From 08f503b0c089968b2542659a89dfd50c5c59bb0b Mon Sep 17 00:00:00 2001 From: Gregory Haskins Date: Mon, 10 Mar 2008 17:59:11 -0400 Subject: [PATCH] keep rd->online and cpu_online_map in sync It is possible to allow the root-domain cache of online cpus to become out of sync with the global cpu_online_map. This is because we currently trigger removal of cpus too early in the notifier chain. Other DOWN_PREPARE handlers may in fact run and reconfigure the root-domain topology, thereby stomping on our own offline handling. The end result is that rd->online may become out of sync with cpu_online_map, which results in potential task misrouting. So change the offline handling to be more tightly coupled with the global offline process by triggering on CPU_DYING intead of CPU_DOWN_PREPARE. Signed-off-by: Gregory Haskins Cc: Gautham R Shenoy Cc: "Siddha, Suresh B" Cc: "Rafael J. Wysocki" Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/sched.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched.c b/kernel/sched.c index 52b98675acb2..1cb53fb1fe3d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5881,7 +5881,8 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) spin_unlock_irq(&rq->lock); break; - case CPU_DOWN_PREPARE: + case CPU_DYING: + case CPU_DYING_FROZEN: /* Update our root-domain */ rq = cpu_rq(cpu); spin_lock_irqsave(&rq->lock, flags); -- 2.20.1