From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756051Ab2GaSXg (ORCPT ); Tue, 31 Jul 2012 14:23:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14106 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623Ab2GaSXe (ORCPT ); Tue, 31 Jul 2012 14:23:34 -0400 Message-ID: <50181E0D.4090706@redhat.com> Date: Tue, 31 Jul 2012 14:03:57 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Mel Gorman CC: Larry Woodman , Hugh Dickins , Michal Hocko , Linux-MM , David Gibson , Ken Chen , Cong Wang , LKML Subject: Re: [PATCH -alternative] mm: hugetlbfs: Close race during teardown of hugetlbfs shared page tables V2 (resend) References: <20120720134937.GG9222@suse.de> <20120720141108.GH9222@suse.de> <20120720143635.GE12434@tiehlicka.suse.cz> <20120720145121.GJ9222@suse.de> <50118E7F.8000609@redhat.com> <50120FA8.20409@redhat.com> <20120727102356.GD612@suse.de> <5016DC5F.7030604@redhat.com> <20120731124650.GO612@suse.de> In-Reply-To: <20120731124650.GO612@suse.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/31/2012 08:46 AM, Mel Gorman wrote: > mm: hugetlbfs: Correctly detect if page tables have just been shared > > Each page mapped in a processes address space must be correctly > accounted for in _mapcount. Normally the rules for this are > straight-forward but hugetlbfs page table sharing is different. > The page table pages at the PMD level are reference counted while > the mapcount remains the same. If this accounting is wrong, it causes > bugs like this one reported by Larry Woodman > Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel -- All rights reversed