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=-0.8 required=3.0 tests=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 7F463C35666 for ; Sat, 22 Feb 2020 17:08:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A0C5206ED for ; Sat, 22 Feb 2020 17:08:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726730AbgBVRIX convert rfc822-to-8bit (ORCPT ); Sat, 22 Feb 2020 12:08:23 -0500 Received: from mga09.intel.com ([134.134.136.24]:39051 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726329AbgBVRIW (ORCPT ); Sat, 22 Feb 2020 12:08:22 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Feb 2020 09:08:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,472,1574150400"; d="scan'208";a="229477357" Received: from orsmsx107.amr.corp.intel.com ([10.22.240.5]) by fmsmga007.fm.intel.com with ESMTP; 22 Feb 2020 09:08:21 -0800 Received: from orsmsx116.amr.corp.intel.com (10.22.240.14) by ORSMSX107.amr.corp.intel.com (10.22.240.5) with Microsoft SMTP Server (TLS) id 14.3.439.0; Sat, 22 Feb 2020 09:08:21 -0800 Received: from orsmsx110.amr.corp.intel.com ([169.254.10.107]) by ORSMSX116.amr.corp.intel.com ([169.254.7.180]) with mapi id 14.03.0439.000; Sat, 22 Feb 2020 09:08:21 -0800 From: "Kleen, Andi" To: "Tang, Feng" CC: Peter Zijlstra , "Chen, Rong A" , Jiri Olsa , Ingo Molnar , Vince Weaver , Jiri Olsa , Alexander Shishkin , Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo , Linus Torvalds , "Naveen N. Rao" , Ravi Bangoria , Stephane Eranian , Thomas Gleixner , LKML , "lkp@lists.01.org" , "Huang, Ying" Subject: RE: [LKP] Re: [perf/x86] 81ec3f3c4c: will-it-scale.per_process_ops -5.5% regression Thread-Topic: [LKP] Re: [perf/x86] 81ec3f3c4c: will-it-scale.per_process_ops -5.5% regression Thread-Index: AQHV6X3LhetjX3VofUmXB9MXuNVibagnce9U Date: Sat, 22 Feb 2020 17:08:20 +0000 Message-ID: References: <20200205123216.GO12867@shao2-debian> <20200205125804.GM14879@hirez.programming.kicks-ass.net> <20200221080325.GA67807@shbuild999.sh.intel.com> ,<20200222124359.GA86836@shbuild999.sh.intel.com> In-Reply-To: <20200222124359.GA86836@shbuild999.sh.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.3.86.139] 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 >Thanks for the suggestion, I tried this and the 5.5 regrssion is gone! >which also confirms the offset for the bulk of stuff following "pmu" >causes the performance drop. Okay that confirms that it is false sharing. Looking at c2c is the right way to go then. Peter, could adopt the padding as a workaround for now? -Andi