From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752333AbeB1LG2 (ORCPT ); Wed, 28 Feb 2018 06:06:28 -0500 Received: from mail-wr0-f194.google.com ([209.85.128.194]:41950 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752263AbeB1LG0 (ORCPT ); Wed, 28 Feb 2018 06:06:26 -0500 X-Google-Smtp-Source: AH8x226z/olPWf+J/gQkUfzN1xNBWgN1AMpz3v4fp5nih2TaZfuEwEC4BkXshCPjeRW96bYPrXxX8w== From: Claudio Scordino To: Peter Zijlstra , "Rafael J . Wysocki" Cc: Claudio Scordino , Ingo Molnar , Patrick Bellasi , Dietmar Eggemann , Morten Rasmussen , Juri Lelli , Viresh Kumar , Vincent Guittot , Todd Kjos , Joel Fernandes , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] cpufreq: schedutil: rate limits for SCHED_DEADLINE Date: Wed, 28 Feb 2018 12:06:10 +0100 Message-Id: <1519815970-5686-1-git-send-email-claudio@evidence.eu.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the SCHED_DEADLINE scheduling class increases the CPU utilization, we should not wait for the rate limit, otherwise we may miss some deadline. Tests using rt-app on Exynos5422 with up to 10 SCHED_DEADLINE tasks have shown reductions of even 10% of deadline misses with a negligible increase of energy consumption (measured through Baylibre Cape). Signed-off-by: Claudio Scordino CC: Ingo Molnar CC: Patrick Bellasi CC: Dietmar Eggemann CC: Morten Rasmussen CC: Juri Lelli CC: Viresh Kumar CC: Vincent Guittot CC: Todd Kjos CC: Joel Fernandes CC: linux-pm@vger.kernel.org CC: linux-kernel@vger.kernel.org --- Changes from v1: - Logic moved from sugov_should_update_freq() to sugov_update_single()/_shared() to not duplicate data structures - Rate limit not ignored in case of "fast switch" --- kernel/sched/cpufreq_schedutil.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 7936f54..ca6ce72 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -273,6 +273,14 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, sugov_set_iowait_boost(sg_cpu, time); sg_cpu->last_update = time; + /* + * Make sugov_should_update_freq() ignore the rate limit when DL + * has increased the utilization. + */ + if ((cpu_util_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->util_dl) && + !(sg_policy->policy->fast_switch_enabled)) + sg_policy->need_freq_update = true; + if (!sugov_should_update_freq(sg_policy, time)) return; @@ -354,6 +362,14 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, raw_spin_lock(&sg_policy->update_lock); + /* + * Make sugov_should_update_freq() ignore the rate limit when DL + * has increased the utilization. + */ + if ((cpu_util_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->util_dl) && + !(sg_policy->policy->fast_switch_enabled)) + sg_policy->need_freq_update = true; + sugov_get_util(sg_cpu); sg_cpu->flags = flags; -- 2.7.4