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Date: Mon, 17 Dec 2012 10:52:31 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Michel Lespinasse <walken@google.com>, Hugh Dickins <hughd@google.com>,
        J??rn Engel <joern@logfs.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH v2] mm: Downgrade mmap_sem before locking or populating
 on mmap
Message-ID: <20121217095231.GA1134@gmail.com>
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* Andy Lutomirski <luto@amacapital.net> wrote:

> > 2)
> >
> > More aggressively, we could just make it the _rule_ that the 
> > mm lock gets downgraded to read in mmap_region_helper(), no 
> > matter what.
> >
> > From a quick look I *think* all the usage sites (including 
> > sys_aio_setup()) are fine with that unlocking - but I could 
> > be wrong.
> 
> They are.

Lets try that then - the ugliness of the current patch is 
certainly a problem.

Thanks,

	Ingo