From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754662Ab0DZXF2 (ORCPT ); Mon, 26 Apr 2010 19:05:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55144 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751471Ab0DZXF0 (ORCPT ); Mon, 26 Apr 2010 19:05:26 -0400 Date: Tue, 27 Apr 2010 01:04:12 +0200 From: Andrea Arcangeli To: Mel Gorman Cc: Linux-MM , LKML , Minchan Kim , KAMEZAWA Hiroyuki , Christoph Lameter , Rik van Riel , Andrew Morton Subject: Re: [PATCH 0/2] Fix migration races in rmap_walk() Message-ID: <20100426230412.GL8860@random.random> References: <1272321478-28481-1-git-send-email-mel@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1272321478-28481-1-git-send-email-mel@csn.ul.ie> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 26, 2010 at 11:37:56PM +0100, Mel Gorman wrote: > The other issues raised about expand_downwards will need to be re-examined to > see if they still exist and transparent hugepage support will need further > thinking to see if split_huge_page() can deal with these situations. So patch 1 is for aa.git too, and patch 2 is only for mainline with the new anon-vma changes (patch 2 not needed in current aa.git, and if I apply it, it'll deadlock so...) right? split_huge_page is somewhat simpler and more strict in its checking than migrate.c in this respect, and yes patch 2 will also need to be extended to cover split_huge_page the moment I stop backing out the new anon-vma code (but it won't be any different, whatever works for migrate will also work for split_huge_page later). For now I'm much more interested in patch 1 and I'll leave patch 2 to mainline digestion and check it later hope to find all issues fixed by the time transparent hugepage gets merged. About patch 1 it's very interesting because I looked at the race against fork and migrate yesterday and I didn't see issues but I'm going to read your patch 1 in detail now to understand what is the problem you're fixing. Good you posted this fast, so I can try to help ;) Andrea