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 03/13] workqueue: don't set work cwq until we queued it on pool
Date: Wed, 6 Feb 2013 19:35:24 +0800 [thread overview]
Message-ID: <CACvQF52FTPEdMTOK29EM2kbxX8KCT3xTyZe1YJG3oe4RAiUk_g@mail.gmail.com> (raw)
In-Reply-To: <20130205164520.GA4276@mtj.dyndns.org>
On Wed, Feb 6, 2013 at 12:45 AM, Tejun Heo <tj@kernel.org> wrote:
> Hey, Lai.
>
> On Tue, Feb 05, 2013 at 11:00:42PM +0800, Lai Jiangshan wrote:
>> The @cpu can be WORK_CPU_UNBOUND, and the current code will delay
>> to determine on which cpu should this work be queued until timeout,
>> I didn't want to change this behavior when I wrote the patch.
>
> Hmmm? The current code determines the CPU on queue_delayed_work().
>
> /*
> * If we cannot get the last pool from @work directly,
> * select the last CPU such that it avoids unnecessarily
> * triggering non-reentrancy check in __queue_work().
> */
> lcpu = cpu;
> if (pool)
> lcpu = pool->cpu;
> if (lcpu == WORK_CPU_UNBOUND)
> lcpu = raw_smp_processor_id();
>
> @lcpu is never WORK_CPU_UNBOUND for bound workqueues and for unbound
> workqueues we of course have cwq for WORK_CPU_UNBOUND.
Are you sure?
@lcpu is only used when it tries to set cwq to work data without
breaking nrt logic.
void delayed_work_timer_fn(unsigned long __data)
{
struct delayed_work *dwork = (struct delayed_work *)__data;
struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work);
/* should have been called from irqsafe timer with irq already off */
__queue_work(dwork->cpu, cwq->wq, &dwork->work);
}
>
>> PS, again, @cpu and @wq can be saved/encoded in dwork.work.entry if needed.
>
> If possible, I'd much prefer to keep it inside delayed_work() proper.
>
> Thanks.
>
> --
> tejun
next prev parent reply other threads:[~2013-02-06 11:35 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
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 [this message]
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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