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 AB3A5C433DF for ; Wed, 19 Aug 2020 02:23:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E2D52075E for ; Wed, 19 Aug 2020 02:23:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726799AbgHSCXT convert rfc822-to-8bit (ORCPT ); Tue, 18 Aug 2020 22:23:19 -0400 Received: from mga12.intel.com ([192.55.52.136]:43403 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726372AbgHSCXT (ORCPT ); Tue, 18 Aug 2020 22:23:19 -0400 IronPort-SDR: EpOzc/kNh3XgmpzDyhAcBAHxyHh/eYcHdyDfcrA2bYNVap+1v6Fi6WkPhxNrhUa0WGLeeU1bT/ tmAVl5kfWxgQ== X-IronPort-AV: E=McAfee;i="6000,8403,9717"; a="134554113" X-IronPort-AV: E=Sophos;i="5.76,329,1592895600"; d="scan'208";a="134554113" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2020 19:23:17 -0700 IronPort-SDR: haqcwgHPC5gRqDZZDGhSw9qb951yOxhfJKXto90QBLzLwbxrTfzcbGyyHE6/cjOdR23FvFSwET T1XtYwz48WDQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,329,1592895600"; d="scan'208";a="497068264" Received: from fmsmsx603-2.cps.intel.com (HELO fmsmsx603.amr.corp.intel.com) ([10.18.84.213]) by fmsmga006.fm.intel.com with ESMTP; 18 Aug 2020 19:23:16 -0700 Received: from shsmsx602.ccr.corp.intel.com (10.109.6.142) by fmsmsx603.amr.corp.intel.com (10.18.126.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Tue, 18 Aug 2020 19:23:15 -0700 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by SHSMSX602.ccr.corp.intel.com (10.109.6.142) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 19 Aug 2020 10:23:12 +0800 Received: from fmsmsx610.amr.corp.intel.com ([10.18.126.90]) by fmsmsx610.amr.corp.intel.com ([10.18.126.90]) with mapi id 15.01.1713.004; Tue, 18 Aug 2020 19:23:11 -0700 From: "Luck, Tony" To: "Tang, Feng" CC: Borislav Petkov , "Chen, Rong A" , LKML , "lkp@lists.01.org" Subject: RE: [LKP] Re: [x86/mce] 1de08dccd3: will-it-scale.per_process_ops -14.1% regression Thread-Topic: [LKP] Re: [x86/mce] 1de08dccd3: will-it-scale.per_process_ops -14.1% regression Thread-Index: AQHWdTm7eFqn4vHQO0+vfjZnMLG+/6k+S8yAgADZR4D//46QUA== Date: Wed, 19 Aug 2020 02:23:11 +0000 Message-ID: <149e0cfb5b7e48dfb9bea966c7741336@intel.com> References: <20200425114414.GU26573@shao2-debian> <20200425130136.GA28245@zn.tnic> <20200818082943.GA65567@shbuild999.sh.intel.com> <20200818200654.GA21494@agluck-desk2.amr.corp.intel.com> <20200819020437.GA2605@shbuild999.sh.intel.com> In-Reply-To: <20200819020437.GA2605@shbuild999.sh.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-reaction: no-action dlp-version: 11.5.1.3 x-originating-ip: [10.1.200.100] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 0000000000019260 D pqr_state Do you have /sys/fs/resctrl mounted? This variable is read on every context switch. If your benchmark does a lot of context switching and this now shares a cache line with something different (especially something that is sometimes modified from another CPU) that could cause some cache line bouncing. -Tony