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From: Tejun Heo <tj@kernel.org>
To: Deepawali Verma <dverma249@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Work queue questions
Date: Fri, 21 Sep 2012 12:27:20 -0700	[thread overview]
Message-ID: <20120921192720.GJ7264@google.com> (raw)
In-Reply-To: <CAHCeSFpa28d-7ruMKSw6z2EYKYN-5udVouUJOi4cnj4dPad-TA@mail.gmail.com>

On Fri, Sep 21, 2012 at 08:26:01PM +0100, Deepawali Verma wrote:
>      kworker/u:1-21    [000]   110.964895: task_event: MYTASKJOB2381 XStarted
>      kworker/u:1-21    [000]   110.964909: task_event: MYTASKJOB2381 Xstopped
>      kworker/u:1-21    [000]   110.965137: task_event: MYTASKJOB2382 XStarted
>      kworker/u:1-21    [000]   110.965154: task_event: MYTASKJOB2382 Xstopped
>      kworker/u:5-3724  [000]   110.965311: task_event: MYTASKJOB2383 XStarted
>      kworker/u:5-3724  [000]   110.965325: task_event: MYTASKJOB2383 Xstopped
> 
> I have this one big task to whom I divided into small sub tasks. These
> are numbered 2381, 2382 and 2383, what was I expecting that task 2381,
> 2382, 2383 run in parallel. I have put start and stop markers here so
> that I can see how this concurrency managed work queue is distributing
> the load.
> 
> I found that task no 2381 is started first and exited before starting
> task 2382 and so on. What I expected that it should start the three
> sub tasks in parallel, not one by one.
> 
> Where is concurrency here?

If none of them blocks, there isn't much point in throwing more
threads at them.  What are those thread doing?

Thanks.

-- 
tejun

  reply	other threads:[~2012-09-21 19:27 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-21 17:35 Work queue questions Dinky Verma
2012-09-21 17:49 ` Tejun Heo
2012-09-21 18:30   ` Deepawali Verma
2012-09-21 18:35     ` Tejun Heo
2012-09-21 19:26       ` Deepawali Verma
2012-09-21 19:27         ` Tejun Heo [this message]
2012-09-21 19:35           ` Deepawali Verma
2012-09-21 19:40             ` Tejun Heo
2012-09-22  4:24             ` anish singh
2012-09-22  5:27               ` Daniel Taylor
2012-09-22  6:05                 ` anish singh
2012-09-22  6:12                   ` Tejun Heo
2012-09-22  6:18                   ` Daniel Taylor
2012-09-24  7:25                     ` Deepawali Verma
     [not found]                       ` <CAK-9PRB7KvPNgcsXiNG08-7OdrkkNc2ushusXh9rVm93J0xcHA@mail.gmail.com>
     [not found]                         ` <CAHCeSFqmeOkKySxMUXgtnev+HL-NC6MdmeuDYONymYaNczb7RA@mail.gmail.com>
2012-09-24 16:56                           ` Deepawali Verma
2012-09-24 18:10                             ` Tejun Heo
2012-09-24 19:57                               ` Deepawali Verma
2012-09-24 20:08                                 ` Tejun Heo
2012-09-24 20:52                                   ` Deepawali Verma
2012-09-24 20:54                                     ` Tejun Heo
2012-09-25  3:05                                   ` anish singh
2012-09-24 17:07                           ` Chinmay V S

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