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=-8.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 BD31EC4363A for ; Mon, 5 Oct 2020 06:51:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C93520657 for ; Mon, 5 Oct 2020 06:51:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Egux96Ob" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725911AbgJEGvh (ORCPT ); Mon, 5 Oct 2020 02:51:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725869AbgJEGvh (ORCPT ); Mon, 5 Oct 2020 02:51:37 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE3CEC0613CE for ; Sun, 4 Oct 2020 23:51:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=cYk7Obp2ahObSK3QU4wsH0HwLm9yxaSVt/cZVZIJRRg=; b=Egux96ObWB5/g7c2+G+4yqlRkL V05Rlh4LYcf8wi0KbCTnyvpS/wxR3IyM1OREFZHPAK/HbTCLZv6BpnHNM66UUd3KAQPIsagDjcGss dr0G5c+DFHV+N6suh4eiB8uafFPbaX8uhzXweHsZMvxpMfzV5YbyZRJfN8DiAdl2VMVGwznQERQs+ hDN+kNXr/CQLR4G+hvffXjuwnCA5UV4DAkIIR75IUiXhM/O4JtAJ3zDYsoVcJDQG2pQjgIrtjFcNJ 1MUfCZXco40kE6LajhYaEBmxnnxsGrGjpPPGkeNaiLAhD1azd3bt/szW3su3ds0usHJlkdJEAnEfl AS+ajliQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kPKKt-0002Te-FW; Mon, 05 Oct 2020 06:51:03 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id F0AB130377D; Mon, 5 Oct 2020 08:51:01 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DEFCC29E463CA; Mon, 5 Oct 2020 08:51:01 +0200 (CEST) Date: Mon, 5 Oct 2020 08:51:01 +0200 From: Peter Zijlstra To: Mel Gorman Cc: kernel test robot , Vincent Guittot , Ingo Molnar , Rik van Riel , Ben Segall , Dietmar Eggemann , Juri Lelli , Linus Torvalds , Mike Galbraith , Steven Rostedt , Thomas Gleixner , LKML , 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/fair] fcf0553db6: netperf.Throughput_Mbps -30.8% regression Message-ID: <20201005065101.GE2628@hirez.programming.kicks-ass.net> References: <20201004132716.GS393@shao2-debian> <20201004162108.GC3165@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201004162108.GC3165@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Oct 04, 2020 at 05:21:08PM +0100, Mel Gorman wrote: > On Sun, Oct 04, 2020 at 09:27:16PM +0800, kernel test robot wrote: > > Greeting, > > > > FYI, we noticed a -30.8% regression of netperf.Throughput_Mbps due to commit: > > > > > > commit: fcf0553db6f4c79387864f6e4ab4a891601f395e ("sched/fair: Remove meaningless imbalance calculation") > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > > > This commit was the start of a series that made large changes to load > balancing. The series was not bisect-safe and has since been reconciled > with the NUMA balancing. Any workload with a potential load balancing > problem has to be checked against the latest kernel to see if the problem > persists there. If it does, then tip/sched/core should be checked or > 5.10-rc1 when it comes out as tip has a few more LB changes pending. What Mel said ;-)