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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 1BB1EC2D0DB for ; Fri, 24 Jan 2020 12:43:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED4612070A for ; Fri, 24 Jan 2020 12:43:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388119AbgAXMnS (ORCPT ); Fri, 24 Jan 2020 07:43:18 -0500 Received: from foss.arm.com ([217.140.110.172]:51268 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387746AbgAXMnQ (ORCPT ); Fri, 24 Jan 2020 07:43:16 -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 B39681045; Fri, 24 Jan 2020 04:43:15 -0800 (PST) Received: from e113632-lin.cambridge.arm.com (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7E2623F68E; Fri, 24 Jan 2020 04:43:14 -0800 (PST) From: Valentin Schneider To: linux-kernel@vger.kernel.org Cc: mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, morten.rasmussen@arm.com, qperret@google.com, adharmap@codeaurora.org Subject: [PATCH 2/3] sched/topology: Remove SD_BALANCE_WAKE on asymmetric capacity systems Date: Fri, 24 Jan 2020 12:42:54 +0000 Message-Id: <20200124124255.1095-3-valentin.schneider@arm.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200124124255.1095-1-valentin.schneider@arm.com> References: <20200124124255.1095-1-valentin.schneider@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Morten Rasmussen SD_BALANCE_WAKE was previously added to lower sched_domain levels on asymmetric CPU capacity systems by commit 9ee1cda5ee25 ("sched/core: Enable SD_BALANCE_WAKE for asymmetric capacity systems") to enable the use of find_idlest_cpu() and friends to find an appropriate CPU for tasks. That responsibility has now been shifted to select_idle_sibling() and friends, and hence the flag can be removed. Note that this causes asymmetric CPU capacity systems to no longer enter the slow wakeup path (find_idlest_cpu()) on wakeups - only on execs and forks (which is aligned with all other mainline topologies). Signed-off-by: Morten Rasmussen [Changelog tweaks] Signed-off-by: Valentin Schneider --- kernel/sched/topology.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index dfb64c08a407a..00911884b7e7a 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1374,18 +1374,9 @@ sd_init(struct sched_domain_topology_level *tl, * Convert topological properties into behaviour. */ - if (sd->flags & SD_ASYM_CPUCAPACITY) { - struct sched_domain *t = sd; - - /* - * Don't attempt to spread across CPUs of different capacities. - */ - if (sd->child) - sd->child->flags &= ~SD_PREFER_SIBLING; - - for_each_lower_domain(t) - t->flags |= SD_BALANCE_WAKE; - } + /* Don't attempt to spread across CPUs of different capacities. */ + if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child) + sd->child->flags &= ~SD_PREFER_SIBLING; if (sd->flags & SD_SHARE_CPUCAPACITY) { sd->imbalance_pct = 110; -- 2.24.0