Messages in this thread | | | Date | Mon, 9 Oct 2017 07:47:02 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH workqueue/for-4.14-fixes] workqueue: replace pool->manager_arb mutex with a flag |
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Hello, Boqun.
On Mon, Oct 09, 2017 at 10:21:17PM +0800, Boqun Feng wrote: > > +static DECLARE_WAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */ > > I think this wait_queue_head better be a per-pool one rather than shared > among pools?
It should be fine either way. All the involved operations are pretty low frequency.
> > @@ -3338,7 +3332,10 @@ static void put_unbound_pool(struct worker_pool *pool) > > if (pool->detach_completion) > > wait_for_completion(pool->detach_completion); > > > > - mutex_unlock(&pool->manager_arb); > > + spin_lock_irq(&pool->lock); > > + pool->flags &= ~POOL_MANAGER_ACTIVE; > > + wake_up(&wq_manager_wait); > > + spin_unlock_irq(&pool->lock); > > > > Is the above code necesarry? IIUC, we are going to free the pool > entirely, so whether manager is active is pointless here and no one is > waiting for the ->flags of *this* pool to be !POOL_MANAGER_ACTIVE. > > Am I missing something subtle here?
Ah, true. I'll drop the above chunk.
Thanks.
-- tejun
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