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Date: Wed, 4 May 2011 21:26:14 -0700
Message-ID: <BANLkTi=wfr1O0c5CjLfjJastN-RKup0zBQ@mail.gmail.com>
Subject: Re: [PATCH] mm: fix possible cause of a page_mapped BUG
From: Michel Lespinasse <walken@google.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: =?UTF-8?B?Um9iZXJ0IMWad2nEmWNraQ==?= <robert@swiecki.net>,
        Hugh Dickins <hughd@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Miklos Szeredi <miklos@szeredi.hu>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Rik van Riel <riel@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1153
Lines: 32

On Wed, May 4, 2011 at 8:37 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> I seriously considered making that "skip stack guard page" and the
> "mlock lookup" be two separate bits, because conceptually they are
> really pretty independent, but right now the only _users_ seem to be
> tied together, so I kept it as one single bit (FOLL_MLOCK).

Yes, this seems best for now.

> But as far as I can tell, the attached patch is 100% equivalent to
> what we do now, except for that "skip stack guard pages only for
> mlock" change.
>
> Comments? I like this patch because it seems to make the logic more
> straightforward.
>
> But somebody else should double-check my logic.

It makes perfect sense.

Reviewed-by: Michel Lespinasse <walken@google.com>

(I would argue for it to go to stable trees as well)

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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