Messages in this thread | | | Date | Sat, 8 Sep 2012 10:40:44 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH 4/7 V6] workqueue: fix idle worker depletion |
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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
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