Merge tag 'v3.14.44-rt44-lno1' of git://git.linaro.org/people/anders.roxell/linux-rt into linux-linaro-lsk-v3.14-rt

Linux 3.14.44-rt44

Changes since v3.14.43-rt42:
- irq_work: Split raised and lazy lists
- irq_work: Introduce arch_irq_work_has_interrupt()

* tag 'v3.14.44-rt44-lno1' of git://git.linaro.org/people/anders.roxell/linux-rt: (360 commits)
  Linux 3.14.44-rt44 REBASE
  irq_work: Split raised and lazy lists
  irq_work: Introduce arch_irq_work_has_interrupt()
  rt, nohz_full: fix nohz_full for PREEMPT_RT_FULL
  hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread()
  KVM: use simple waitqueue for vcpu->wq
  KVM: lapic: mark LAPIC timer handler as irqsafe
  kernel/irq_work: fix no_hz deadlock
  netpoll: guard the access to dev->npinfo with rcu_read_lock/unlock_bh() for CONFIG_PREEMPT_RT_FULL=y
  Revert "timers: do not raise softirq unconditionally"
  fs,btrfs: fix rt deadlock on extent_buffer->lock
  staging: Mark rtl8821ae as broken
  timers: Reduce future __run_timers() latency for first add to empty list
  timers: Reduce future __run_timers() latency for newly emptied list
  timers: Reduce __run_timers() latency for empty list
  timers: Track total number of timers in list
  fs/aio: simple simple work
  lockdep: selftest: fix warnings due to missing PREEMPT_RT conditionals
  thermal: Defer thermal wakups to threads
  locking: ww_mutex: fix ww_mutex vs self-deadlock
  ...

