From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754112Ab1KXIzk (ORCPT ); Thu, 24 Nov 2011 03:55:40 -0500 Received: from zene.cmpxchg.org ([85.214.230.12]:47850 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752999Ab1KXIzj (ORCPT ); Thu, 24 Nov 2011 03:55:39 -0500 Date: Thu, 24 Nov 2011 09:55:33 +0100 From: Johannes Weiner To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Michal Hocko , Balbir Singh , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch 7/8] mm: memcg: modify PageCgroupAcctLRU non-atomically Message-ID: <20111124085532.GB6843@cmpxchg.org> References: <1322062951-1756-1-git-send-email-hannes@cmpxchg.org> <1322062951-1756-8-git-send-email-hannes@cmpxchg.org> <20111124090915.2f6e2e2c.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111124090915.2f6e2e2c.kamezawa.hiroyu@jp.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 24, 2011 at 09:09:15AM +0900, KAMEZAWA Hiroyuki wrote: > On Wed, 23 Nov 2011 16:42:30 +0100 > Johannes Weiner wrote: > > > From: Johannes Weiner > > > > This bit is protected by zone->lru_lock, there is no need for locked > > operations when setting and clearing it. > > > > Signed-off-by: Johannes Weiner > > This atomic ops are for avoiding race with other ops as lock_page_cgroup(). > Or other Set/ClearPageCgroup.... > > Do I misunderstand atomic ops v.s. non-atomic ops race ? Nope, you are spot-on. I'm the cretin. ;-) See my reply to Hugh's email.