Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  cpu: Export cpu_up()
  rcu: Apply ACCESS_ONCE() to rcu_boost() return value
  Revert "rcu: Permit rt_mutex_unlock() with irqs disabled"
  docs: Additional LWN links to RCU API
  rcu: Augment rcu_batch_end tracing for idle and callback state
  rcu: Add rcutorture tests for srcu_read_lock_raw()
  rcu: Make rcutorture test for hotpluggability before offlining CPUs
  driver-core/cpu: Expose hotpluggability to the rest of the kernel
  rcu: Remove redundant rcu_cpu_stall_suppress declaration
  rcu: Adaptive dyntick-idle preparation
  rcu: Keep invoking callbacks if CPU otherwise idle
  rcu: Irq nesting is always 0 on rcu_enter_idle_common
  rcu: Don't check irq nesting from rcu idle entry/exit
  rcu: Permit dyntick-idle with callbacks pending
  rcu: Document same-context read-side constraints
  rcu: Identify dyntick-idle CPUs on first force_quiescent_state() pass
  rcu: Remove dynticks false positives and RCU failures
  rcu: Reduce latency of rcu_prepare_for_idle()
  rcu: Eliminate RCU_FAST_NO_HZ grace-period hang
  rcu: Avoid needlessly IPIing CPUs at GP end
  ...

arch/x86/kernel/apic/apic.c

@@ -876,8 +876,8 @@ void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
 	 * Besides, if we don't timer interrupts ignore the global
 	 * interrupt lock, which is the WrongThing (tm) to do.
 	 */
-	exit_idle();
 	irq_enter();
+	exit_idle();
 	local_apic_timer_interrupt();
 	irq_exit();
 
@@ -1809,8 +1809,8 @@ void smp_spurious_interrupt(struct pt_regs *regs)
 {
 	u32 v;
 
-	exit_idle();
 	irq_enter();
+	exit_idle();
 	/*
 	 * Check if this really is a spurious interrupt and ACK it
 	 * if it is a vectored one.  Just in case...
@@ -1846,8 +1846,8 @@ void smp_error_interrupt(struct pt_regs *regs)
 		"Illegal register address",	/* APIC Error Bit 7 */
 	};
 
-	exit_idle();
 	irq_enter();
+	exit_idle();
 	/* First tickle the hardware, only then report what went on. -- REW */
 	v0 = apic_read(APIC_ESR);
 	apic_write(APIC_ESR, 0);

arch/x86/kernel/apic/io_apic.c

@@ -2421,8 +2421,8 @@ asmlinkage void smp_irq_move_cleanup_interrupt(void)
 	unsigned vector, me;
 
 	ack_APIC_irq();
-	exit_idle();
 	irq_enter();
+	exit_idle();
 
 	me = smp_processor_id();
 	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {

arch/x86/kernel/cpu/mcheck/therm_throt.c

@@ -397,8 +397,8 @@ static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
 
 asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
 {
-	exit_idle();
 	irq_enter();
+	exit_idle();
 	inc_irq_stat(irq_thermal_count);
 	smp_thermal_vector();
 	irq_exit();

arch/x86/kernel/cpu/mcheck/threshold.c

@@ -19,8 +19,8 @@ void (*mce_threshold_vector)(void) = default_threshold_interrupt;
 
 asmlinkage void smp_threshold_interrupt(void)
 {
-	exit_idle();
 	irq_enter();
+	exit_idle();
 	inc_irq_stat(irq_threshold_count);
 	mce_threshold_vector();
 	irq_exit();

arch/x86/kernel/irq.c

@@ -181,8 +181,8 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 	unsigned vector = ~regs->orig_ax;
 	unsigned irq;
 
-	exit_idle();
 	irq_enter();
+	exit_idle();
 
 	irq = __this_cpu_read(vector_irq[vector]);
 
@@ -209,10 +209,10 @@ void smp_x86_platform_ipi(struct pt_regs *regs)
 
 	ack_APIC_irq();
 
-	exit_idle();
-
 	irq_enter();
 
+	exit_idle();
+
 	inc_irq_stat(x86_platform_ipis);
 
 	if (x86_platform_ipi_callback)

arch/x86/kernel/process_32.c

@@ -99,7 +99,8 @@ void cpu_idle(void)
 
 	/* endless idle loop with no priority at all */
 	while (1) {
-		tick_nohz_stop_sched_tick(1);
+		tick_nohz_idle_enter();
+		rcu_idle_enter();
 		while (!need_resched()) {
 
 			check_pgt_cache();
@@ -116,7 +117,8 @@ void cpu_idle(void)
 				pm_idle();
 			start_critical_timings();
 		}
-		tick_nohz_restart_sched_tick();
+		rcu_idle_exit();
+		tick_nohz_idle_exit();
 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();

arch/x86/kernel/process_64.c

@@ -122,7 +122,7 @@ void cpu_idle(void)
 
 	/* endless idle loop with no priority at all */
 	while (1) {
-		tick_nohz_stop_sched_tick(1);
+		tick_nohz_idle_enter();
 		while (!need_resched()) {
 
 			rmb();
@@ -139,8 +139,14 @@ void cpu_idle(void)
 			enter_idle();
 			/* Don't trace irqs off for idle */
 			stop_critical_timings();
+
+			/* enter_idle() needs rcu for notifiers */
+			rcu_idle_enter();
+
 			if (cpuidle_idle_call())
 				pm_idle();
+
+			rcu_idle_exit();
 			start_critical_timings();
 
 			/* In many cases the interrupt that ended idle
@@ -149,7 +155,7 @@ void cpu_idle(void)
 			__exit_idle();
 		}
 
-		tick_nohz_restart_sched_tick();
+		tick_nohz_idle_exit();
 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();