34 files changed, 82 insertions, 47 deletions

diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild
index a73a8e208a4a..aca4359ceeb2 100644
--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -5,3 +5,4 @@ generic-y += exec.h
 generic-y += trace_clock.h
 generic-y += preempt.h
 generic-y += hash.h
+generic-y += irq_work.h
diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild
index 0d3362991c31..1c828e49a120 100644
--- a/arch/arc/include/asm/Kbuild
+++ b/arch/arc/include/asm/Kbuild
@@ -18,6 +18,7 @@ generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kmap_types.h
 generic-y += kvm_para.h
 generic-y += local.h
diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
index 3278afe2c3ab..0657adccbd90 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -10,6 +10,7 @@ generic-y += exec.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += local.h
 generic-y += local64.h
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index bd36b3013f82..55f6c27f341d 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -18,6 +18,7 @@ generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += kvm_para.h
diff --git a/arch/avr32/include/asm/Kbuild b/arch/avr32/include/asm/Kbuild
index c7c64a63c29f..83b594e48b3b 100644
--- a/arch/avr32/include/asm/Kbuild
+++ b/arch/avr32/include/asm/Kbuild
@@ -9,6 +9,7 @@ generic-y	+= exec.h
 generic-y       += futex.h
 generic-y	+= preempt.h
 generic-y       += irq_regs.h
+generic-y	+= irq_work.h
 generic-y	+= param.h
 generic-y       += local.h
 generic-y       += local64.h
diff --git a/arch/blackfin/include/asm/Kbuild b/arch/blackfin/include/asm/Kbuild
index 359d36fdc247..c80efff67f25 100644
--- a/arch/blackfin/include/asm/Kbuild
+++ b/arch/blackfin/include/asm/Kbuild
@@ -14,6 +14,7 @@ generic-y += hw_irq.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += kvm_para.h
diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild
index d73bb85ccdd3..22504509de7c 100644
--- a/arch/c6x/include/asm/Kbuild
+++ b/arch/c6x/include/asm/Kbuild
@@ -21,6 +21,7 @@ generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += local.h
diff --git a/arch/cris/include/asm/Kbuild b/arch/cris/include/asm/Kbuild
index f3fd8768f095..05c068a465f8 100644
--- a/arch/cris/include/asm/Kbuild
+++ b/arch/cris/include/asm/Kbuild
@@ -14,3 +14,4 @@ generic-y += trace_clock.h
 generic-y += vga.h
 generic-y += xor.h
 generic-y += preempt.h
+generic-y += irq_work.h
diff --git a/arch/frv/include/asm/Kbuild b/arch/frv/include/asm/Kbuild
index bc42f14c9c2e..9467583a22d1 100644
--- a/arch/frv/include/asm/Kbuild
+++ b/arch/frv/include/asm/Kbuild
@@ -4,3 +4,4 @@ generic-y += exec.h
 generic-y += trace_clock.h
 generic-y += preempt.h
 generic-y += hash.h
+generic-y += irq_work.h
diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild
index 38ca45d3df1e..42490ec70db9 100644
--- a/arch/hexagon/include/asm/Kbuild
+++ b/arch/hexagon/include/asm/Kbuild
@@ -23,6 +23,7 @@ generic-y += ioctls.h
 generic-y += iomap.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += local64.h
diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild
index 283a83154b5e..0007e559fb26 100644
--- a/arch/ia64/include/asm/Kbuild
+++ b/arch/ia64/include/asm/Kbuild
@@ -3,6 +3,7 @@ generic-y += clkdev.h
 generic-y += exec.h
 generic-y += kvm_para.h
 generic-y += trace_clock.h
+generic-y += irq_work.h
 generic-y += preempt.h
 generic-y += vtime.h
 generic-y += hash.h
diff --git a/arch/m32r/include/asm/Kbuild b/arch/m32r/include/asm/Kbuild
index 932435ac4e5c..afd0830e2937 100644
--- a/arch/m32r/include/asm/Kbuild
+++ b/arch/m32r/include/asm/Kbuild
@@ -5,3 +5,4 @@ generic-y += module.h
 generic-y += trace_clock.h
 generic-y += preempt.h
 generic-y += hash.h
+generic-y += irq_work.h
diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild
index 6fb9e813a910..bb51ed159f15 100644
--- a/arch/m68k/include/asm/Kbuild
+++ b/arch/m68k/include/asm/Kbuild
@@ -11,6 +11,7 @@ generic-y += hw_irq.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += kvm_para.h
diff --git a/arch/metag/include/asm/Kbuild b/arch/metag/include/asm/Kbuild
index b716d807c2ec..d64c4a68dd66 100644
--- a/arch/metag/include/asm/Kbuild
+++ b/arch/metag/include/asm/Kbuild
@@ -18,6 +18,7 @@ generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += kvm_para.h
diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild
index 2b98bc73642a..b8263e5430b3 100644
--- a/arch/microblaze/include/asm/Kbuild
+++ b/arch/microblaze/include/asm/Kbuild
@@ -3,6 +3,7 @@ generic-y += barrier.h
 generic-y += clkdev.h
 generic-y += exec.h
 generic-y += hash.h
+generic-y += irq_work.h
 generic-y += trace_clock.h
 generic-y += syscalls.h
 generic-y += preempt.h
diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild
index 2d7f65052c1f..e15b31a55f4b 100644
--- a/arch/mips/include/asm/Kbuild
+++ b/arch/mips/include/asm/Kbuild
@@ -15,3 +15,4 @@ generic-y += preempt.h
 generic-y += ucontext.h
 generic-y += xor.h
 generic-y += hash.h
+generic-y += irq_work.h
diff --git a/arch/mn10300/include/asm/Kbuild b/arch/mn10300/include/asm/Kbuild
index 992e989ab785..76459a99d77c 100644
--- a/arch/mn10300/include/asm/Kbuild
+++ b/arch/mn10300/include/asm/Kbuild
@@ -5,3 +5,4 @@ generic-y += exec.h
 generic-y += hash.h
 generic-y += trace_clock.h
 generic-y += preempt.h
+generic-y += irq_work.h
diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild
index 2e40f1ca8667..3bafc67f974e 100644
--- a/arch/openrisc/include/asm/Kbuild
+++ b/arch/openrisc/include/asm/Kbuild
@@ -30,6 +30,7 @@ generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += kvm_para.h
diff --git a/arch/parisc/include/asm/Kbuild b/arch/parisc/include/asm/Kbuild
index 752c981bc3c7..aa1a01ebef44 100644
--- a/arch/parisc/include/asm/Kbuild
+++ b/arch/parisc/include/asm/Kbuild
@@ -4,6 +4,7 @@ generic-y += word-at-a-time.h auxvec.h user.h cputime.h emergency-restart.h \
 	  segment.h topology.h vga.h device.h percpu.h hw_irq.h mutex.h \
 	  div64.h irq_regs.h kdebug.h kvm_para.h local64.h local.h param.h \
 	  poll.h xor.h clkdev.h exec.h
+generic-y += irq_work.h
 generic-y += trace_clock.h
 generic-y += preempt.h
 generic-y += hash.h
diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
index 6c0a955a1b06..80444f451d14 100644
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -5,3 +5,4 @@ generic-y += trace_clock.h
 generic-y += preempt.h
 generic-y += vtime.h
 generic-y += hash.h
+generic-y += irq_work.h
diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild
index 8386a4a1f19a..7cb4ef10a768 100644
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -4,3 +4,4 @@ generic-y += clkdev.h
 generic-y += trace_clock.h
 generic-y += preempt.h
 generic-y += hash.h
+generic-y += irq_work.h
diff --git a/arch/score/include/asm/Kbuild b/arch/score/include/asm/Kbuild
index 146b9d5e89f8..9c630eadb3ad 100644
--- a/arch/score/include/asm/Kbuild
+++ b/arch/score/include/asm/Kbuild
@@ -7,4 +7,5 @@ generic-y += hash.h
 generic-y += trace_clock.h
 generic-y += xor.h
 generic-y += preempt.h
+generic-y += irq_work.h
 
diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild
index 0cd7198a4524..60037fdcb1da 100644
--- a/arch/sh/include/asm/Kbuild
+++ b/arch/sh/include/asm/Kbuild
@@ -11,6 +11,7 @@ generic-y += fcntl.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kvm_para.h
 generic-y += local.h
 generic-y += local64.h
diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild
index 4b60a0c325ec..abf1a733fd77 100644
--- a/arch/sparc/include/asm/Kbuild
+++ b/arch/sparc/include/asm/Kbuild
@@ -10,6 +10,7 @@ generic-y += linkage.h
 generic-y += local64.h
 generic-y += mutex.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += local.h
 generic-y += module.h
 generic-y += serial.h
diff --git a/arch/tile/include/asm/Kbuild b/arch/tile/include/asm/Kbuild
index 3793c75e45d9..09699d5bff11 100644
--- a/arch/tile/include/asm/Kbuild
+++ b/arch/tile/include/asm/Kbuild
@@ -16,6 +16,7 @@ generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += local.h
 generic-y += local64.h
 generic-y += msgbuf.h
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
index 88a330dcdede..bd0b7a01e347 100644
--- a/arch/um/include/asm/Kbuild
+++ b/arch/um/include/asm/Kbuild
@@ -5,4 +5,5 @@ generic-y += switch_to.h clkdev.h
 generic-y += trace_clock.h
 generic-y += preempt.h
 generic-y += hash.h
+generic-y += irq_work.h
 generic-y += barrier.h
diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild
index 3ef4f9d9bf5d..9c0dd4327960 100644
--- a/arch/unicore32/include/asm/Kbuild
+++ b/arch/unicore32/include/asm/Kbuild
@@ -21,6 +21,7 @@ generic-y += ioctl.h
 generic-y += ioctls.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += local.h
diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild
index 7f669853317a..1eb77ac0613c 100644
--- a/arch/x86/include/asm/Kbuild
+++ b/arch/x86/include/asm/Kbuild
@@ -5,3 +5,4 @@ genhdr-y += unistd_64.h
 genhdr-y += unistd_x32.h
 
