Date: Tue, 17 Aug 2010 16:21:44 +0200
From: Andi Kleen <andi@firstfloor.org>
To: Jeff Moyer <jmoyer@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
        Christoph Lameter <cl@linux-foundation.org>,
        Andi Kleen <andi@firstfloor.org>,
        Andrew Morton <akpm@linux-foundation.org>, Mel Gorman <mel@csn.ul.ie>,
        Wu Fengguang <fengguang.wu@intel.com>,
        "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>,
        linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
        Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [RFC] [PATCH 2/4] dio: add page locking for direct I/O
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On Tue, Aug 17, 2010 at 09:46:56AM -0400, Jeff Moyer wrote:
> Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> writes:
> 
> > BTW, from the discussion with Christoph I noticed my misunderstanding
> > about the necessity of additional page locking. It would seem that
> > without page locking there is no danger of racing between direct I/O and
> > page migration. So I retract this additional locking patch-set.
> 
> OK, great!  ;-)

Well it sounds like we still may need something. It isn't good if O_DIRECT
can starve (or DoS) migration.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.
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