Files
linux/kernel
Tejun Heo 9350558564 workqueue: skip nr_running sanity check in worker_enter_idle() if trustee is active
commit 544ecf310f upstream.

worker_enter_idle() has WARN_ON_ONCE() which triggers if nr_running
isn't zero when every worker is idle.  This can trigger spuriously
while a cpu is going down due to the way trustee sets %WORKER_ROGUE
and zaps nr_running.

It first sets %WORKER_ROGUE on all workers without updating
nr_running, releases gcwq->lock, schedules, regrabs gcwq->lock and
then zaps nr_running.  If the last running worker enters idle
inbetween, it would see stale nr_running which hasn't been zapped yet
and trigger the WARN_ON_ONCE().

Fix it by performing the sanity check iff the trustee is idle.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-01 15:12:56 +08:00
..
2011-08-04 21:58:35 -07:00
2011-03-31 11:26:23 -03:00
2011-03-14 09:15:23 -04:00
2010-10-30 01:42:19 -04:00
2011-05-19 18:51:57 +10:00
2011-05-17 23:19:17 +02:00
2011-03-31 11:26:23 -03:00
2011-05-26 17:12:34 -07:00
2012-04-02 09:27:20 -07:00
2011-05-26 17:12:34 -07:00
2011-03-31 11:26:23 -03:00
2011-04-18 10:35:30 -07:00
2011-05-24 12:10:51 +02:00
2011-05-20 12:50:29 -07:00
2011-03-31 11:26:23 -03:00
2011-04-24 13:18:38 +02:00
2011-03-23 19:46:51 -07:00
2011-12-21 12:57:40 -08:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00