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From: Lai Jiangshan <eag0628@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/7 V6] workqueue: fix idle worker depletion
Date: Sun, 9 Sep 2012 02:34:02 +0800	[thread overview]
Message-ID: <CACvQF51PY95Eg+DLhZ4ZRRNK0x9q+pOzrPfZbhTnPvk35j8PNg@mail.gmail.com> (raw)
In-Reply-To: <20120908181107.GJ10788@dhcp-172-17-108-109.mtv.corp.google.com>

On Sun, Sep 9, 2012 at 2:11 AM, Tejun Heo <tj@kernel.org> wrote:
> On Sun, Sep 09, 2012 at 02:07:50AM +0800, Lai Jiangshan wrote:
>> when we release gcwq->lock and then grab it, we leave a hole that things
>> can be changed.
>>
>> I don't want to open a hole. if the hole has bug we have to fix it.
>> if the hole has no bug, we have to add lot of comments to explain it.
>>
>> When I write this reply. I am thinking: is the hole  has bug if
>> I release gcwq->lock here? result: no. But I don't want to add all things
>> what I have thought as comments to explain there is no bug even when we
>> open a hole. don't leave reviewers too much burden.
>
> We're already releasing gcwq->lock in maybe_create_worker().  That's
> the reason why @ret is set to true.  In addition, we already released
> the lock to grab manager_mutex.  So, you're not adding any burden.
> Please reuse the busy rebinding mechanism.
>

in 3.6 busy_worker_rebind() handle WORKER_REBIND bit,
not WORKER_UNBOUND bit.

busy_worker_rebind() takes struct work_struct *work argument, we have to
add new patch to add a helper and restruct it at first.

worker_maybe_bind_and_lock() 's mean is very clear here. busy_worker_rebind()
seems for busy workers, manager is not busy workers.

>
> --
> tejun

  reply	other threads:[~2012-09-08 18:34 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-08 17:12 [PATCH 0/7 V6] workqueue: fix hoplug things Lai Jiangshan
2012-09-08 17:12 ` [PATCH 1/7 V6] workqueue: ensure the wq_worker_sleeping() see the right flags Lai Jiangshan
2012-09-08 17:12 ` [PATCH 2/7 V6] workqueue: async idle rebinding Lai Jiangshan
2012-09-08 17:12 ` [PATCH 3/7 V6] workqueue: add manager pointer for worker_pool Lai Jiangshan
2012-09-08 17:12 ` [PATCH 4/7 V6] workqueue: fix idle worker depletion Lai Jiangshan
2012-09-08 17:40   ` Tejun Heo
2012-09-08 17:50     ` Lai Jiangshan
2012-09-08 17:53       ` Tejun Heo
2012-09-08 18:07         ` Lai Jiangshan
2012-09-08 18:11           ` Tejun Heo
2012-09-08 18:34             ` Lai Jiangshan [this message]
2012-09-08 19:02               ` Tejun Heo
2012-09-09  4:09                 ` Lai Jiangshan
2012-09-09  6:30                   ` Tejun Heo
2012-09-08 17:12 ` [PATCH 5/7 V6] workqueue: rename manager_mutex to assoc_mutex Lai Jiangshan
2012-09-08 17:12 ` [PATCH 6/7 V6] workqueue: new day don't need WORKER_REBIND for busy rebinding Lai Jiangshan
2012-09-08 17:12 ` [PATCH 7/7 V6] workqueue: remove WORKER_REBIND Lai Jiangshan
2012-09-08 17:27 ` [PATCH 0/7 V6] workqueue: fix hoplug things Lai Jiangshan
2012-09-08 17:34   ` Lai Jiangshan
2012-09-08 17:37   ` Tejun Heo
2012-09-08 17:46     ` Lai Jiangshan
2012-09-08 17:50       ` Tejun Heo
2012-09-08 17:51         ` Tejun Heo
2012-09-08 17:56         ` Lai Jiangshan
2012-09-08 17:59           ` Tejun Heo
2012-09-08 18:21             ` Lai Jiangshan

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