Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753847Ab2KBXbS (ORCPT ); Fri, 2 Nov 2012 19:31:18 -0400 Received: from mail-ia0-f174.google.com ([209.85.210.174]:50115 "EHLO mail-ia0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776Ab2KBXbQ (ORCPT ); Fri, 2 Nov 2012 19:31:16 -0400 Date: Fri, 2 Nov 2012 16:31:18 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Michal Hocko cc: Andrew Morton , Johannes Weiner , Wen Congyang , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Jiang Liu , bsingharora@gmail.com, KAMEZAWA Hiroyuki , Konstantin Khlebnikov , paul.gortmaker@windriver.com, Tang Chen Subject: Re: [PATCH] memcg: fix hotplugged memory zone oops In-Reply-To: <20121102102159.GA24073@dhcp22.suse.cz> Message-ID: References: <505187D4.7070404@cn.fujitsu.com> <20120913205935.GK1560@cmpxchg.org> <507CF789.6050307@cn.fujitsu.com> <20121018220306.GA1739@cmpxchg.org> <20121102102159.GA24073@dhcp22.suse.cz> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1119 Lines: 34 On Fri, 2 Nov 2012, Michal Hocko wrote: > > OK, it adds "an overhead" also when there is no hotadd going on but this > is just one additional mem access&cmp&je so it shouldn't be noticable > (lruvec->zone is used most of the time later so it not a pointless > load). I think so too. > It is also easier to backport for stable. Yes. > But is there any reason to fix it later properly in the hotadd hook? I don't know. Not everybody liked it fixed this way: it's not unreasonable to see this as a quick hack rather than the right fix. I was expecting objectors to post alternative hotadd hook patches, then we could compare and decide. That didn't happen; but we can certainly look to taking out these lines later if something we agree is better comes along. Not high on anyone's agenda, I think. > > Anyway > Acked-by: Michal Hocko Thanks, Hugh -- 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/