdisc_lock(qdisc));
 
-		if (qdisc_is_percpu_stats(qdisc)) {
-			qlen = qdisc_qlen_sum(qdisc);
-			__gnet_stats_copy_basic(NULL, &sch->bstats,
-						qdisc->cpu_bstats,
-						&qdisc->bstats);
-			__gnet_stats_copy_queue(&sch->qstats,
-						qdisc->cpu_qstats,
-						&qdisc->qstats, qlen);
-			sch->q.qlen		+= qlen;
-		} else {
-			sch->q.qlen		+= qdisc->q.qlen;
-			sch->bstats.bytes	+= qdisc->bstats.bytes;
-			sch->bstats.packets	+= qdisc->bstats.packets;
-			sch->qstats.qlen	+= qdisc->qstats.qlen;
-			sch->qstats.backlog	+= qdisc->qstats.backlog;
-			sch->qstats.drops	+= qdisc->qstats.drops;
-			sch->qstats.requeues	+= qdisc->qstats.requeues;
-			sch->qstats.overlimits	+= qdisc->qstats.overlimits;
-		}
+		gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats,
+				     &qdisc->bstats, false);
+		gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats,
+				     &qdisc->qstats);
+		sch->q.qlen += qdisc_qlen(qdisc);
 
 		spin_unlock_bh(qdisc_lock(qdisc));
 	}
@@ -269,8 +254,7 @@ static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 	struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
 
 	sch = dev_queue->qdisc_sleeping;
-	if (gnet_stats_copy_basic(&sch->running, d, sch->cpu_bstats,
-				  &sch->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, sch->cpu_bstats, &sch->bstats, true) < 0 ||
 	    qdisc_qstats_copy(d, sch) < 0)
 		return -1;
 	return 0;
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 56d3dc5e95c7c..b7ca9c7d83b4c 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -454,7 +454,7 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 	unsigned int ntx, tc;
 
 	sch->q.qlen = 0;
-	memset(&sch->bstats, 0, sizeof(sch->bstats));
+	gnet_stats_basic_sync_init(&sch->bstats);
 	memset(&sch->qstats, 0, sizeof(sch->qstats));
 
 	/* MQ supports lockless qdiscs. However, statistics accounting needs
@@ -466,25 +466,11 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 		qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
 		spin_lock_bh(qdisc_lock(qdisc));
 
-		if (qdisc_is_percpu_stats(qdisc)) {
-			__u32 qlen = qdisc_qlen_sum(qdisc);
-
-			__gnet_stats_copy_basic(NULL, &sch->bstats,
-						qdisc->cpu_bstats,
-						&qdisc->bstats);
-			__gnet_stats_copy_queue(&sch->qstats,
-						qdisc->cpu_qstats,
-						&qdisc->qstats, qlen);
-			sch->q.qlen		+= qlen;
-		} else {
-			sch->q.qlen		+= qdisc->q.qlen;
-			sch->bstats.bytes	+= qdisc->bstats.bytes;
-			sch->bstats.packets	+= qdisc->bstats.packets;
-			sch->qstats.backlog	+= qdisc->qstats.backlog;
-			sch->qstats.drops	+= qdisc->qstats.drops;
-			sch->qstats.requeues	+= qdisc->qstats.requeues;
-			sch->qstats.overlimits	+= qdisc->qstats.overlimits;
-		}
+		gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats,
+				     &qdisc->bstats, false);
+		gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats,
+				     &qdisc->qstats);
+		sch->q.qlen += qdisc_qlen(qdisc);
 
 		spin_unlock_bh(qdisc_lock(qdisc));
 	}
@@ -576,12 +562,13 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 {
 	if (cl >= TC_H_MIN_PRIORITY) {
 		int i;
-		__u32 qlen = 0;
+		__u32 qlen;
 		struct gnet_stats_queue qstats = {0};
-		struct gnet_stats_basic_packed bstats = {0};
+		struct gnet_stats_basic_sync bstats;
 		struct net_device *dev = qdisc_dev(sch);
 		struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
 
+		gnet_stats_basic_sync_init(&bstats);
 		/* Drop lock here it will be reclaimed before touching
 		 * statistics this is required because the d->lock we
 		 * hold here is the look on dev_queue->qdisc_sleeping
@@ -596,40 +583,28 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 
 			spin_lock_bh(qdisc_lock(qdisc));
 
