From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757114Ab0E0OLl (ORCPT ); Thu, 27 May 2010 10:11:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49649 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756880Ab0E0OLj (ORCPT ); Thu, 27 May 2010 10:11:39 -0400 Message-ID: <4BFE7CFC.4060706@redhat.com> Date: Thu, 27 May 2010 10:09:00 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.4 MIME-Version: 1.0 To: Minchan Kim CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman , Andrea Arcangeli , KAMEZAWA Hiroyuki , Lee Schermerhorn Subject: Re: [PATCH 5/5] extend KSM refcounts to the anon_vma root References: <20100526153819.6e5cec0d@annuminas.surriel.com> <20100526154124.04607d04@annuminas.surriel.com> <20100527140212.GE2112@barrios-desktop> In-Reply-To: <20100527140212.GE2112@barrios-desktop> 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 05/27/2010 10:02 AM, Minchan Kim wrote: > Hmm, I can understand this point. > Now, rmap code always depeneds on root anon_vma's lock. > I think it doesn't depends on KSM and MIGRATION. > > If we don't use KSM and MIGRATION and it is compiled out, > Can root's anon_vma disappear during rmap walking? > who prevent it? > > What am I missing? unlink_anon_vmas walks the list in the order from newest to oldest, ie. the root always gets unlinked (and potentially freed) last. -- All rights reversed