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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 4DD41C28CC0 for ; Thu, 30 May 2019 13:32:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 190EE259B4 for ; Thu, 30 May 2019 13:32:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727178AbfE3NcB (ORCPT ); Thu, 30 May 2019 09:32:01 -0400 Received: from mga14.intel.com ([192.55.52.115]:47737 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726253AbfE3NcB (ORCPT ); Thu, 30 May 2019 09:32:01 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 May 2019 06:32:00 -0700 X-ExtLoop1: 1 Received: from shao2-debian.sh.intel.com (HELO localhost) ([10.239.13.6]) by orsmga001.jf.intel.com with ESMTP; 30 May 2019 06:31:58 -0700 Date: Thu, 30 May 2019 21:32:15 +0800 From: kernel test robot To: dsterba@suse.cz, Johannes Thumshirn , lkp@01.org, Linus Torvalds , Nikolay Borisov , WenRuo Qu , LKML Subject: Re: [btrfs] 2996e1f8bc: aim7.jobs-per-min -13.2% regression Message-ID: <20190530133215.GC22325@shao2-debian> References: <20190527091719.GS19312@shao2-debian> <20190527114914.GG15290@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190527114914.GG15290@suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 27, 2019 at 01:49:14PM +0200, David Sterba wrote: > On Mon, May 27, 2019 at 05:17:19PM +0800, kernel test robot wrote: > > Greeting, > > > > FYI, we noticed a -13.2% regression of aim7.jobs-per-min due to commit: > > That's interesting and worth an investigation. This should not happen, > the code is almost the same, moved from one function to another and the > call is direct. I'd suspect some low-level causes like cache effects or > branching, the perf-stats.i.* show some differences. > > Other stats say (slabinfo.*extent_buffer) that there was less work over > the period. The slab object counter says that the object reuse was > higher in the bad case. > > And there are many stats that show two digit difference, I'm trying to > make some sense of that, eg. if memory placement on NUMA nodes can > affect the speed of checksumming (changed by the patch) > > So I wonder how reliable the test is and if it really does the same > thing in both cases or if there's some subtle change in the patch that > we've missed. Hi, The test is unstable, we can't reproduce the issue. It's probably a false positive, sorry for the inconvenience. Best Regards, Rong Chen From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============0534989253322398370==" MIME-Version: 1.0 From: kernel test robot To: lkp@lists.01.org Subject: Re: [btrfs] 2996e1f8bc: aim7.jobs-per-min -13.2% regression Date: Thu, 30 May 2019 21:32:15 +0800 Message-ID: <20190530133215.GC22325@shao2-debian> In-Reply-To: <20190527114914.GG15290@suse.cz> List-Id: --===============0534989253322398370== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On Mon, May 27, 2019 at 01:49:14PM +0200, David Sterba wrote: > On Mon, May 27, 2019 at 05:17:19PM +0800, kernel test robot wrote: > > Greeting, > > = > > FYI, we noticed a -13.2% regression of aim7.jobs-per-min due to commit: > = > That's interesting and worth an investigation. This should not happen, > the code is almost the same, moved from one function to another and the > call is direct. I'd suspect some low-level causes like cache effects or > branching, the perf-stats.i.* show some differences. > = > Other stats say (slabinfo.*extent_buffer) that there was less work over > the period. The slab object counter says that the object reuse was > higher in the bad case. > = > And there are many stats that show two digit difference, I'm trying to > make some sense of that, eg. if memory placement on NUMA nodes can > affect the speed of checksumming (changed by the patch) > = > So I wonder how reliable the test is and if it really does the same > thing in both cases or if there's some subtle change in the patch that > we've missed. Hi, The test is unstable, we can't reproduce the issue. It's probably a false positive, sorry for the inconvenience. Best Regards, Rong Chen --===============0534989253322398370==--