All of lore.kernel.org
 help / color / mirror / Atom feed
From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Tejun Heo <tj@kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2 V3] workqueue: substitute POOL_FREEZING with __WQ_FREEZING
Date: Wed, 23 Apr 2014 09:37:28 +0800	[thread overview]
Message-ID: <53571958.7050606@cn.fujitsu.com> (raw)
In-Reply-To: <20140422204623.GC3615@mtj.dyndns.org>

On 04/23/2014 04:46 AM, Tejun Heo wrote:
> Hello,
> 
> On Tue, Apr 22, 2014 at 09:47:47AM +0800, Lai Jiangshan wrote:
>> Testing workqueue_freezing requires wq_pool_mutex held.
>> Although almost-all pwq_adjust_max_active() are called with wq_pool_mutex held,
>> except workqueue_set_max_active(). But I hope pwq_adjust_max_active()
>> don't require the heavy wq_pool_mutex.
> 
> No it doesn't require wq_pool_mutex to be held.  All it requires is
> that the changed state is visible on the subsequent
> pwq_adjust_max_active() invocatino which is already trivially
> guaranteed.
> 

Good! I understood! Could you respin the patch? I'm afraid
I can't explain it well in the comments.

For me, I always prefer locks for non-performance critical path,
locks help review, I believe your comment will do so.

Thanks,
Lai

      reply	other threads:[~2014-04-23  1:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-21 11:59 [PATCH 1/2 V3] workqueue: substitute POOL_FREEZING with __WQ_FREEZING Lai Jiangshan
2014-04-21 11:59 ` [PATCH 2/2 V3] workqueue: simple refactor pwq_adjust_max_active() Lai Jiangshan
2014-04-21 22:20 ` [PATCH 1/2 V3] workqueue: substitute POOL_FREEZING with __WQ_FREEZING Tejun Heo
2014-04-22  1:47   ` Lai Jiangshan
2014-04-22 20:46     ` Tejun Heo
2014-04-23  1:37       ` Lai Jiangshan [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=53571958.7050606@cn.fujitsu.com \
    --to=laijs@cn.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tj@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.