[PATCH] workqueue: Minor follow-ups to the rescuer destruction change

[Tejun Heo <tj@kernel.org>]

From 30ae2fc0a75eb5f1a38bbee7355d8e3bc823a6e1 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Fri, 20 Sep 2019 14:09:14 -0700

* Now that wq->rescuer may be cleared while rescuer is still there,
  switch show_pwq() debug printout to test worker->rescue_wq to
  identify rescuers intead of testing wq->rescuer.

* Update comment on ->rescuer locking.

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com>
---
Applied to workqueue/for-5.4-fixes.

Thanks.

 kernel/workqueue.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 3f067f1d72e3..7f7aa45dac37 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -248,7 +248,7 @@ struct workqueue_struct {
 	struct list_head	flusher_overflow; /* WQ: flush overflow list */
 
 	struct list_head	maydays;	/* MD: pwqs requesting rescue */
-	struct worker		*rescuer;	/* I: rescue worker */
+	struct worker		*rescuer;	/* MD: rescue worker */
 
 	int			nr_drainers;	/* WQ: drain in progress */
 	int			saved_max_active; /* WQ: saved pwq max_active */
@@ -4672,7 +4672,7 @@ static void show_pwq(struct pool_workqueue *pwq)
 
 			pr_cont("%s %d%s:%ps", comma ? "," : "",
 				task_pid_nr(worker->task),
-				worker == pwq->wq->rescuer ? "(RESCUER)" : "",
+				worker->rescue_wq ? "(RESCUER)" : "",
 				worker->current_func);
 			list_for_each_entry(work, &worker->scheduled, entry)
 				pr_cont_work(false, work);
-- 
2.17.1