From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B480FC2D0A3 for ; Wed, 4 Nov 2020 08:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E3C722384 for ; Wed, 4 Nov 2020 08:15:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="M560DL4L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728477AbgKDIPt (ORCPT ); Wed, 4 Nov 2020 03:15:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:60474 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726232AbgKDIPt (ORCPT ); Wed, 4 Nov 2020 03:15:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1604477747; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=pu9nDlElO36818d6c492u/kEii7j/MmIxPyMpMKROnw=; b=M560DL4Lx3O469FViCozhx+pg+wAT6bhy87LkS0daF7UpbL2pSwdQb0qgQjOjuaQEY+ZgE QfrD1GZRJV6VZsMjWN1korL9SoGHicDqo0UanIqWyiAOiZ8M7QMbtYKtGE6DjHjLGMueYb fZH8iTV79Qulw6LTGp9j1eM+BKwi4w8= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 2A284ACE0; Wed, 4 Nov 2020 08:15:47 +0000 (UTC) Date: Wed, 4 Nov 2020 09:15:46 +0100 From: Michal Hocko To: Xing Zhengjun Cc: Rong Chen , Waiman Long , Linus Torvalds , Andrew Morton , Shakeel Butt , Chris Down , Johannes Weiner , Roman Gushchin , Tejun Heo , Vladimir Davydov , Yafang Shao , LKML , lkp@lists.01.org, lkp@intel.com, zhengjun.xing@intel.com Subject: Re: [LKP] Re: [mm/memcg] bd0b230fe1: will-it-scale.per_process_ops -22.7% regression Message-ID: <20201104081546.GB10052@dhcp22.suse.cz> References: <20201102091543.GM31092@shao2-debian> <20201102092754.GD22613@dhcp22.suse.cz> <82d73ebb-a31e-4766-35b8-82afa85aa047@intel.com> <20201102100247.GF22613@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 04-11-20 09:20:04, Xing Zhengjun wrote: > > > On 11/2/2020 6:02 PM, Michal Hocko wrote: > > On Mon 02-11-20 17:53:14, Rong Chen wrote: > > > > > > > > > On 11/2/20 5:27 PM, Michal Hocko wrote: > > > > On Mon 02-11-20 17:15:43, kernel test robot wrote: > > > > > Greeting, > > > > > > > > > > FYI, we noticed a -22.7% regression of will-it-scale.per_process_ops due to commit: > > > > > > > > > > > > > > > commit: bd0b230fe14554bfffbae54e19038716f96f5a41 ("mm/memcg: unify swap and memsw page counters") > > > > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > > > I really fail to see how this can be anything else than a data structure > > > > layout change. There is one counter less. > > > > > > > > btw. are cgroups configured at all? What would be the configuration? > > > > > > Hi Michal, > > > > > > We used the default configure of cgroups, not sure what configuration you > > > want, > > > could you give me more details? and here is the cgroup info of will-it-scale > > > process: > > > > > > $ cat /proc/3042/cgroup > > > 12:hugetlb:/ > > > 11:memory:/system.slice/lkp-bootstrap.service > > > > OK, this means that memory controler is enabled and in use. Btw. do you > > get the original performance if you add one phony page_counter after the > > union? > > > I add one phony page_counter after the union and re-test, the regression > reduced to -1.2%. It looks like the regression caused by the data structure > layout change. Thanks for double checking. Could you try to cache align the page_counter struct? If that helps then we should figure which counters acks against each other by adding the alignement between the respective counters. > ========================================================================================= > tbox_group/testcase/rootfs/kconfig/compiler/nr_task/mode/test/cpufreq_governor/ucode/debug-setup: > > lkp-hsw-4ex1/will-it-scale/debian-10.4-x86_64-20200603.cgz/x86_64-rhel-8.3/gcc-9/50%/process/page_fault2/performance/0x16/test1 > > commit: > 8d387a5f172f26ff8c76096d5876b881dec6b7ce > bd0b230fe14554bfffbae54e19038716f96f5a41 > b3233916ab0a883e1117397e28b723bd0e4ac1eb (debug patch add one phony > page_counter after the union) > > 8d387a5f172f26ff bd0b230fe14554bfffbae54e190 b3233916ab0a883e1117397e28b > ---------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev > \ | \ | \ > 187632 -22.8% 144931 -1.2% 185391 > will-it-scale.per_process_ops > 13509525 -22.8% 10435073 -1.2% 13348181 > will-it-scale.workload > > > > -- > Zhengjun Xing -- Michal Hocko SUSE Labs