 generic-y += clkdev.h
+generic-y += irq_work.h
diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild
index 0a337e4a8370..b749817b4440 100644
--- a/arch/xtensa/include/asm/Kbuild
+++ b/arch/xtensa/include/asm/Kbuild
@@ -11,6 +11,7 @@ generic-y += fcntl.h
 generic-y += hardirq.h
 generic-y += ioctl.h
 generic-y += irq_regs.h
+generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += kmap_types.h
 generic-y += kvm_para.h
diff --git a/include/asm-generic/irq_work.h b/include/asm-generic/irq_work.h
new file mode 100644
index 000000000000..a44f452c6590
--- /dev/null
+++ b/include/asm-generic/irq_work.h
@@ -0,0 +1,10 @@
+#ifndef __ASM_IRQ_WORK_H
+#define __ASM_IRQ_WORK_H
+
+static inline bool arch_irq_work_has_interrupt(void)
+{
+	return false;
+}
+
+#endif /* __ASM_IRQ_WORK_H */
+
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 60c19eeca9e0..4a8c7a2df480 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -33,9 +33,12 @@ void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))
 
 void irq_work_queue(struct irq_work *work);
 void irq_work_run(void);
+void irq_work_tick(void);
 void irq_work_sync(struct irq_work *work);
 
 #ifdef CONFIG_IRQ_WORK
+#include <asm/irq_work.h>
+
 bool irq_work_needs_cpu(void);
 #else
 static inline bool irq_work_needs_cpu(void) { return false; }
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 5f7d93d89c7f..af8ceafc94e4 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -20,11 +20,8 @@
 #include <asm/processor.h>
 
 
-static DEFINE_PER_CPU(struct llist_head, irq_work_list);
-#ifdef CONFIG_PREEMPT_RT_FULL
-static DEFINE_PER_CPU(struct llist_head, hirq_work_list);
-#endif
-static DEFINE_PER_CPU(int, irq_work_raised);
+static DEFINE_PER_CPU(struct llist_head, raised_list);
+static DEFINE_PER_CPU(struct llist_head, lazy_list);
 
 /*
  * Claim the entry so that no one else will poke at it.
@@ -67,6 +64,9 @@ void __weak arch_irq_work_raise(void)
  */
 void irq_work_queue(struct irq_work *work)
 {
+	bool lazy_work, realtime = IS_ENABLED(CONFIG_PREEMPT_RT_FULL);
+	struct llist_head *list;
+
 	/* Only queue if not already pending */
 	if (!irq_work_claim(work))
 		return;
@@ -74,19 +74,16 @@ void irq_work_queue(struct irq_work *work)
 	/* Queue the entry and raise the IPI if needed. */
 	preempt_disable();
 
-#ifdef CONFIG_PREEMPT_RT_FULL
-	if (work->flags & IRQ_WORK_HARD_IRQ)
-		llist_add(&work->llnode, &__get_cpu_var(hirq_work_list));
+	/* If the work is "lazy", handle it from next tick if any */
+	lazy_work = work->flags & IRQ_WORK_LAZY;
+
+	if (lazy_work || (realtime && !(work->flags & IRQ_WORK_HARD_IRQ)))
+		list = this_cpu_ptr(&lazy_list);
 	else
-#endif
-		llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
-	/*
-	 * If the work is not "lazy" or the tick is stopped, raise the irq
-	 * work interrupt (if supported by the arch), otherwise, just wait
-	 * for the next tick.
-	 */
-	if (!(work->flags & IRQ_WORK_LAZY) || tick_nohz_tick_stopped()) {
-		if (!this_cpu_cmpxchg(irq_work_raised, 0, 1))
+		list = this_cpu_ptr(&raised_list);
+
+	if (llist_add(&work->llnode, list)) {
+		if (!lazy_work || tick_nohz_tick_stopped())
 			arch_irq_work_raise();
 	}
 
