From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 97BAA6B005A for ; Fri, 28 Aug 2009 00:22:29 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n7S4MZHw013252 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Fri, 28 Aug 2009 13:22:35 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id E6BB245DE52 for ; Fri, 28 Aug 2009 13:22:34 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id B405245DE50 for ; Fri, 28 Aug 2009 13:22:34 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 90DBF1DB803F for ; Fri, 28 Aug 2009 13:22:34 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 31B0E1DB803C for ; Fri, 28 Aug 2009 13:22:34 +0900 (JST) Date: Fri, 28 Aug 2009 13:20:15 +0900 From: KAMEZAWA Hiroyuki Subject: [RFC][PATCH 0/5] memcg: reduce lock conetion Message-Id: <20090828132015.10a42e40.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: "linux-mm@kvack.org" Cc: "linux-kernel@vger.kernel.org" , "balbir@linux.vnet.ibm.com" , "nishimura@mxp.nes.nec.co.jp" List-ID: Hi, Recently, memcg's res_counter->lock contention on big server is reported and Balbir wrote a workaround for root memcg. It's good but we need some fix for children, too. This set is for reducing lock conetion of memcg's children cgroup based on mmotm-Aug27. I'm sorry I have only 8cpu machine and can't reproduce very troublesome lock conention. Here is lock_stat of make -j 12 on my 8cpu box, befre-after this patch series. [Before] time make -j 12 (Best time in 3 test) real 2m55.170s user 4m38.351s sys 6m40.694s lock_stat version 0.3 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- class name con-bounces contentions waittime-min waittime-max waittime-total acq-bounces acquisitions holdtime-min holdtime-max holdtime-total ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- &counter->lock: 1793728 1824383 0.90 16599.78 1255869.40 24879507 44909568 0.45 31183.88 19505982.15 -------------- &counter->lock 999561 [] res_counter_charge+0x94/0x140 &counter->lock 824822 [] res_counter_uncharge+0x3c/0xb0 -------------- &counter->lock 835597 [] res_counter_uncharge+0x3c/0xb0 &counter->lock 988786 [] res_counter_charge+0x94/0x140 you can see this by "head" ;) [After] time make -j 12 (Best time in 3 test..but score was very stable.) real 2m52.612s user 4m45.450s sys 6m4.422s &counter->lock: 11159 11406 1.02 30.35 6707.74 1097940 3957860 0.47 17652.17 1534430.74 -------------- &counter->lock 2016 [] res_counter_charge+0x4d/0x110 &counter->lock 9390 [] res_counter_uncharge+0x35/0x90 -------------- &counter->lock 8962 [] res_counter_uncharge+0x35/0x90 &counter->lock 2444 [] res_counter_charge+0x4d/0x110 dcache-lock, zone->lru_lock etc is much heavier than this. I expects good result on big servers. But this patch sereis is a "big change". I (and memcg folks) have to be careful... Thanks, -Kame -- 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