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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 35045C433ED for ; Wed, 28 Apr 2021 06:15:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08CE661418 for ; Wed, 28 Apr 2021 06:15:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236141AbhD1GQF (ORCPT ); Wed, 28 Apr 2021 02:16:05 -0400 Received: from mga05.intel.com ([192.55.52.43]:32847 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229464AbhD1GQE (ORCPT ); Wed, 28 Apr 2021 02:16:04 -0400 IronPort-SDR: 5u0bowKIMwxtTxCfx0zpbsIpfHMafNMpYS3bWE2yUkfsJxIZbyZ3VYtIiPgxiXFylsyv1mm/Go ywDN2cmtPzDA== X-IronPort-AV: E=McAfee;i="6200,9189,9967"; a="282001975" X-IronPort-AV: E=Sophos;i="5.82,257,1613462400"; d="scan'208";a="282001975" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Apr 2021 23:15:19 -0700 IronPort-SDR: GMDDMjgMYoZyzKLyhMFgmpQlQ9mesaOT5JMyWzgX6wplQcfhiV//g5d2WRjtEiBdm8jCByaqeE eHwdAfs2Wl9g== X-IronPort-AV: E=Sophos;i="5.82,257,1613462400"; d="scan'208";a="430145653" Received: from xingzhen-mobl.ccr.corp.intel.com (HELO [10.238.4.46]) ([10.238.4.46]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Apr 2021 23:15:17 -0700 Subject: Re: [LKP] Re: [mm/writeback] e5dbd33218: will-it-scale.per_process_ops -3.8% regression To: Matthew Wilcox , lkp Cc: David Howells , Christoph Hellwig , LKML , lkp@lists.01.org, lkp@intel.com References: <20210423054601.GC13944@xsang-OptiPlex-9020> <20210423124753.GA235567@casper.infradead.org> From: Xing Zhengjun Message-ID: Date: Wed, 28 Apr 2021 14:15:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <20210423124753.GA235567@casper.infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matthew, On 4/23/2021 8:47 PM, Matthew Wilcox wrote: > On Fri, Apr 23, 2021 at 01:46:01PM +0800, kernel test robot wrote: >> FYI, we noticed a -3.8% regression of will-it-scale.per_process_ops due to commit: >> commit: e5dbd33218bd8d87ab69f730ab90aed5fab7eb26 ("mm/writeback: Add wait_on_page_writeback_killable") > That commit just adds a function. It doesn't add any callers. It must > just be moving something around ... The micro benchmark like will-it-scale is sensitive to the alignments (text/data), so I apply the data align debug patch and re-test, the regression reduced to -1.5%. ========================================================================================= tbox_group/testcase/rootfs/kconfig/compiler/nr_task/mode/test/cpufreq_governor/ucode: lkp-csl-2sp9/will-it-scale/debian-10.4-x86_64-20200603.cgz/x86_64-rhel-8.3-ge5dbd33218bd-no-dynamic/gcc-9/16/process/mmap2/performance/0x5003006 commit:   a142a3781e3dc0c03a48688cac619c2684eed18f (fs/cachefiles: Remove wait_bit_key layout dependency)   86460bf788cb360a14811fadb3f94f9765ba5a23 (mm/writeback: Add wait_on_page_writeback_killable) a142a3781e3dc0c0 86460bf788cb360a14811fadb3f ---------------- ---------------------------          %stddev     %change         %stddev              \          |                \    9089952            -1.5%    8953838 will-it-scale.16.processes     568121            -1.5%     559614 will-it-scale.per_process_ops    9089952            -1.5%    8953838        will-it-scale.workload >> 39f985c8f667c80a e5dbd33218bd8d87ab69f730ab9 >> ---------------- --------------------------- >> %stddev %change %stddev >> \ | \ >> 9359770 -3.8% 9001769 will-it-scale.16.processes >> 584985 -3.8% 562610 