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=-14.9 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 C8C83C4346E for ; Tue, 29 Sep 2020 07:57:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 82D8C20773 for ; Tue, 29 Sep 2020 07:57:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="HZPegXii"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="irpJBQ91" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727724AbgI2H5G (ORCPT ); Tue, 29 Sep 2020 03:57:06 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:44408 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727630AbgI2H4w (ORCPT ); Tue, 29 Sep 2020 03:56:52 -0400 Date: Tue, 29 Sep 2020 07:56:49 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1601366210; 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=EeB9bOENKeP52AlMH1PRmkkTBbYlI3ckFIEfrajbQ8o=; b=HZPegXiiVuMC6eFd4nIXeZ2hS9L8SEI2ZH0gLSQhRNXVNWyYJilQcCLz52ieXWvaxqUkBd gXfhuELNGnQzOfVY42nsgHiVZc4CLX/rHhxPXDKCsyX/plmf9XEEDwK1p7hk1T1hnkW/f5 5HVHslWJmLnzqlwma9+ym9o8lI1mK2kv8eTnwKFoe51/WKNXwJXWHHGA9vrgQjeIhgj8Zq zGiPQ+0SHlvP7P9aMctvsPcjSrc8OzShpVSIQXuhMkRsabQo4bMReR5vLB607zKij85LQl Y46Xa94m0FazPBpQvixCoaijM+GuQ22YuuplTru1St8C2ptSqP0ZBSslb3w9sQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1601366210; 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=EeB9bOENKeP52AlMH1PRmkkTBbYlI3ckFIEfrajbQ8o=; b=irpJBQ91OvtGnR2smDNoBffys1bTKpdfTkHXeGoDwmFM/39e/qQRhCNCOL8DaS6Iji5VV5 mQxgz76H+KgOxFAA== 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/core] sched/fair: Reduce minimal imbalance threshold Cc: Vincent Guittot , "Peter Zijlstra (Intel)" , Phil Auld , Hillf Danton , x86 , LKML In-Reply-To: <20200921072424.14813-3-vincent.guittot@linaro.org> References: <20200921072424.14813-3-vincent.guittot@linaro.org> MIME-Version: 1.0 Message-ID: <160136620949.7002.18026460832388099077.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/core branch of tip: Commit-ID: 2208cdaa56c957e20d8e16f28819aeb47851cb1e Gitweb: https://git.kernel.org/tip/2208cdaa56c957e20d8e16f28819aeb47851cb1e Author: Vincent Guittot AuthorDate: Mon, 21 Sep 2020 09:24:22 +02:00 Committer: Peter Zijlstra CommitterDate: Fri, 25 Sep 2020 14:23:26 +02:00 sched/fair: Reduce minimal imbalance threshold The 25% default imbalance threshold for DIE and NUMA domain is large enough to generate significant unfairness between threads. A typical example is the case of 11 threads running on 2x4 CPUs. The imbalance of 20% between the 2 groups of 4 cores is just low enough to not trigger the load balance between the 2 groups. We will have always the same 6 threads on one group of 4 CPUs and the other 5 threads on the other group of CPUS. With a fair time sharing in each group, we ends up with +20% running time for the group of 5 threads. Consider decreasing the imbalance threshold for overloaded case where we use the load to balance task and to ensure fair time sharing. Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Phil Auld Acked-by: Hillf Danton Link: https://lkml.kernel.org/r/20200921072424.14813-3-vincent.guittot@linaro.org --- kernel/sched/topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 249bec7..41df628 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1349,7 +1349,7 @@ sd_init(struct sched_domain_topology_level *tl, .min_interval = sd_weight, .max_interval = 2*sd_weight, .busy_factor = 32, - .imbalance_pct = 125, + .imbalance_pct = 117, .cache_nice_tries = 0,