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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 EE703C43331 for ; Thu, 26 Mar 2020 13:31:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0C2D20737 for ; Thu, 26 Mar 2020 13:31:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Igz90rJc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727731AbgCZNbJ (ORCPT ); Thu, 26 Mar 2020 09:31:09 -0400 Received: from us-smtp-delivery-74.mimecast.com ([63.128.21.74]:28695 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726175AbgCZNbJ (ORCPT ); Thu, 26 Mar 2020 09:31:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585229468; h=from:from:reply-to:subject:subject: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=JszvOvoRUQGRKGqg0igxZKOZO39zKRLJjdSgTJKjaug=; b=Igz90rJc5cy0HfxA1hEv4PXQuuwxyL8x2ZG1KxzbU6TjCMjUeuUTtYK1MMdsykaCEcOZTG k5k3UnQ2KuX8QlCBDheJoTUKza7a9UFjjMNyHl1Lyg34v6B3iaQYd6tRvMSXwCj44Mfamd KmPUFqjYlpZ5v8ixFW0VzF1d/5lQxQI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-454-GC-7odwjPjakEKZ5OgNsMQ-1; Thu, 26 Mar 2020 09:31:03 -0400 X-MC-Unique: GC-7odwjPjakEKZ5OgNsMQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AF44C107ACCA; Thu, 26 Mar 2020 13:31:01 +0000 (UTC) Received: from lorien.usersys.redhat.com (ovpn-113-62.phx2.redhat.com [10.3.113.62]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 82A1F10002A5; Thu, 26 Mar 2020 13:30:57 +0000 (UTC) Date: Thu, 26 Mar 2020 09:30:55 -0400 From: Phil Auld To: Aubrey Li Cc: vincent.guittot@linaro.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, linux-kernel@vger.kernel.org, tim.c.chen@linux.intel.com, vpillai@digitalocean.com, joel@joelfernandes.org, Aubrey Li Subject: Re: [PATCH] sched/fair: Fix negative imbalance in imbalance calculation Message-ID: <20200326133055.GA5537@lorien.usersys.redhat.com> References: <1585201349-70192-1-git-send-email-aubrey.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1585201349-70192-1-git-send-email-aubrey.li@intel.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 26, 2020 at 01:42:29PM +0800 Aubrey Li wrote: > A negative imbalance value was observed after imbalance calculation, > this happens when the local sched group type is group_fully_busy, > and the average load of local group is greater than the selected > busiest group. Fix this problem by comparing the average load of the > local and busiest group before imbalance calculation formula. > > Suggested-by: Vincent Guittot > Signed-off-by: Aubrey Li > Cc: Phil Auld > --- > kernel/sched/fair.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index c1217bf..4a2ba3f 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -8761,6 +8761,14 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s > > sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) / > sds->total_capacity; > + /* > + * If the local group is more loaded than the selected > + * busiest group don't try to pull any tasks. > + */ > + if (local->avg_load >= busiest->avg_load) { > + env->imbalance = 0; > + return; > + } > } > > /* > -- > 2.7.4 > I like this one better. Thanks! Reviewed-by: Phil Auld --