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Message-ID: <7cd5d4b40601041920u596551d2h75e167311e9452e4@mail.gmail.com>
Date: Thu, 5 Jan 2006 11:20:49 +0800
From: jeff shia <tshxiayu@gmail.com>
To: Andrew Morton <akpm@osdl.org>
Subject: Re: what is the state of current after an mm_fault occurs?
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <20060104174808.7b882af8.akpm@osdl.org>
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References: <7cd5d4b40601040240n79b2d654t33424e91059988a9@mail.gmail.com>
	 <20060104174808.7b882af8.akpm@osdl.org>
Sender: linux-kernel-owner@vger.kernel.org
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en,
 You mean in some pagefault place we do schedule()?
  Where?
  Thank you !


On 1/5/06, Andrew Morton <akpm@osdl.org> wrote:
> jeff shia <tshxiayu@gmail.com> wrote:
> >
> >        In my opinion, the state of current should be TASK_RUNNING
> >  after an mm_fault occurs.But I donot know why the function of
> >  handle_mm_fault() set the state of current TASK_RUNNING.
>
> It was a long time ago.. 2.4.early, perhaps.
>
> There was a place (maybe in the select() code) where we were doing
> copy_*_user() while in state TASK_INTERRUPTIBLE.  And iirc there was a
> place in the pagefault code which did schedule().  So we would occasionally
> hit schedule() in state TASK_INTERRUPTIBLE, when we expected to be in state
> TASK_RUNNING.
>
> So we made handle_mm_fault() set TASK_RUNNING to prevent any further such
> things.
>
>
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