Messages in this thread Patch in this message | | | Date | Wed, 3 Dec 2014 13:02:41 -0500 | From | Tejun Heo <> | Subject | Re: [PATCH - v3?] workqueue: allow rescuer thread to do more work. |
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So, something like the following. Only compile tested. I'll test it and post proper patches w/ due credits.
Thanks.
Index: work/kernel/workqueue.c =================================================================== --- work.orig/kernel/workqueue.c +++ work/kernel/workqueue.c @@ -1804,8 +1804,8 @@ static void pool_mayday_timeout(unsigned struct worker_pool *pool = (void *)__pool; struct work_struct *work; - spin_lock_irq(&wq_mayday_lock); /* for wq->maydays */ - spin_lock(&pool->lock); + spin_lock_irq(&pool->lock); + spin_lock(&wq_mayday_lock); /* for wq->maydays */ if (need_to_create_worker(pool)) { /* @@ -1818,8 +1818,8 @@ static void pool_mayday_timeout(unsigned send_mayday(work); } - spin_unlock(&pool->lock); - spin_unlock_irq(&wq_mayday_lock); + spin_unlock(&wq_mayday_lock); + spin_unlock_irq(&pool->lock); mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL); } @@ -2248,12 +2248,29 @@ repeat: * Slurp in all works issued via this workqueue and * process'em. */ - WARN_ON_ONCE(!list_empty(&rescuer->scheduled)); + WARN_ON_ONCE(!list_empty(scheduled)); list_for_each_entry_safe(work, n, &pool->worklist, entry) if (get_work_pwq(work) == pwq) move_linked_works(work, scheduled, &n); - process_scheduled_works(rescuer); + if (!list_empty(scheduled)) { + process_scheduled_works(rescuer); + + /* + * The above execution of rescued work items could + * have created more to rescue through + * pwq_activate_first_delayed() or chained + * queueing. Let's put @pwq back on mayday list so + * that such back-to-back work items, which may be + * being used to relieve memory pressure, don't + * incur MAYDAY_INTERVAL delay inbetween. + */ + if (need_to_create_worker(pool)) { + spin_lock(&wq_mayday_lock); + list_move_tail(&pwq->mayday_node, &wq->maydays); + spin_unlock(&wq_mayday_lock); + } + } /* * Put the reference grabbed by send_mayday(). @pool won't -- tejun
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