Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756147Ab0DWHBz (ORCPT ); Fri, 23 Apr 2010 03:01:55 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:45661 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756092Ab0DWHBx (ORCPT ); Fri, 23 Apr 2010 03:01:53 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Fri, 23 Apr 2010 15:57:55 +0900 From: KAMEZAWA Hiroyuki To: balbir@linux.vnet.ibm.com Cc: Li Zefan , Daisuke Nishimura , "Paul E. McKenney" , "linux-mm@kvack.org" , LKML , "akpm@linux-foundation.org" Subject: Re: [BUGFIX][PATCH] memcg rcu lock fix v3 Message-Id: <20100423155755.7a3761fe.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100423070011.GS3994@balbir.in.ibm.com> References: <4BD10D59.9090504@cn.fujitsu.com> <20100423121424.ae47efcb.kamezawa.hiroyu@jp.fujitsu.com> <4BD118E2.7080307@cn.fujitsu.com> <4BD11A24.2070500@cn.fujitsu.com> <20100423125814.01e95bce.kamezawa.hiroyu@jp.fujitsu.com> <20100423130349.f320d0be.kamezawa.hiroyu@jp.fujitsu.com> <20100423070011.GS3994@balbir.in.ibm.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.2 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1539 Lines: 49 On Fri, 23 Apr 2010 12:30:11 +0530 Balbir Singh wrote: > * KAMEZAWA Hiroyuki [2010-04-23 13:03:49]: > > > On Fri, 23 Apr 2010 12:58:14 +0900 > > KAMEZAWA Hiroyuki wrote: > > > > > On Fri, 23 Apr 2010 11:55:16 +0800 > > > Li Zefan wrote: > > > > > > > Li Zefan wrote: > > > > > KAMEZAWA Hiroyuki wrote: > > > > >> On Fri, 23 Apr 2010 11:00:41 +0800 > > > > >> Li Zefan wrote: > > > > >> > > > > >>> with CONFIG_PROVE_RCU=y, I saw this warning, it's because > > > > >>> css_id() is not under rcu_read_lock(). > > > > >>> > > > > >> Ok. Thank you for reporting. > > > > >> This is ok ? > > > > > > > > > > Yes, and I did some more simple tests on memcg, no more warning > > > > > showed up. > > > > > > > > > > > > > oops, after trigging oom, I saw 2 more warnings: > > > > > > > > > > Thank you for good testing. > > v3 here...sorry too rapid posting... > > > > Looking at the patch we seem to be protecting the use of only css_*(). > I wonder if we should push down the rcu_read_*lock() semnatics to the > css routines or is it just too instrusive to do it that way? > Maybe worth to consider for future patches for clean up. Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/