Merge remote-tracking branch 'rcu/rcu/next'

[deliverable/linux.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a0086a5fc00893d63f1b0c42ac85f63508d07a2d..f5f7b3cdf0be0577d69fc44e4390e7d9a1e75c88 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -581,6 +581,8 @@ static bool wake_up_full_nohz_cpu(int cpu)
         * If needed we can still optimize that later with an
         * empty IRQ.
         */
+       if (cpu_is_offline(cpu))
+               return true;  /* Don't try to wake offline CPUs. */
        if (tick_nohz_full_cpu(cpu)) {
                if (cpu != smp_processor_id() ||
                    tick_nohz_tick_stopped())
@@ -591,6 +593,11 @@ static bool wake_up_full_nohz_cpu(int cpu)
        return false;
 }
 
+/*
+ * Wake up the specified CPU.  If the CPU is going offline, it is the
+ * caller's responsibility to deal with the lost wakeup, for example,
+ * by hooking into the CPU_DEAD notifier like timers and hrtimers do.
+ */
 void wake_up_nohz_cpu(int cpu)
 {
        if (!wake_up_full_nohz_cpu(cpu))