-			if (qdisc_is_percpu_stats(qdisc)) {
-				qlen = qdisc_qlen_sum(qdisc);
-
-				__gnet_stats_copy_basic(NULL, &bstats,
-							qdisc->cpu_bstats,
-							&qdisc->bstats);
-				__gnet_stats_copy_queue(&qstats,
-							qdisc->cpu_qstats,
-							&qdisc->qstats,
-							qlen);
-			} else {
-				qlen		+= qdisc->q.qlen;
-				bstats.bytes	+= qdisc->bstats.bytes;
-				bstats.packets	+= qdisc->bstats.packets;
-				qstats.backlog	+= qdisc->qstats.backlog;
-				qstats.drops	+= qdisc->qstats.drops;
-				qstats.requeues	+= qdisc->qstats.requeues;
-				qstats.overlimits += qdisc->qstats.overlimits;
-			}
+			gnet_stats_add_basic(&bstats, qdisc->cpu_bstats,
+					     &qdisc->bstats, false);
+			gnet_stats_add_queue(&qstats, qdisc->cpu_qstats,
+					     &qdisc->qstats);
+			sch->q.qlen += qdisc_qlen(qdisc);
+
 			spin_unlock_bh(qdisc_lock(qdisc));
 		}
+		qlen = qdisc_qlen(sch) + qstats.qlen;
 
 		/* Reclaim root sleeping lock before completing stats */
 		if (d->lock)
 			spin_lock_bh(d->lock);
-		if (gnet_stats_copy_basic(NULL, d, NULL, &bstats) < 0 ||
+		if (gnet_stats_copy_basic(d, NULL, &bstats, false) < 0 ||
 		    gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
 			return -1;
 	} else {
 		struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 
 		sch = dev_queue->qdisc_sleeping;
-		if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d,
-					  sch->cpu_bstats, &sch->bstats) < 0 ||
+		if (gnet_stats_copy_basic(d, sch->cpu_bstats,
+					  &sch->bstats, true) < 0 ||
 		    qdisc_qstats_copy(d, sch) < 0)
 			return -1;
 	}
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 417e231d22eb6..a5d692145d815 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -337,8 +337,7 @@ static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 	struct Qdisc *cl_q;
 
 	cl_q = q->queues[cl - 1];
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
-				  d, cl_q->cpu_bstats, &cl_q->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, cl_q->cpu_bstats, &cl_q->bstats, true) < 0 ||
 	    qdisc_qstats_copy(d, cl_q) < 0)
 		return -1;
 
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index b3defe09d9f7b..1b17be2dd35e0 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -359,8 +359,8 @@ static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 	struct Qdisc *cl_q;
 
 	cl_q = q->queues[cl - 1];
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
-				  d, cl_q->cpu_bstats, &cl_q->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, cl_q->cpu_bstats,
+				  &cl_q->bstats, true) < 0 ||
 	    qdisc_qstats_copy(d, cl_q) < 0)
 		return -1;
 
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index 8e5b30c447b86..2a3684e885395 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -132,7 +132,7 @@ struct qfq_class {
 
 	unsigned int filter_cnt;
 
-	struct gnet_stats_basic_packed bstats;
+	struct gnet_stats_basic_sync bstats;
 	struct gnet_stats_queue qstats;
 	struct net_rate_estimator __rcu *rate_est;
 	struct Qdisc *qdisc;
@@ -470,7 +470,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 			err = gen_replace_estimator(&cl->bstats, NULL,
 						    &cl->rate_est,
 						    NULL,
-						    qdisc_root_sleeping_running(sch),
+						    true,
 						    tca[TCA_RATE]);
 			if (err)
 				return err;
@@ -484,6 +484,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	if (cl == NULL)
 		return -ENOBUFS;
 
+	gnet_stats_basic_sync_init(&cl->bstats);
 	cl->common.classid = classid;
 	cl->deficit = lmax;
 	INIT_LIST_HEAD(&cl->alist);
@@ -497,7 +498,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 		err = gen_new_estimator(&cl->bstats, NULL,
 					&cl->rate_est,
 					NULL,
-					qdisc_root_sleeping_running(sch),
+					true,
 					tca[TCA_RATE]);
 		if (err)
 			goto destroy_class;
@@ -667,8 +668,7 @@ static int qfq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 	xstats.lmax = cl->agg->lmax;
 	sch_tree_unlock(sch);
 
