workqueue: Minor follow-ups to the rescuer destruction change

* 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>
This commit is contained in:
Tejun Heo 2019-09-20 14:09:14 -07:00
parent 8efe1223d7
commit 30ae2fc0a7

View File

@ -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);