workqueue: Remove useless pool->dying_workers

A dying worker is first moved from pool->workers to pool->dying_workers
in set_worker_dying() and removed from pool->dying_workers in
detach_dying_workers().  The whole procedure is in the some lock context
of wq_pool_attach_mutex.

So pool->dying_workers is useless, just remove it and keep the dying
worker in pool->workers after set_worker_dying() and remove it in
detach_dying_workers() with wq_pool_attach_mutex held.

Cc: Valentin Schneider <vschneid@redhat.com>
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 04168972814bbc520cb061156bec1612496510f9..adf1893b161ee5d8a01e3a98a19595a38b0a02c0 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -215,7 +215,6 @@ struct worker_pool {
 
        struct worker           *manager;       /* L: purely informational */
        struct list_head        workers;        /* A: attached workers */
-       struct list_head        dying_workers;  /* A: workers about to die */
 
        struct ida              worker_ida;     /* worker IDs for task name */
 
@@ -2862,7 +2861,6 @@ static void set_worker_dying(struct worker *worker, struct list_head *list)
        worker->flags |= WORKER_DIE;
 
        list_move(&worker->entry, list);
-       list_move(&worker->node, &pool->dying_workers);
 
        /* get an extra task struct reference for later kthread_stop_put() */
        get_task_struct(worker->task);
@@ -4721,7 +4719,6 @@ static int init_worker_pool(struct worker_pool *pool)
        timer_setup(&pool->mayday_timer, pool_mayday_timeout, 0);
 
        INIT_LIST_HEAD(&pool->workers);
-       INIT_LIST_HEAD(&pool->dying_workers);
 
        ida_init(&pool->worker_ida);
        INIT_HLIST_NODE(&pool->hash_node);