-	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
-				  d, NULL, &cl->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
 	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
 	    qdisc_qstats_copy(d, cl->qdisc) < 0)
 		return -1;
@@ -1272,8 +1272,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		return err;
 	}
 
-	cl->bstats.bytes += len;
-	cl->bstats.packets += gso_segs;
+	_bstats_update(&cl->bstats, len, gso_segs);
 	sch->qstats.backlog += len;
 	++sch->q.qlen;
 
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 8e7c0a3034cc4..3b50feba21bce 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1964,7 +1964,7 @@ static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 	struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
 
 	sch = dev_queue->qdisc_sleeping;
-	if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
+	if (gnet_stats_copy_basic(d, NULL, &sch->bstats, true) < 0 ||
 	    qdisc_qstats_copy(d, sch) < 0)
 		return -1;
 	return 0;
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 3cf53e3140a5a..af9e6d531f007 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -462,7 +462,7 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
 	if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
 		return;
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
 
 	atomic_long_inc(&pool->sp_stats.packets);
@@ -486,7 +486,7 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
 	rqstp = NULL;
 out_unlock:
 	rcu_read_unlock();
-	put_cpu();
+	put_cpu_light();
 	trace_svc_xprt_do_enqueue(xprt, rqstp);
 }
 EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
diff --git a/samples/kfifo/bytestream-example.c b/samples/kfifo/bytestream-example.c
index 5a90aa5278775..642d0748c1695 100644
--- a/samples/kfifo/bytestream-example.c
+++ b/samples/kfifo/bytestream-example.c
@@ -22,10 +22,10 @@
 #define	PROC_FIFO	"bytestream-fifo"
 
 /* lock for procfs read access */
-static DEFINE_MUTEX(read_lock);
+static DEFINE_MUTEX(read_access);
 
 /* lock for procfs write access */
-static DEFINE_MUTEX(write_lock);
+static DEFINE_MUTEX(write_access);
 
 /*
  * define DYNAMIC in this example for a dynamically allocated fifo.
@@ -116,12 +116,12 @@ static ssize_t fifo_write(struct file *file, const char __user *buf,
 	int ret;
 	unsigned int copied;
 
-	if (mutex_lock_interruptible(&write_lock))
+	if (mutex_lock_interruptible(&write_access))
 		return -ERESTARTSYS;
 
 	ret = kfifo_from_user(&test, buf, count, &copied);
 
-	mutex_unlock(&write_lock);
+	mutex_unlock(&write_access);
 	if (ret)
 		return ret;
 
@@ -134,12 +134,12 @@ static ssize_t fifo_read(struct file *file, char __user *buf,
 	int ret;
 	unsigned int copied;
 
-	if (mutex_lock_interruptible(&read_lock))
+	if (mutex_lock_interruptible(&read_access))
 		return -ERESTARTSYS;
 
 	ret = kfifo_to_user(&test, buf, count, &copied);
 
-	mutex_unlock(&read_lock);
+	mutex_unlock(&read_access);
 	if (ret)
 		return ret;
 
diff --git a/samples/kfifo/inttype-example.c b/samples/kfifo/inttype-example.c
index e5403d8c971a5..c61482ba94f4d 100644
--- a/samples/kfifo/inttype-example.c
+++ b/samples/kfifo/inttype-example.c
@@ -22,10 +22,10 @@
 #define	PROC_FIFO	"int-fifo"
 
 /* lock for procfs read access */
-static DEFINE_MUTEX(read_lock);
+static DEFINE_MUTEX(read_access);
 
 /* lock for procfs write access */
-static DEFINE_MUTEX(write_lock);
+static DEFINE_MUTEX(write_access);
 
 /*
  * define DYNAMIC in this example for a dynamically allocated fifo.
@@ -109,12 +109,12 @@ static ssize_t fifo_write(struct file *file, const char __user *buf,
 	int ret;
 	unsigned int copied;
 
-	if (mutex_lock_interruptible(&write_lock))
+	if (mutex_lock_interruptible(&write_access))
 		return -ERESTARTSYS;
 
 	ret = kfifo_from_user(&test, buf, count, &copied);
 
