From patchwork Tue Jul 7 18:24:07 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Morten Rasmussen X-Patchwork-Id: 6738451 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6F39EC05AC for ; Tue, 7 Jul 2015 19:00:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 84EEC206EC for ; Tue, 7 Jul 2015 19:00:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9217C20626 for ; Tue, 7 Jul 2015 19:00:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933383AbbGGTAD (ORCPT ); Tue, 7 Jul 2015 15:00:03 -0400 Received: from foss.arm.com ([217.140.101.70]:37552 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932873AbbGGSXC (ORCPT ); Tue, 7 Jul 2015 14:23:02 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 73D8847D; Tue, 7 Jul 2015 11:23:28 -0700 (PDT) Received: from e105550-lin.cambridge.arm.com (e105550-lin.cambridge.arm.com [10.2.131.193]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 59DE43F23A; Tue, 7 Jul 2015 11:22:59 -0700 (PDT) From: Morten Rasmussen To: peterz@infradead.org, mingo@redhat.com Cc: vincent.guittot@linaro.org, daniel.lezcano@linaro.org, Dietmar Eggemann , yuyang.du@intel.com, mturquette@baylibre.com, rjw@rjwysocki.net, Juri Lelli , sgurrappadi@nvidia.com, pang.xunlei@zte.com.cn, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: [RFCv5 PATCH 24/46] sched: Estimate energy impact of scheduling decisions Date: Tue, 7 Jul 2015 19:24:07 +0100 Message-Id: <1436293469-25707-25-git-send-email-morten.rasmussen@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1436293469-25707-1-git-send-email-morten.rasmussen@arm.com> References: <1436293469-25707-1-git-send-email-morten.rasmussen@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Adds a generic energy-aware helper function, energy_diff(), that calculates energy impact of adding, removing, and migrating utilization in the system. cc: Ingo Molnar cc: Peter Zijlstra Signed-off-by: Morten Rasmussen --- kernel/sched/fair.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 362e33b..bf1d34c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5026,6 +5026,57 @@ static unsigned int sched_group_energy(struct energy_env *eenv) return total_energy; } +/* + * energy_diff(): Estimate the energy impact of changing the utilization + * distribution. eenv specifies the change: utilisation amount, source, and + * destination cpu. Source or destination cpu may be -1 in which case the + * utilization is removed from or added to the system (e.g. task wake-up). If + * both are specified, the utilization is migrated. + */ +static int energy_diff(struct energy_env *eenv) +{ + struct sched_domain *sd; + struct sched_group *sg; + int sd_cpu = -1, energy_before = 0, energy_after = 0; + + struct energy_env eenv_before = { + .usage_delta = 0, + .src_cpu = eenv->src_cpu, + .dst_cpu = eenv->dst_cpu, + }; + + if (eenv->src_cpu == eenv->dst_cpu) + return 0; + + sd_cpu = (eenv->src_cpu != -1) ? eenv->src_cpu : eenv->dst_cpu; + sd = rcu_dereference(per_cpu(sd_ea, sd_cpu)); + + if (!sd) + return 0; /* Error */ + + sg = sd->groups; + do { + if (eenv->src_cpu != -1 && cpumask_test_cpu(eenv->src_cpu, + sched_group_cpus(sg))) { + eenv_before.sg_top = eenv->sg_top = sg; + energy_before += sched_group_energy(&eenv_before); + energy_after += sched_group_energy(eenv); + + /* src_cpu and dst_cpu may belong to the same group */ + continue; + } + + if (eenv->dst_cpu != -1 && cpumask_test_cpu(eenv->dst_cpu, + sched_group_cpus(sg))) { + eenv_before.sg_top = eenv->sg_top = sg; + energy_before += sched_group_energy(&eenv_before); + energy_after += sched_group_energy(eenv); + } + } while (sg = sg->next, sg != sd->groups); + + return energy_after-energy_before; +} + static int wake_wide(struct task_struct *p) { int factor = this_cpu_read(sd_llc_size);