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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 CB4F8C433E0 for ; Thu, 7 Jan 2021 17:41:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87270233FB for ; Thu, 7 Jan 2021 17:41:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728282AbhAGRlB (ORCPT ); Thu, 7 Jan 2021 12:41:01 -0500 Received: from foss.arm.com ([217.140.110.172]:36784 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726326AbhAGRlB (ORCPT ); Thu, 7 Jan 2021 12:41:01 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DF5B431B; Thu, 7 Jan 2021 09:40:15 -0800 (PST) Received: from e113632-lin (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8DBDD3F719; Thu, 7 Jan 2021 09:40:14 -0800 (PST) From: Valentin Schneider To: Vincent Guittot Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , linux-kernel Subject: Re: [PATCH 3/3 v2] sched/fair: reduce cases for active balance In-Reply-To: References: <20210107103325.30851-1-vincent.guittot@linaro.org> <20210107103325.30851-4-vincent.guittot@linaro.org> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/26.3 (x86_64-pc-linux-gnu) Date: Thu, 07 Jan 2021 17:40:11 +0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/01/21 13:20, Vincent Guittot wrote: > On Thu, 7 Jan 2021 at 12:26, Valentin Schneider > wrote: >> > @@ -9499,13 +9499,32 @@ asym_active_balance(struct lb_env *env) >> > } >> > >> > static inline bool >> > -voluntary_active_balance(struct lb_env *env) >> > +imbalanced_active_balance(struct lb_env *env) >> > +{ >> > + struct sched_domain *sd = env->sd; >> > + >> > + /* >> > + * The imbalanced case includes the case of pinned tasks preventing a fair >> > + * distribution of the load on the system but also the even distribution of the >> > + * threads on a system with spare capacity >> > + */ >> >> Do you mean s/imbalanced/migrate_task/? This part here will affect >> group_imbalanced, group_asym_packing, and some others. > > I really mean the imbalanced case which refers to the function name > and includes: > - the pinned tasks case aka group_imbalanced and which is the primary > target of this function ( which explains its name) > - but also the case where we want to evenly spread tasks on system > with spare capacity and removed this imbalance > But can't this also affect other group_types? calculate_imbalance() can set env->migration_type = migrate_task; for busiest->group_type > group_fully_busy