workqueue: Only assign rescuer work when really needed

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>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0e5ec6e002b1a7ee52e47211a6203b6797ff89ed..656715d216b49958619ea981542a21cfcbc5fbc4 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3442,6 +3442,10 @@ 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.