Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul E. McKenney:

  - Documentation updates.

  - Changes permitting use of call_rcu() and friends very early in
    boot, for example, before rcu_init() is invoked.

  - Miscellaneous fixes.

  - Add in-kernel API to enable and disable expediting of normal RCU
    grace periods.

  - Improve RCU's handling of (hotplug-) outgoing CPUs.

    Note: ARM support is lagging a bit here, and these improved
    diagnostics might generate (harmless) splats.

  - NO_HZ_FULL_SYSIDLE fixes.

  - Tiny RCU updates to make it more tiny.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 80014a178342..d27d36476dca 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -210,6 +210,8 @@ use_default:
         goto exit_idle;
 }
 
+DEFINE_PER_CPU(bool, cpu_dead_idle);
+
 /*
  * Generic idle loop implementation
  *
@@ -234,8 +236,13 @@ static void cpu_idle_loop(void)
                         check_pgt_cache();
                         rmb();
 
-                        if (cpu_is_offline(smp_processor_id()))
+                        if (cpu_is_offline(smp_processor_id())) {
+                                rcu_cpu_notify(NULL, CPU_DYING_IDLE,
+                                               (void *)(long)smp_processor_id());
+                                smp_mb(); /* all activity before dead. */
+                                this_cpu_write(cpu_dead_idle, true);
                                 arch_cpu_idle_dead();
+                        }
 
                         local_irq_disable();
                         arch_cpu_idle_enter();