Re: [PATCH 07/31] workqueue: restructure pool / pool_workqueue iterations in freeze/thaw functions

[Tejun Heo <tj@kernel.org>]

Hello, Lai.

On Sun, Mar 10, 2013 at 06:09:17PM +0800, Lai Jiangshan wrote:
> > +	/* clear FREEZING */
> > +	for_each_pool(pool, id) {
> > +		spin_lock(&pool->lock);
> > +		WARN_ON_ONCE(!(pool->flags & POOL_FREEZING));
> > +		pool->flags &= ~POOL_FREEZING;
> > +		spin_unlock(&pool->lock);
> > +	}
> 
> 
> I think it would be better if we move this code to ...
> 
> >  
> > -			wake_up_worker(pool);
> > +	/* restore max_active and repopulate worklist */
> > +	list_for_each_entry(wq, &workqueues, list) {
> > +		if (!(wq->flags & WQ_FREEZABLE))
> > +			continue;
> >  
> > -			spin_unlock(&pool->lock);
> > +		for_each_pwq(pwq, wq) {
> > +			spin_lock(&pwq->pool->lock);
> > +			pwq_set_max_active(pwq, wq->saved_max_active);
> > +			spin_unlock(&pwq->pool->lock);
> >  		}
> >  	}
> >  
> > +	/* kick workers */
> > +	for_each_pool(pool, id) {
> > +		spin_lock(&pool->lock);
> > +		wake_up_worker(pool);
> > +		spin_unlock(&pool->lock);
> > +	}
> 
> 
> ... to here.
> 
> clear FREEZING and then kick.

Yeah, that would be prettier but also change the order of operations
which I'd like to keep the same across the conversion.  We can create
a separate patch to merge the two loops later.  Care to send a
separate patch?

Thanks.

-- 
tejun