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Date: Wed, 24 Sep 2008 09:20:40 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: sqazi@google.com (Salman Qazi), linux-mm@kvack.org,
       linux-kernel@vger.kernel.org
Subject: Re: mlock: Make the mlock system call interruptible by fatal
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On Wed, 24 Sep 2008 11:22:55 +0100 Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

> > > Can we do
> > >
> > >        return i ? i : -EINTR;
> > >
> > > in the usual fashion?
> > 
> > Fixed.
> 
> If its only interruptible by fatal signals why do we care what the return
> is ?
> 

For the immediate in-kernel caller.  __get_user_pages() took a ref on a
few pages which the caller needs to undo before doing anything else
(like processing the signal).