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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 C8A6DC433EF for ; Mon, 6 Sep 2021 06:09:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 85FEB60E94 for ; Mon, 6 Sep 2021 06:09:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 85FEB60E94 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id E5E546B0071; Mon, 6 Sep 2021 02:09:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E0E866B0072; Mon, 6 Sep 2021 02:09:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CFD9E900002; Mon, 6 Sep 2021 02:09:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0070.hostedemail.com [216.40.44.70]) by kanga.kvack.org (Postfix) with ESMTP id C018A6B0071 for ; Mon, 6 Sep 2021 02:09:25 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 6F293181AF5EA for ; Mon, 6 Sep 2021 06:09:25 +0000 (UTC) X-FDA: 78556121490.06.5896A8D Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by imf15.hostedemail.com (Postfix) with ESMTP id CD7D7D00009D for ; Mon, 6 Sep 2021 06:09:24 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10098"; a="199422836" X-IronPort-AV: E=Sophos;i="5.85,271,1624345200"; d="scan'208";a="199422836" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Sep 2021 23:09:22 -0700 X-IronPort-AV: E=Sophos;i="5.85,271,1624345200"; d="scan'208";a="536498601" Received: from jzhan31-mobl1.ccr.corp.intel.com (HELO chenyu5-mobl1) ([10.249.173.11]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Sep 2021 23:09:13 -0700 Date: Mon, 6 Sep 2021 14:09:08 +0800 From: Chen Yu To: "Huang, Ying" Cc: Dave Hansen , kernel test robot , Rui Zhang , Len Brown , "Rafael J. Wysocki" , Andrew Morton , 0day robot , Yang Shi , Zi Yan , Michal Hocko , Wei Xu , Oscar Salvador , David Rientjes , Dan Williams , David Hildenbrand , Greg Thelen , Keith Busch , Yang Shi , LKML , lkp@lists.01.org, feng.tang@intel.com, zhengjun.xing@linux.intel.com, dave.hansen@linux.intel.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: Re: [mm/migrate] 9eeb73028c: stress-ng.memhotplug.ops_per_sec -53.8% regression Message-ID: <20210906060908.GA17483@chenyu5-mobl1> References: <20210905135932.GE15026@xsang-OptiPlex-9020> <87y28aii58.fsf@yhuang6-desk2.ccr.corp.intel.com> <87lf4ai6u3.fsf@yhuang6-desk2.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87lf4ai6u3.fsf@yhuang6-desk2.ccr.corp.intel.com> Authentication-Results: imf15.hostedemail.com; dkim=none; spf=none (imf15.hostedemail.com: domain of yu.c.chen@intel.com has no SPF policy when checking 192.55.52.136) smtp.mailfrom=yu.c.chen@intel.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none) X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: CD7D7D00009D X-Stat-Signature: k85q5txfe6xkome51ruamcxwsfsdgf79 X-HE-Tag: 1630908564-936111 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Sep 06, 2021 at 01:57:56PM +0800, Huang, Ying wrote: > Dave Hansen writes: > > > On 9/5/21 6:53 PM, Huang, Ying wrote: > >>> in testcase: stress-ng > >>> on test machine: 96 threads 2 sockets Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 192G memory > >>> with following parameters: > >>> > >>> nr_threads: 10% > >>> disk: 1HDD > >>> testtime: 60s > >>> fs: ext4 > >>> class: os > >>> test: memhotplug > >>> cpufreq_governor: performance > >>> ucode: 0x5003006 > >>> > >> Because we added some operations during online/offline CPU, it's > >> expected that the performance of online/offline CPU will decrease. In > >> most cases, the performance of CPU hotplug isn't a big problem. But > >> then I remembers that the performance of the CPU hotplug may influence > >> suspend/resume performance :-( > >> > >> It appears that it is easy and reasonable to enclose the added > >> operations inside #ifdef CONFIG_NUMA. Is this sufficient to restore the > >> performance of suspend/resume? > > > > It's "memhotplug", not CPUs, right? > > Yes. Thanks for pointing that out! > > We will update node_demotion[] in CPU hotplug too. Because the status > that whether a node has CPU may change after CPU hotplug. And CPU > online/offline performance may be relevant for suspend/resume. > Rui and I took a look at the default kernel config, it seems that CONFIG_NUMA is enabled on laptops on some distributions. Maybe a runtime detecting flag indicating that whether this system has enabled NUMA (static key eg) would be an option too, so as not to enable node_demotion[] on non-NUMA laptops/desktops. thanks, Chenyu