sched: Fix hotplug hang
The hot-unplug kstopmachine usage does a wakeup after
deactivating the cpu, hence we cannot use cpu_active()
here but must rely on the good olde online.
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <1261326987.4314.24.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 7ffde2a..87f1f47 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2346,7 +2346,7 @@
* not worry about this generic constraint ]
*/
if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) ||
- !cpu_active(cpu)))
+ !cpu_online(cpu)))
cpu = select_fallback_rq(task_cpu(p), p);
return cpu;