[PATCH V3 2/7] workqueue: Only assign rescuer work when really needed

[Lai Jiangshan <jiangshanlai@gmail.com>]

From: Lai Jiangshan <jiangshan.ljs@antgroup.com>

If the pwq does not need rescue (normal workers have been created or
become available), the rescuer can immediately move on to other stalled
pwqs.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
---
 kernel/workqueue.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c60584a39fc9..932581d93edb 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3444,6 +3444,10 @@ static bool assign_rescuer_work(struct pool_workqueue *pwq, struct worker *rescu
 	struct worker_pool *pool = pwq->pool;
 	struct work_struct *work, *n;
 
+	/* need rescue? */
+	if (!pwq->nr_active || !need_to_create_worker(pool))
+		return false;
+
 	/*
 	 * Slurp in all works issued via this workqueue and
 	 * process'em.
-- 
2.19.1.6.gb485710b