workqueue: clear leftover flags when detached
When a worker is detached, the worker->flags may still have WORKER_UNBOUND
or WORKER_REBOUND, it is OK for all cases:
1) if it is a normal worker, the worker will be dead, it is OK.
2) if it is a rescuer, it may re-attach to a pool with this leftover flag[s],
it is still correct except it may cause unneeded wakeup.
It is correct but not good, so we just remove the leftover flags.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 4cfcd02..4f8d72d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1663,6 +1663,9 @@
detach_completion = pool->detach_completion;
mutex_unlock(&pool->attach_mutex);
+ /* clear leftover flags without pool->lock after it is detached */
+ worker->flags &= ~(WORKER_UNBOUND | WORKER_REBOUND);
+
if (detach_completion)
complete(detach_completion);
}