From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752078Ab0CSGVr (ORCPT ); Fri, 19 Mar 2010 02:21:47 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:39482 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751939Ab0CSGVo (ORCPT ); Fri, 19 Mar 2010 02:21:44 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Mel Gorman Subject: Re: [PATCH 02/11] mm,migration: Do not try to migrate unmapped anonymous pages Cc: kosaki.motohiro@jp.fujitsu.com, Minchan Kim , KAMEZAWA Hiroyuki , Andrew Morton , Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <20100318111436.GK12388@csn.ul.ie> References: <20100318094720.872F.A69D9226@jp.fujitsu.com> <20100318111436.GK12388@csn.ul.ie> Message-Id: <20100319152103.876F.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Fri, 19 Mar 2010 15:21:41 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > then, this logic depend on SLAB_DESTROY_BY_RCU, not refcount. > > So, I think we don't need your [1/11] patch. > > > > Am I missing something? > > > > The refcount is still needed. The anon_vma might be valid, but the > refcount is what ensures that the anon_vma is not freed and reused. please please why do we need both mechanism. now cristoph is very busy and I am de fact reviewer of page migration and mempolicy code. I really hope to understand your patch. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id DE66F6B004D for ; Fri, 19 Mar 2010 02:21:49 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o2J6LkiW025032 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Fri, 19 Mar 2010 15:21:46 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id C670845DE55 for ; Fri, 19 Mar 2010 15:21:45 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id A546145DE51 for ; Fri, 19 Mar 2010 15:21:45 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 88CEF1DB803F for ; Fri, 19 Mar 2010 15:21:45 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 3A60B1DB803C for ; Fri, 19 Mar 2010 15:21:42 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 02/11] mm,migration: Do not try to migrate unmapped anonymous pages In-Reply-To: <20100318111436.GK12388@csn.ul.ie> References: <20100318094720.872F.A69D9226@jp.fujitsu.com> <20100318111436.GK12388@csn.ul.ie> Message-Id: <20100319152103.876F.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Fri, 19 Mar 2010 15:21:41 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, Minchan Kim , KAMEZAWA Hiroyuki , Andrew Morton , Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: > > then, this logic depend on SLAB_DESTROY_BY_RCU, not refcount. > > So, I think we don't need your [1/11] patch. > > > > Am I missing something? > > > > The refcount is still needed. The anon_vma might be valid, but the > refcount is what ensures that the anon_vma is not freed and reused. please please why do we need both mechanism. now cristoph is very busy and I am de fact reviewer of page migration and mempolicy code. I really hope to understand your patch. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org