lkml.org 
[lkml]   [2012]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 4/7 V6] workqueue: fix idle worker depletion
Hello, Lai.

On Sun, Sep 09, 2012 at 01:12:53AM +0800, Lai Jiangshan wrote:
> +/* does the manager need to be rebind after we just release gcwq->lock */
> +static void maybe_rebind_manager(struct worker *manager)
> +{
> + struct global_cwq *gcwq = manager->pool->gcwq;
> + bool assoc = !(gcwq->flags & GCWQ_DISASSOCIATED);
> +
> + if (assoc && (manager->flags & WORKER_UNBOUND)) {
> + spin_unlock_irq(&gcwq->lock);
> +
> + if (worker_maybe_bind_and_lock(manager))
> + worker_clr_flags(manager, WORKER_UNBOUND);
> + }
> +}

We can reuse busy_worker_rebind_fn(), right?

> pool->manager = worker;
> + if (unlikely(!mutex_trylock(&pool->manager_mutex))) {
> + /*
> + * Ouch! rebind_workers() or gcwq_unbind_fn() beats we.
> + * it can't return false here, otherwise it will lead to
> + * worker depletion. So we release gcwq->lock and then
> + * grab manager_mutex again.
> + */
> + spin_unlock_irq(&gcwq->lock);
> + mutex_lock(&pool->manager_mutex);
> + spin_lock_irq(&gcwq->lock);
> +
> + /* rebind_workers() can happen when we release gcwq->lock */
> + maybe_rebind_manager(worker);

And we can call process_scheduled_works() here and make the CPU
hotplug check pool->manager and schedule rebind_work there.

Thanks.

--
tejun


\
 
 \ /
  Last update: 2012-09-08 20:01    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site