workqueue: note the nested NOT_RUNNING test in worker_clr_flags() isn't a noop
The nested NOT_RUNNING test in worker_clr_flags() is slightly
misleading in that if NOT_RUNNING were a single flag the nested test
would be always %true and thus noop. Add a comment noting that the
test isn't a noop.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 930c239..11869fa 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -768,7 +768,11 @@
worker->flags &= ~flags;
- /* if transitioning out of NOT_RUNNING, increment nr_running */
+ /*
+ * If transitioning out of NOT_RUNNING, increment nr_running. Note
+ * that the nested NOT_RUNNING is not a noop. NOT_RUNNING is mask
+ * of multiple flags, not a single flag.
+ */
if ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING))
if (!(worker->flags & WORKER_NOT_RUNNING))
atomic_inc(get_gcwq_nr_running(gcwq->cpu));