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=-7.3 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,USER_AGENT_SANE_1 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 AE5A1C4708F for ; Tue, 1 Jun 2021 07:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92C6C6124B for ; Tue, 1 Jun 2021 07:59:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233272AbhFAIBF (ORCPT ); Tue, 1 Jun 2021 04:01:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:37476 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233069AbhFAIBD (ORCPT ); Tue, 1 Jun 2021 04:01:03 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1622534361; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ETA/uZ3RYpkBUVga1GOnLXdkl/xa1dO7W1HIUnISUfo=; b=qxjixrjODsCX8O311V2pZ4XZDFroeVhUc0n5yOMyNYPrPiS+hTiuZdT172p2qKvPFnby2q J7PWibYVNItSjk7JFRNi+Nnn6QHfMSiUvVowo0UrLojZpcpczmzvHFxC122Y345WfeXU6q k8fw73HXt03kPkdUM/TDEdLuvzAShZ0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1622534361; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ETA/uZ3RYpkBUVga1GOnLXdkl/xa1dO7W1HIUnISUfo=; b=wHR0OVOHiig4z3YxtYJ7jszKfMePoHoZDi8xUstskenJ7l0QPdZ5wvDBMWIGv1UrjF+hAZ pJo3cv94Cc7vRVBw== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 35272AD54; Tue, 1 Jun 2021 07:59:21 +0000 (UTC) Date: Tue, 1 Jun 2021 08:59:18 +0100 From: Mel Gorman To: "Song Bao Hua (Barry Song)" Cc: Peter Zijlstra , "vincent.guittot@linaro.org" , "mingo@redhat.com" , "dietmar.eggemann@arm.com" , "rostedt@goodmis.org" , "bsegall@google.com" , "valentin.schneider@arm.com" , "juri.lelli@redhat.com" , "bristot@redhat.com" , "linux-kernel@vger.kernel.org" , "guodong.xu@linaro.org" , yangyicong , tangchengchang , Linuxarm Subject: Re: [PATCH] sched: fair: don't depend on wake_wide if waker and wakee are already in same LLC Message-ID: <20210601075918.GP3672@suse.de> References: <20210526091057.1800-1-song.bao.hua@hisilicon.com> <7dd00a98d6454d5e92a7d9b936d1aa1c@hisilicon.com> <20210527121409.GK3672@suse.de> <07e4ba63a19c451ab47e6a636c400f4a@hisilicon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <07e4ba63a19c451ab47e6a636c400f4a@hisilicon.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 31, 2021 at 10:21:55PM +0000, Song Bao Hua (Barry Song) wrote: > The benchmark of tbenchs is still positive: > > tbench4 > > 5.13-rc4 5.13-rc4 > disable-llc-wakewide/ > > Hmean 1 514.87 ( 0.00%) 505.17 * -1.88%* > Hmean 2 914.45 ( 0.00%) 918.45 * 0.44%* > Hmean 4 1483.81 ( 0.00%) 1485.38 * 0.11%* > Hmean 8 2211.62 ( 0.00%) 2236.02 * 1.10%* > Hmean 16 2129.80 ( 0.00%) 2450.81 * 15.07%* > Hmean 32 5098.35 ( 0.00%) 5085.20 * -0.26%* > Hmean 64 4797.62 ( 0.00%) 4801.34 * 0.08%* > Hmean 80 4802.89 ( 0.00%) 4780.40 * -0.47%* > > I guess something which work across several LLC domains > cause performance regression. > > I wonder how your test will be like if you pin the testing > to CPUs within one LLC? > While I could do this, what would be the benefit? Running within one LLC would be running the test in one small fraction of the entire machine as the machine has multiple LLCs per NUMA node. A patch dealing with how the scheduler works with respect to LLC should take different configurations into consideration as best as possible. -- Mel Gorman SUSE Labs