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From: Tejun Heo <tj@kernel.org>
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/7 V2] workqueue: simplify wq_update_unbound_numa()
Date: Mon, 18 May 2015 16:21:12 -0400	[thread overview]
Message-ID: <20150518202112.GC24861@htj.duckdns.org> (raw)
In-Reply-To: <1431433955-3173-3-git-send-email-laijs@cn.fujitsu.com>

On Tue, May 12, 2015 at 08:32:30PM +0800, Lai Jiangshan wrote:
> wq_update_unbound_numa() is known be called with wq_pool_mutex held.
> 
> But wq_update_unbound_numa() requests wq->mutex before reading
> wq->unbound_attrs, wq->numa_pwq_tbl[] and wq->dfl_pwq.  But these fields
> were changed to be allowed being read with wq_pool_mutex held.  So we
> simply remove the mutex_lock(&wq->mutex).
> 
> Without the dependence on the the mutex_lock(&wq->mutex), the test
> of wq->unbound_attrs->no_numa can also be moved upward.
> 
> The old code need a long comment to describe the stableness of
> @wq->unbound_attrs which is also guaranteed by wq_pool_mutex now,
> so we don't need this such comment.
> 
> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Applied 1-2 to wq/for-4.2.

Thanks.

-- 
tejun

  reply	other threads:[~2015-05-18 20:21 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-12 12:32 [PATCH 0/7 V2] workqueue: cleanup for attr management Lai Jiangshan
2015-05-12 12:32 ` [PATCH 1/7 V2] workqueue: wq_pool_mutex protects the attrs-installation Lai Jiangshan
2015-05-12 12:32 ` [PATCH 2/7 V2] workqueue: simplify wq_update_unbound_numa() Lai Jiangshan
2015-05-18 20:21   ` Tejun Heo [this message]
2015-05-12 12:32 ` [PATCH 3/7 V2] workqueue: introduce get_pwq_unlocked() Lai Jiangshan
2015-05-18 20:28   ` Tejun Heo
2015-05-18 20:41   ` Tejun Heo
2015-05-12 12:32 ` [PATCH 4/7 V2] workqueue: reuse the current per-node pwq when its attrs unchanged Lai Jiangshan
2015-05-18 20:34   ` Tejun Heo
2015-05-25  9:47   ` Lai Jiangshan
2015-05-26 18:51     ` Tejun Heo
2015-05-12 12:32 ` [PATCH 5/7 V2] workqueue: reuse the current default " Lai Jiangshan
2015-05-18 20:38   ` Tejun Heo
2015-05-12 12:32 ` [PATCH 6/7 V2] workqueue: reuse wq_update_unbound_numa_attrs_buf as temporary attrs Lai Jiangshan
2015-05-12 12:32 ` [PATCH 7/7 V2] workqueue: add get_node_unbound_pwq() Lai Jiangshan
2015-05-18  0:39 ` [PATCH 0/7 V2] workqueue: cleanup for attr management Lai Jiangshan
2015-05-18  1:26   ` Tejun Heo
2015-05-18  2:06     ` Lai Jiangshan

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