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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 125CDC433B4 for ; Thu, 22 Apr 2021 16:24:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDEFD61405 for ; Thu, 22 Apr 2021 16:24:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236414AbhDVQZE (ORCPT ); Thu, 22 Apr 2021 12:25:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232670AbhDVQZD (ORCPT ); Thu, 22 Apr 2021 12:25:03 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 599B1C06174A for ; Thu, 22 Apr 2021 09:24:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=IK2DRL9QTskPdmvchMK2QQZwls+b8mo8keCxH1wBohQ=; b=mJGAf+N7muFsXFIRyvjbKiERu5 b6L1zKXmvmeJsmZyBZEJBMZi0Euz7eFDl7KEHHnpSu71+u/6/d1dLBOXZ+brOgN+QlJiVfZwcTedI rc3IyAmT4NLjaMn+xsdZa69smJ1SLjcdYQI6BAPkRBtQrqhqezzQwLHCHCE2rQRO+UeDGXtumFBop Idt7PMJvu2skdNlIG0j88ngqk6YEdu1VmcXlxsBBG54HEfvmtLEmf49nMkZrTng+o4Qc1YKOeTRk+ pHe/txF437gin6ojUYKeDUEMGFsZ3j4oKlmqtyfbhS+AJWOmvj2my2RJNWtwKtUY2zEjBcDcoHLYx Nli0QjtA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lZc7j-00H3aM-1M; Thu, 22 Apr 2021 16:24:15 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 061A53001E2; Thu, 22 Apr 2021 18:24:13 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B22252CBE5ED9; Thu, 22 Apr 2021 18:24:13 +0200 (CEST) Date: Thu, 22 Apr 2021 18:24:13 +0200 From: Peter Zijlstra To: kernel test robot Cc: Dietmar Eggemann , Valentin Schneider , LKML , x86@kernel.org, lkp@lists.01.org, lkp@intel.com, ying.huang@intel.com, feng.tang@intel.com, zhengjun.xing@intel.com, aubrey.li@linux.intel.com, yu.c.chen@intel.com Subject: Re: [sched,debug] 3b87f136f8: stress-ng.procfs.ops_per_sec -31.7% regression Message-ID: References: <20210422144258.GD6394@xsang-OptiPlex-9020> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210422144258.GD6394@xsang-OptiPlex-9020> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 22, 2021 at 10:42:58PM +0800, kernel test robot wrote: > > > Greeting, > > FYI, we noticed a -31.7% regression of stress-ng.procfs.ops_per_sec due to commit: > commit: 3b87f136f8fccddf7da016ab7d04bb3cf9b180f0 ("sched,debug: Convert sysctl sched_domains to debugfs") > on test machine: 96 threads Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 192G memory > 16865 ± 4% -31.7% 11516 ± 6% stress-ng.procfs.ops The patch in question removes a ton of procfs files, so this is just about expected. If this also lowers the procfs ops/s measure, this could be because all these procfs files were trivial. Some procfs files are expensive to read and collect lots of data, these files were trivial and fast, by removing them, the average time to read a procfs file might very well have increased. Over-all: -EDONTCARE.