From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755130Ab3JGOCJ (ORCPT ); Mon, 7 Oct 2013 10:02:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6821 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751734Ab3JGOCE (ORCPT ); Mon, 7 Oct 2013 10:02:04 -0400 Message-ID: <5252BECA.4080302@redhat.com> Date: Mon, 07 Oct 2013 10:01:46 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Mel Gorman CC: Peter Zijlstra , Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML Subject: Re: [PATCH 06/63] mm: Prevent parallel splits during THP migration References: <1381141781-10992-1-git-send-email-mgorman@suse.de> <1381141781-10992-7-git-send-email-mgorman@suse.de> In-Reply-To: <1381141781-10992-7-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/2013 06:28 AM, Mel Gorman wrote: > THP migrations are serialised by the page lock but on its own that does > not prevent THP splits. If the page is split during THP migration then > the pmd_same checks will prevent page table corruption but the unlock page > and other fix-ups potentially will cause corruption. This patch takes the > anon_vma lock to prevent parallel splits during migration. > > Cc: stable > Signed-off-by: Mel Gorman Acked-by: Rik van Riel -- All rights reversed