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
  ...

7 files changed, 21 insertions, 13 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index f98d84caf94c..2cd2d93643dc 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/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);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 6d939d7847e2..898055585516 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/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++) {
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index 787e06c84ea6..ce215616d5b9 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/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();
diff --git a/arch/x86/kernel/cpu/mcheck/threshold.c b/arch/x86/kernel/cpu/mcheck/threshold.c
index d746df2909c9..aa578cadb940 100644
--- a/arch/x86/kernel/cpu/mcheck/threshold.c
+++ b/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();
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 429e0c92924e..5d31e5bdbf85 100644
--- a/arch/x86/kernel/irq.c
+++ b/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)
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 795b79f984c2..485204f58cda 100644
--- a/arch/x86/kernel/process_32.c
+++ b/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();
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 3bd7e6eebf31..64e926c89a6f 100644
--- a/arch/x86/kernel/process_64.c
+++ b/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();