will-it-scale.per_process_ops >> 9359770 -3.8% 9001769 will-it-scale.workload >> 15996 -1.2% 15811 proc-vmstat.nr_kernel_stack >> 23577 ± 10% +18.5% 27937 ± 7% softirqs.CPU48.SCHED >> 5183 ± 41% +47.2% 7630 ± 7% interrupts.CPU1.NMI:Non-maskable_interrupts >> 5183 ± 41% +47.2% 7630 ± 7% interrupts.CPU1.PMI:Performance_monitoring_interrupts >> 54.33 ± 12% +18.4% 64.33 ± 7% perf-sched.wait_and_delay.count.schedule_hrtimeout_range_clock.poll_schedule_timeout.constprop.0.do_sys_poll >> 153.34 ± 24% -45.9% 83.00 ± 25% perf-sched.wait_and_delay.max.ms.schedule_timeout.rcu_gp_kthread.kthread.ret_from_fork >> 153.33 ± 24% -45.9% 82.99 ± 25% perf-sched.wait_time.max.ms.schedule_timeout.rcu_gp_kthread.kthread.ret_from_fork >> 2.424e+10 -3.8% 2.332e+10 perf-stat.i.branch-instructions >> 0.47 +3.7% 0.48 perf-stat.i.cpi >> 2.529e+10 -4.0% 2.428e+10 perf-stat.i.dTLB-loads >> 1.15e+10 -3.8% 1.106e+10 perf-stat.i.dTLB-stores >> 54249733 -4.8% 51627939 perf-stat.i.iTLB-load-misses >> 1.004e+11 -3.8% 9.661e+10 perf-stat.i.instructions >> 2.15 -3.6% 2.07 perf-stat.i.ipc >> 693.66 -3.9% 666.70 perf-stat.i.metric.M/sec >> 0.46 +3.7% 0.48 perf-stat.overall.cpi >> 2.15 -3.6% 2.08 perf-stat.overall.ipc >> 2.416e+10 -3.8% 2.324e+10 perf-stat.ps.branch-instructions >> 2.52e+10 -4.0% 2.419e+10 perf-stat.ps.dTLB-loads >> 1.146e+10 -3.8% 1.102e+10 perf-stat.ps.dTLB-stores >> 54065825 -4.8% 51454019 perf-stat.ps.iTLB-load-misses >> 1.001e+11 -3.8% 9.628e+10 perf-stat.ps.instructions >> 3.025e+13 -3.9% 2.908e+13 perf-stat.total.instructions >> 0.89 ± 14% -0.1 0.77 ± 11% perf-profile.calltrace.cycles-pp.atime_needs_update.touch_atime.shmem_mmap.mmap_region.do_mmap >> 0.14 ± 13% -0.1 0.04 ± 71% perf-profile.children.cycles-pp.common_mmap >> 0.61 ± 12% -0.1 0.52 ± 12% perf-profile.children.cycles-pp.common_file_perm >> 0.21 ± 8% -0.0 0.17 ± 11% perf-profile.children.cycles-pp.vma_set_page_prot >> 0.12 ± 8% -0.0 0.09 ± 12% perf-profile.children.cycles-pp.blocking_notifier_call_chain >> 0.12 ± 14% -0.0 0.09 ± 15% perf-profile.children.cycles-pp.get_mmap_base >> 0.09 ± 8% -0.0 0.07 ± 11% perf-profile.children.cycles-pp.vm_pgprot_modify >> 0.13 ± 15% +0.1 0.19 ± 8% perf-profile.children.cycles-pp.cap_capable >> 0.03 ±102% +0.1 0.12 ± 12% perf-profile.children.cycles-pp.munmap@plt >> 0.14 ± 13% +0.1 0.24 ± 6% perf-profile.children.cycles-pp.testcase >> 0.33 ± 10% -0.1 0.23 ± 10% perf-profile.self.cycles-pp.cap_vm_enough_memory >> 0.13 ± 11% -0.1 0.03 ±100% perf-profile.self.cycles-pp.common_mmap >> 0.48 ± 12% -0.1 0.41 ± 12% perf-profile.self.cycles-pp.common_file_perm >> 0.49 ± 12% -0.1 0.43 ± 13% perf-profile.self.cycles-pp.vm_area_alloc >> 0.12 ± 8% -0.0 0.09 ± 12% perf-profile.self.cycles-pp.blocking_notifier_call_chain >> 0.12 ± 13% -0.0 0.09 ± 14% perf-profile.self.cycles-pp.get_mmap_base >> 0.11 ± 8% +0.0 0.16 ± 10% perf-profile.self.cycles-pp.__x64_sys_munmap >> 0.11 ± 14% +0.1 0.18 ± 8% perf-profile.self.cycles-pp.cap_capable >> 0.12 ± 11% +0.1 0.20 ± 6% perf-profile.self.cycles-pp.testcase >> 0.01 ±223% +0.1 0.11 ± 13% perf-profile.self.cycles-pp.munmap@plt > I'm struggling to see anything in that that says anything other than > "we did 3-4% less work". Maybe someone else has something useful to > say about it? > _______________________________________________ > LKP mailing list -- lkp@lists.01.org > To unsubscribe send an email to lkp-leave@lists.01.org -- Zhengjun Xing