Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:60062 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbdL3PZg (ORCPT ); Sat, 30 Dec 2017 10:25:36 -0500 Subject: Patch "cpufreq: schedutil: Use idle_calls counter of the remote CPU" has been added to the 4.14-stable tree To: joelaf@google.com, gregkh@linuxfoundation.org, peterz@infradead.org, rafael.j.wysocki@intel.com, viresh.kumar@linaro.org Cc: , From: Date: Sat, 30 Dec 2017 16:24:51 +0100 Message-ID: <151464749119346@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled cpufreq: schedutil: Use idle_calls counter of the remote CPU to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cpufreq-schedutil-use-idle_calls-counter-of-the-remote-cpu.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From 466a2b42d67644447a1765276259a3ea5531ddff Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Thu, 21 Dec 2017 02:22:45 +0100 Subject: cpufreq: schedutil: Use idle_calls counter of the remote CPU From: Joel Fernandes commit 466a2b42d67644447a1765276259a3ea5531ddff upstream. 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. Fixes: 674e75411fc2 (sched: cpufreq: Allow remote cpufreq callbacks) Acked-by: Viresh Kumar Acked-by: Peter Zijlstra (Intel) Signed-off-by: Joel Fernandes Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- include/linux/tick.h | 1 + kernel/sched/cpufreq_schedutil.c | 2 +- kernel/time/tick-sched.c | 13 +++++++++++++ 3 files changed, 15 insertions(+), 1 deletion(-) --- 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 */ --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -244,7 +244,7 @@ static void sugov_iowait_boost(struct su #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; --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1010,6 +1010,19 @@ ktime_t tick_nohz_get_sleep_length(void) } /** + * 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 * * Called from the schedutil frequency scaling governor in scheduler context. Patches currently in stable-queue which might be from joelaf@google.com are queue-4.14/cpufreq-schedutil-use-idle_calls-counter-of-the-remote-cpu.patch