From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id A77636B004D for ; Wed, 9 Sep 2009 16:31:04 -0400 (EDT) Received: from d23relay02.au.ibm.com (d23relay02.au.ibm.com [202.81.31.244]) by e23smtp04.au.ibm.com (8.14.3/8.13.1) with ESMTP id n89KSCQx017057 for ; Thu, 10 Sep 2009 06:28:12 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay02.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n89KV1lw1204458 for ; Thu, 10 Sep 2009 06:31:01 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n89KV1Qx015654 for ; Thu, 10 Sep 2009 06:31:01 +1000 Date: Thu, 10 Sep 2009 02:00:42 +0530 From: Balbir Singh Subject: Re: [RFC][PATCH 0/4][mmotm] memcg: reduce lock contention v3 Message-ID: <20090909203042.GA4473@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20090909173903.afc86d85.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090909173903.afc86d85.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "nishimura@mxp.nes.nec.co.jp" List-ID: * KAMEZAWA Hiroyuki [2009-09-09 17:39:03]: > This patch series is for reducing memcg's lock contention on res_counter, v3. > (sending today just for reporting current status in my stack.) > > It's reported that memcg's res_counter can cause heavy false sharing / lock > conention and scalability is not good. This is for relaxing that. > No terrible bugs are found, I'll maintain/update this until the end of next > merge window. Tests on big-smp and new-good-idea are welcome. > > This patch is on to mmotm+Nishimura's fix + Hugh's get_user_pages() patch. > But can be applied directly against mmotm, I think. > > numbers: > > I used 8cpu x86-64 box and run make -j 12 kernel. > Before make, make clean and drop_caches. > Kamezawa-San I was able to test on a 24 way using my parallel page fault test program and here is what I see Performance counter stats for '/home/balbir/parallel_pagefault' (3 runs): 7191673.834385 task-clock-msecs # 23.953 CPUs ( +- 0.001% ) 427765 context-switches # 0.000 M/sec ( +- 0.106% ) 234 CPU-migrations # 0.000 M/sec ( +- 20.851% ) 87975343 page-faults # 0.012 M/sec ( +- 0.347% ) 5962193345280 cycles # 829.041 M/sec ( +- 0.012% ) 1009132401195 instructions # 0.169 IPC ( +- 0.059% ) 10068652670 cache-references # 1.400 M/sec ( +- 2.581% ) 2053688394 cache-misses # 0.286 M/sec ( +- 0.481% ) 300.238748326 seconds time elapsed ( +- 0.001% ) Without the patch I saw Performance counter stats for '/home/balbir/parallel_pagefault' (3 runs): 7198364.596593 task-clock-msecs # 23.959 CPUs ( +- 0.004% ) 425104 context-switches # 0.000 M/sec ( +- 0.244% ) 157 CPU-migrations # 0.000 M/sec ( +- 13.291% ) 28964117 page-faults # 0.004 M/sec ( +- 0.106% ) 5786854402292 cycles # 803.912 M/sec ( +- 0.013% ) 835828892399 instructions # 0.144 IPC ( +- 0.073% ) 6240606753 cache-references # 0.867 M/sec ( +- 1.058% ) 2068445332 cache-misses # 0.287 M/sec ( +- 1.844% ) 300.443366784 seconds time elapsed ( +- 0.005% ) This does look like a very good improvement. -- Balbir -- 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