-	mutex_unlock(&write_lock);
+	mutex_unlock(&write_access);
 	if (ret)
 		return ret;
 
@@ -127,12 +127,12 @@ static ssize_t fifo_read(struct file *file, char __user *buf,
 	int ret;
 	unsigned int copied;
 
-	if (mutex_lock_interruptible(&read_lock))
+	if (mutex_lock_interruptible(&read_access))
 		return -ERESTARTSYS;
 
 	ret = kfifo_to_user(&test, buf, count, &copied);
 
-	mutex_unlock(&read_lock);
+	mutex_unlock(&read_access);
 	if (ret)
 		return ret;
 
diff --git a/samples/kfifo/record-example.c b/samples/kfifo/record-example.c
index f64f3d62d6c2a..e4087b2d3fc4b 100644
--- a/samples/kfifo/record-example.c
+++ b/samples/kfifo/record-example.c
@@ -22,10 +22,10 @@
 #define	PROC_FIFO	"record-fifo"
 
 /* lock for procfs read access */
-static DEFINE_MUTEX(read_lock);
+static DEFINE_MUTEX(read_access);
 
 /* lock for procfs write access */
-static DEFINE_MUTEX(write_lock);
+static DEFINE_MUTEX(write_access);
 
 /*
  * define DYNAMIC in this example for a dynamically allocated fifo.
@@ -123,12 +123,12 @@ static ssize_t fifo_write(struct file *file, const char __user *buf,
 	int ret;
 	unsigned int copied;
 
-	if (mutex_lock_interruptible(&write_lock))
+	if (mutex_lock_interruptible(&write_access))
 		return -ERESTARTSYS;
 
 	ret = kfifo_from_user(&test, buf, count, &copied);
 
-	mutex_unlock(&write_lock);
+	mutex_unlock(&write_access);
 	if (ret)
 		return ret;
 
@@ -141,12 +141,12 @@ static ssize_t fifo_read(struct file *file, char __user *buf,
 	int ret;
 	unsigned int copied;
 
-	if (mutex_lock_interruptible(&read_lock))
+	if (mutex_lock_interruptible(&read_access))
 		return -ERESTARTSYS;
 
 	ret = kfifo_to_user(&test, buf, count, &copied);
 
-	mutex_unlock(&read_lock);
+	mutex_unlock(&read_access);
 	if (ret)
 		return ret;
 
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 6075c43999675..85adfaedfb93d 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -51,8 +51,10 @@
 #define SMK_RECEIVING	1
 #define SMK_SENDING	2
 
+#ifdef SMACK_IPV6_PORT_LABELING
 static DEFINE_MUTEX(smack_ipv6_lock);
 static LIST_HEAD(smk_ipv6_port_list);
+#endif
 struct kmem_cache *smack_rule_cache;
 int smack_enabled __initdata;
 
@@ -2633,7 +2635,6 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
 	mutex_unlock(&smack_ipv6_lock);
 	return;
 }
-#endif
 
 /**
  * smk_ipv6_port_check - check Smack port access
@@ -2696,6 +2697,7 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
 
 	return smk_ipv6_check(skp, object, address, act);
 }
+#endif
 
 /**
  * smack_inode_setsecurity - set smack xattrs
@@ -2891,8 +2893,9 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
 			rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
 					    SMK_CONNECTING);
 		}
-		if (__is_defined(SMACK_IPV6_PORT_LABELING))
-			rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
+#ifdef SMACK_IPV6_PORT_LABELING
+		rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
+#endif
 
 		return rc;
 	}
diff --git a/sound/soc/mediatek/common/mtk-afe-fe-dai.c b/sound/soc/mediatek/common/mtk-afe-fe-dai.c
index e95c7c018e7d4..4f2c2379531b9 100644
--- a/sound/soc/mediatek/common/mtk-afe-fe-dai.c
+++ b/sound/soc/mediatek/common/mtk-afe-fe-dai.c
@@ -288,7 +288,6 @@ const struct snd_soc_dai_ops mtk_afe_fe_ops = {
 };
 EXPORT_SYMBOL_GPL(mtk_afe_fe_ops);
 
-static DEFINE_MUTEX(irqs_lock);
 int mtk_dynamic_irq_acquire(struct mtk_base_afe *afe)
 {
 	int i;
