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=-14.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 B6E53C4742C for ; Wed, 11 Nov 2020 08:23:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5AF3B20756 for ; Wed, 11 Nov 2020 08:23:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="lr+AcNhU"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="hfrFCo1p" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726459AbgKKIXh (ORCPT ); Wed, 11 Nov 2020 03:23:37 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:36524 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726391AbgKKIXa (ORCPT ); Wed, 11 Nov 2020 03:23:30 -0500 Date: Wed, 11 Nov 2020 08:23:28 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1605083008; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cUQC2Q7cay1Wpan7h8A9R+2dsmyxEmPRMWdof2w9Ghc=; b=lr+AcNhU/pX8aSkdVm0J0kutuSAiX+TVmCxYM9EyitUQX+l4pHeZQx9u7GOANHUJ2wPhRg YDj8Lqj5jwt6fFEkpvZfjXJ0jYr0f4dzwTcufIqAkpxWXxSburMlocfs9FbfwWLJje5Qak TCAswlKvnmZK7BpFvobOAf8i63fMv0z63xr/nx7i/eSABmFaPJFSVEnTYtXPK1Eh+woDWs diee+KGvBPnfrsDztFSTmgcxNgY9qknUyB0ESRSYh9VoyR80BVB6ZUoU5rU1RD1dGUfN9T g5KqmFjoipN5FUI6rdY2SsmWf+eaka1M5LNaLUV4f7SvTF6PmCKk6pCGTX2MUw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1605083008; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cUQC2Q7cay1Wpan7h8A9R+2dsmyxEmPRMWdof2w9Ghc=; b=hfrFCo1pFgK2qQmkZOrZaCk0aM+au6I3z+OZ/4M9cf9IOfGUxjC7JK0DpiKizQVfNLEliN PY38BGl3fL2SSuDQ== From: "tip-bot2 for Vincent Guittot" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/urgent] sched/fair: Ensure tasks spreading in LLC during LB Cc: Chris Mason , Rik van Riel , Vincent Guittot , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20201102102457.28808-1-vincent.guittot@linaro.org> References: <20201102102457.28808-1-vincent.guittot@linaro.org> MIME-Version: 1.0 Message-ID: <160508300800.11244.2752247858204582099.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/urgent branch of tip: Commit-ID: 16b0a7a1a0af9db6e008fecd195fe4d6cb366d83 Gitweb: https://git.kernel.org/tip/16b0a7a1a0af9db6e008fecd195fe4d6cb366d83 Author: Vincent Guittot AuthorDate: Mon, 02 Nov 2020 11:24:57 +01:00 Committer: Peter Zijlstra CommitterDate: Tue, 10 Nov 2020 18:38:48 +01:00 sched/fair: Ensure tasks spreading in LLC during LB schbench shows latency increase for 95 percentile above since: commit 0b0695f2b34a ("sched/fair: Rework load_balance()") Align the behavior of the load balancer with the wake up path, which tries to select an idle CPU which belongs to the LLC for a waking task. calculate_imbalance() will use nr_running instead of the spare capacity when CPUs share resources (ie cache) at the domain level. This will ensure a better spread of tasks on idle CPUs. Running schbench on a hikey (8cores arm64) shows the problem: tip/sched/core : schbench -m 2 -t 4 -s 10000 -c 1000000 -r 10 Latency percentiles (usec) 50.0th: 33 75.0th: 45 90.0th: 51 95.0th: 4152 *99.0th: 14288 99.5th: 14288 99.9th: 14288 min=0, max=14276 tip/sched/core + patch : schbench -m 2 -t 4 -s 10000 -c 1000000 -r 10 Latency percentiles (usec) 50.0th: 34 75.0th: 47 90.0th: 52 95.0th: 78 *99.0th: 94 99.5th: 94 99.9th: 94 min=0, max=94 Fixes: 0b0695f2b34a ("sched/fair: Rework load_balance()") Reported-by: Chris Mason Suggested-by: Rik van Riel Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Rik van Riel Tested-by: Rik van Riel Link: https://lkml.kernel.org/r/20201102102457.28808-1-vincent.guittot@linaro.org --- kernel/sched/fair.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index aa4c622..210b15f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9031,7 +9031,8 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s * emptying busiest. */ if (local->group_type == group_has_spare) { - if (busiest->group_type > group_fully_busy) { + if ((busiest->group_type > group_fully_busy) && + !(env->sd->flags & SD_SHARE_PKG_RESOURCES)) { /* * If busiest is overloaded, try to fill spare * capacity. This might end up creating spare capacity