workqueue: wake up a worker when a rescuer is leaving a gcwq
After executing the matching works, a rescuer leaves the gcwq whether
there are more pending works or not. This may decrease the
concurrency level to zero and stall execution until a new work item is
queued on the gcwq.
Make rescuer wake up a regular worker when it leaves a gcwq if there
are more works to execute, so that execution isn't stalled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ray Jui <rjui@broadcom.com>
Cc: stable@kernel.org
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 11869fa..90a17ca 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2047,6 +2047,15 @@
move_linked_works(work, scheduled, &n);
process_scheduled_works(rescuer);
+
+ /*
+ * Leave this gcwq. If keep_working() is %true, notify a
+ * regular worker; otherwise, we end up with 0 concurrency
+ * and stalling the execution.
+ */
+ if (keep_working(gcwq))
+ wake_up_worker(gcwq);
+
spin_unlock_irq(&gcwq->lock);
}
