From c0ab017d43f4c4147f7ecf3ca3cb872a416e17c7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 7 Aug 2023 15:57:22 -1000 Subject: [PATCH] workqueue: Cleanups around process_scheduled_works() * Drop the trivial optimization in worker_thread() where it bypasses calling process_scheduled_works() if the first work item isn't linked. This is a mostly pointless micro optimization and gets in the way of improving the work processing path. * Consolidate pool->watchdog_ts updates in the two callers into process_scheduled_works(). Signed-off-by: Tejun Heo --- kernel/workqueue.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 598009a..20722de 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2652,9 +2652,15 @@ __acquires(&pool->lock) */ static void process_scheduled_works(struct worker *worker) { - while (!list_empty(&worker->scheduled)) { - struct work_struct *work = list_first_entry(&worker->scheduled, - struct work_struct, entry); + struct work_struct *work; + bool first = true; + + while ((work = list_first_entry_or_null(&worker->scheduled, + struct work_struct, entry))) { + if (first) { + worker->pool->watchdog_ts = jiffies; + first = false; + } process_one_work(worker, work); } } @@ -2735,17 +2741,8 @@ recheck: list_first_entry(&pool->worklist, struct work_struct, entry); - pool->watchdog_ts = jiffies; - - if (likely(!(*work_data_bits(work) & WORK_STRUCT_LINKED))) { - /* optimization path, not strictly necessary */ - process_one_work(worker, work); - if (unlikely(!list_empty(&worker->scheduled))) - process_scheduled_works(worker); - } else { - move_linked_works(work, &worker->scheduled, NULL); - process_scheduled_works(worker); - } + move_linked_works(work, &worker->scheduled, NULL); + process_scheduled_works(worker); } while (keep_working(pool)); worker_set_flags(worker, WORKER_PREP); @@ -2820,7 +2817,6 @@ repeat: struct pool_workqueue, mayday_node); struct worker_pool *pool = pwq->pool; struct work_struct *work, *n; - bool first = true; __set_current_state(TASK_RUNNING); list_del_init(&pwq->mayday_node); @@ -2838,12 +2834,9 @@ repeat: WARN_ON_ONCE(!list_empty(scheduled)); list_for_each_entry_safe(work, n, &pool->worklist, entry) { if (get_work_pwq(work) == pwq) { - if (first) - pool->watchdog_ts = jiffies; move_linked_works(work, scheduled, &n); pwq->stats[PWQ_STAT_RESCUED]++; } - first = false; } if (!list_empty(scheduled)) { -- 2.7.4