From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752642Ab0ECRLY (ORCPT ); Mon, 3 May 2010 13:11:24 -0400 Received: from casper.infradead.org ([85.118.1.10]:54338 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166Ab0ECRLW (ORCPT ); Mon, 3 May 2010 13:11:22 -0400 Subject: Re: [PATCH 1/2] mm: Take all anon_vma locks in anon_vma_lock From: Peter Zijlstra To: Andrea Arcangeli Cc: Rik van Riel , akpm@linux-foundation.org, torvalds@linux-foundation.org, Mel Gorman , Linux-MM , LKML , Minchan Kim , KAMEZAWA Hiroyuki , Christoph Lameter In-Reply-To: <20100503170230.GF19891@random.random> References: <20100503121743.653e5ecc@annuminas.surriel.com> <20100503121847.7997d280@annuminas.surriel.com> <1272905712.1642.150.camel@laptop> <20100503170230.GF19891@random.random> Content-Type: text/plain; charset="UTF-8" Date: Mon, 03 May 2010 19:11:19 +0200 Message-ID: <1272906679.1642.152.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2010-05-03 at 19:02 +0200, Andrea Arcangeli wrote: > On Mon, May 03, 2010 at 06:55:12PM +0200, Peter Zijlstra wrote: > > This does leave me worrying about concurrent faults poking at > > vma->vm_end without synchronization. > > I didn't check this patch in detail yet. I agree it can be removed and > I think it can be safely replaced with the page_table_lock. Sure, it could probably be replaced with the ptl, but a single anon_vma->lock would I think be better since there's more of them.