From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932400AbdLOPkA (ORCPT ); Fri, 15 Dec 2017 10:40:00 -0500 Received: from mail-pf0-f196.google.com ([209.85.192.196]:44089 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932168AbdLOPj6 (ORCPT ); Fri, 15 Dec 2017 10:39:58 -0500 X-Google-Smtp-Source: ACJfBovcexqiPQx/t9mbnViq6T/qMWiZ+8chYJ+IoV6Nk6I5kEbNg+xNbY2GdvLRM4XD3bjeYZrRXw== From: Joel Fernandes To: linux-kernel@vger.kernel.org Cc: Joel Fernandes , Srinivas Pandruvada , Len Brown , "Rafael J. Wysocki" , Viresh Kumar , Ingo Molnar , Peter Zijlstra , Juri Lelli , Patrick Bellasi , Chris Redpath , Steve Muckle , Dietmar Eggemann , Vincent Guittot , Morten Ramussen , Frederic Weisbecker , Thomas Gleixner , Steven Rostedt , Saravana Kannan , Vikram Mulukutla , Rohit Jain , Atish Patra , Josef Bacik , EAS Dev , Android Kernel Subject: [PATCH 1/3] cpufreq: schedutil: Use idle_calls counter of the remote CPU Date: Fri, 15 Dec 2017 07:39:42 -0800 Message-Id: <20171215153944.220146-1-joelaf@google.com> X-Mailer: git-send-email 2.15.1.504.g5279b80103-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since the recent remote cpufreq callback work, its possible that a cpufreq update is triggered from a remote CPU. For single policies however, the current code uses the local CPU when trying to determine if the remote sg_cpu entered idle or is busy. This is incorrect. To remedy this, compare with the nohz tick idle_calls counter of the remote CPU. Acked-by: Viresh Kumar Signed-off-by: Joel Fernandes --- include/linux/tick.h | 1 + kernel/sched/cpufreq_schedutil.c | 2 +- kernel/time/tick-sched.c | 13 +++++++++++++ 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/tick.h b/include/linux/tick.h index f442d1a42025..7cc35921218e 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -119,6 +119,7 @@ extern void tick_nohz_idle_exit(void); extern void tick_nohz_irq_exit(void); extern ktime_t tick_nohz_get_sleep_length(void); extern unsigned long tick_nohz_get_idle_calls(void); +extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu); extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); #else /* !CONFIG_NO_HZ_COMMON */ diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 2f52ec0f1539..d6717a3331a1 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -244,7 +244,7 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util, #ifdef CONFIG_NO_HZ_COMMON static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { - unsigned long idle_calls = tick_nohz_get_idle_calls(); + unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu); bool ret = idle_calls == sg_cpu->saved_idle_calls; sg_cpu->saved_idle_calls = idle_calls; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 99578f06c8d4..77555faf6fbc 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -985,6 +985,19 @@ ktime_t tick_nohz_get_sleep_length(void) return ts->sleep_length; } +/** + * tick_nohz_get_idle_calls_cpu - return the current idle calls counter value + * for a particular CPU. + * + * Called from the schedutil frequency scaling governor in scheduler context. + */ +unsigned long tick_nohz_get_idle_calls_cpu(int cpu) +{ + struct tick_sched *ts = tick_get_tick_sched(cpu); + + return ts->idle_calls; +} + /** * tick_nohz_get_idle_calls - return the current idle calls counter value * -- 2.15.1.504.g5279b80103-goog