diff options
| author | Tejun Heo <tj@kernel.org> | 2012-05-14 15:04:50 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-06-01 15:18:19 +0800 |
| commit | 24312d34c95702e51240f58c073db30630170fbf (patch) | |
| tree | 9f3849204b3211e270397ac75f52b57bebca2892 /mm | |
| parent | 9ed2cb7819e7df0e0fe0cce574c64e57b4806fe1 (diff) | |
workqueue: skip nr_running sanity check in worker_enter_idle() if trustee is active
commit 544ecf310f0e7f51fa057ac2a295fc1b3b35a9d3 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>
Diffstat (limited to 'mm')
0 files changed, 0 insertions, 0 deletions