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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 02/13] workqueue: fix work_busy()
Date: Tue, 05 Feb 2013 20:06:54 +0800	[thread overview]
Message-ID: <5110F5DE.6030407@gmail.com> (raw)
In-Reply-To: <20130204195458.GA27963@mtj.dyndns.org>

于 2013/2/5 3:54, Tejun Heo 写道:
> Hello, Lai.
>
> On Fri, Feb 01, 2013 at 02:41:25AM +0800, Lai Jiangshan wrote:
>> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
>> index 973b290..d474a6c 100644
>> --- a/kernel/workqueue.c
>> +++ b/kernel/workqueue.c
>> @@ -3443,8 +3443,6 @@ EXPORT_SYMBOL_GPL(workqueue_congested);
>>    * Test whether @work is currently pending or running.  There is no
>>    * synchronization around this function and the test result is
>>    * unreliable and only useful as advisory hints or for debugging.
>> - * Especially for reentrant wqs, the pending state might hide the
>> - * running state.
>
> Yeap, this is no longer true.
>
>>    *
>>    * RETURNS:
>>    * OR'd bitmask of WORK_BUSY_* bits.
>> @@ -3453,15 +3451,13 @@ unsigned int work_busy(struct work_struct *work)
>>   {
>>   	struct worker_pool *pool = get_work_pool(work);
>>   	unsigned long flags;
>> -	unsigned int ret = 0;
>> +	unsigned int ret = work_pending(work) ? WORK_BUSY_PENDING : 0;
>
> I'd prefer this as a if() statement.
>
>>   	if (!pool)
>> -		return 0;
>> +		return ret;
>
> I'm a bit confused.  When can we be pending w/o pool?
>

grab the pending bits <==time==> really queued
			^
		this patch considers the work is busy in this time


  reply	other threads:[~2013-02-05 12:07 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-31 18:41 [PATCH 00/13] workqueue: enhance locking and record global worker id for work data Lai Jiangshan
2013-01-31 18:41 ` [PATCH 01/13] workqueue: remove WORK_CPU_NONE Lai Jiangshan
2013-02-04 19:49   ` Tejun Heo
2013-02-05 12:03     ` Lai Jiangshan
2013-02-06 22:34   ` [PATCH wq/for-3.9] workqueue: replace WORK_CPU_NONE/LAST with WORK_CPU_END Tejun Heo
2013-01-31 18:41 ` [PATCH 02/13] workqueue: fix work_busy() Lai Jiangshan
2013-02-04 19:54   ` Tejun Heo
2013-02-05 12:06     ` Lai Jiangshan [this message]
2013-02-05 18:53       ` Tejun Heo
2013-02-06 11:42         ` Lai Jiangshan
2013-02-06 14:05           ` Tejun Heo
2013-02-06 23:02   ` [PATCH wq/for-3.9] workqueue: make work_busy() test WORK_STRUCT_PENDING first Tejun Heo
2013-01-31 18:41 ` [PATCH 03/13] workqueue: don't set work cwq until we queued it on pool Lai Jiangshan
2013-02-04 21:28   ` Tejun Heo
2013-02-05 15:00     ` Lai Jiangshan
2013-02-05 16:45       ` Tejun Heo
2013-02-06 11:35         ` Lai Jiangshan
2013-02-06 14:18           ` Tejun Heo
2013-02-05 15:06     ` Lai Jiangshan
2013-02-07  0:28   ` [PATCH wq/for-3.9 workqueue]: add delayed_work->wq to simplify reentrancy handling Tejun Heo
2013-01-31 18:41 ` [PATCH 04/13] workqueue: clear cwq when cancel the work Lai Jiangshan
2013-02-07  0:53   ` [PATCH wq/for-3.9] workqueue: make work->data point to pool after try_to_grab_pending() Tejun Heo
2013-01-31 18:41 ` [PATCH 05/13] workqueue: change queued detection and remove *mb()s Lai Jiangshan
2013-02-07  1:52   ` [PATCH wq/for-3.9] workqueue: simplify is-work-item-queued-here test Tejun Heo
2013-02-07  2:03     ` [PATCH wq/for-3.9] workqueue: cosmetic update in try_to_grab_pending() Tejun Heo
2013-01-31 18:41 ` [PATCH 06/13] workqueue: get pool id from work->data directly if it is offq Lai Jiangshan
2013-02-07 20:16   ` [PATCH wq/for-3.9] workqueue: make get_work_pool_id() cheaper Tejun Heo
2013-01-31 18:41 ` [PATCH 07/13] workqueue: get pool from wq/cwq Lai Jiangshan
2013-02-07 21:13   ` [PATCH wq/for-3.9] workqueue: pick cwq instead of pool in __queue_work() Tejun Heo
2013-01-31 18:41 ` [PATCH 08/13] workqueue: add lock_pool_executing_work() Lai Jiangshan
2013-02-04 21:34   ` Tejun Heo
2013-02-05 12:15     ` Lai Jiangshan
2013-02-05 19:09       ` Tejun Heo
2013-01-31 18:41 ` [PATCH 09/13] workqueue: add lock_pool_queued_work() Lai Jiangshan
2013-01-31 18:41 ` [PATCH 10/13] workqueue: add lock_pool_own_work() and remove get_work_pool() Lai Jiangshan
2013-02-04 21:38   ` Tejun Heo
2013-01-31 18:41 ` [PATCH 11/13] workqueue: allow more work_pool id space Lai Jiangshan
2013-01-31 18:41 ` [PATCH 12/13] workqueue: add worker's global worker ID Lai Jiangshan
2013-02-04 21:39   ` Tejun Heo
2013-01-31 18:41 ` [PATCH 13/13] workqueue: record global worker ID instead of pool ID in work->data when off-queue Lai Jiangshan
2013-02-04 21:40   ` Tejun Heo
2013-02-04 22:12   ` Tejun Heo
2013-02-05 15:18     ` Lai Jiangshan
2013-02-07 22:02   ` Tejun Heo
2013-02-13 22:23     ` Tejun Heo
2013-02-04 21:04 ` [PATCH 00/13] workqueue: enhance locking and record global worker id for work data Tejun Heo
2013-02-05 16:19   ` Lai Jiangshan
2013-02-05 16:50     ` Tejun Heo

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