@@ -96,10 +93,11 @@ EXPORT_SYMBOL_GPL(irq_work_queue);
 
 bool irq_work_needs_cpu(void)
 {
-	struct llist_head *this_list;
+	struct llist_head *raised, *lazy;
 
-	this_list = &__get_cpu_var(irq_work_list);
-	if (llist_empty(this_list))
+	raised = &__get_cpu_var(raised_list);
+	lazy = &__get_cpu_var(lazy_list);
+	if (llist_empty(raised) && llist_empty(lazy))
 		return false;
 
 	/* All work should have been flushed before going offline */
@@ -108,34 +106,18 @@ bool irq_work_needs_cpu(void)
 	return true;
 }
 
-static void __irq_work_run(void)
+static void irq_work_run_list(struct llist_head *list)
 {
 	unsigned long flags;
 	struct irq_work *work;
-	struct llist_head *this_list;
 	struct llist_node *llnode;
 
+	BUG_ON_NONRT(!irqs_disabled());
 
-	/*
-	 * Reset the "raised" state right before we check the list because
-	 * an NMI may enqueue after we find the list empty from the runner.
-	 */
-	__this_cpu_write(irq_work_raised, 0);
-	barrier();
-
-#ifdef CONFIG_PREEMPT_RT_FULL
-	if (in_irq())
-		this_list = &__get_cpu_var(hirq_work_list);
-	else
-#endif
-		this_list = &__get_cpu_var(irq_work_list);
-	if (llist_empty(this_list))
+	if (llist_empty(list))
 		return;
 
-#ifndef CONFIG_PREEMPT_RT_FULL
-	BUG_ON(!irqs_disabled());
-#endif
-	llnode = llist_del_all(this_list);
+	llnode = llist_del_all(list);
 	while (llnode != NULL) {
 		work = llist_entry(llnode, struct irq_work, llnode);
 
@@ -166,13 +148,24 @@ static void __irq_work_run(void)
  */
 void irq_work_run(void)
 {
-#ifndef CONFIG_PREEMPT_RT_FULL
-	BUG_ON(!in_irq());
-#endif
-	__irq_work_run();
+	irq_work_run_list(this_cpu_ptr(&raised_list));
+	if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) {
+		if (!llist_empty(this_cpu_ptr(&lazy_list)))
+			raise_softirq(TIMER_SOFTIRQ);
+	} else
+		irq_work_run_list(this_cpu_ptr(&lazy_list));
 }
 EXPORT_SYMBOL_GPL(irq_work_run);
 
+void irq_work_tick(void)
+{
+	struct llist_head *raised = this_cpu_ptr(&raised_list);
+
+	if (!llist_empty(raised) && !arch_irq_work_has_interrupt())
+		irq_work_run_list(raised);
+	irq_work_run_list(this_cpu_ptr(&lazy_list));
+}
+
 /*
  * Synchronize against the irq_work @entry, ensures the entry is not
  * currently in use.
@@ -197,7 +190,7 @@ static int irq_work_cpu_notify(struct notifier_block *self,
 		/* Called from stop_machine */
 		if (WARN_ON_ONCE(cpu != smp_processor_id()))
 			break;
-		__irq_work_run();
+		irq_work_tick();
 		break;
 	default:
 		break;
diff --git a/kernel/timer.c b/kernel/timer.c
index 36b9f10bb3c7..300870358b4f 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1467,7 +1467,7 @@ static void run_timer_softirq(struct softirq_action *h)
 	hrtimer_run_pending();
 
 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
-	irq_work_run();
+	irq_work_tick();
 #endif
 
 	if (time_after_eq(jiffies, base->timer_jiffies))
diff --git a/localversion-rt b/localversion-rt
index 8bdfb9a04683..ac4d836a809d 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt42
+-rt44