From 88428cc5c27c63a4313e213813bc39b9899224d5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 28 Jan 2015 14:42:09 -0800 Subject: rcu: Handle outgoing CPUs on exit from idle loop This commit informs RCU of an outgoing CPU just before that CPU invokes arch_cpu_idle_dead() during its last pass through the idle loop (via a new CPU_DYING_IDLE notifier value). This change means that RCU need not deal with outgoing CPUs passing through the scheduler after informing RCU that they are no longer online. Note that removing the CPU from the rcu_node ->qsmaskinit bit masks is done at CPU_DYING_IDLE time, and orphaning callbacks is still done at CPU_DEAD time, the reason being that at CPU_DEAD time we have another CPU that can adopt them. Signed-off-by: Paul E. McKenney --- kernel/sched/idle.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/sched') diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index e99e361ade20..b0090accfb5b 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -225,6 +225,8 @@ static void cpu_idle_loop(void) rmb(); 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(); -- cgit v1.2.1