Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751513AbdFFP4z (ORCPT ); Tue, 6 Jun 2017 11:56:55 -0400 Received: from mail-it0-f65.google.com ([209.85.214.65]:33062 "EHLO mail-it0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388AbdFFP4x (ORCPT ); Tue, 6 Jun 2017 11:56:53 -0400 MIME-Version: 1.0 In-Reply-To: <20170606092651.GC5103@vireshk-i7> References: <1488469507-32463-1-git-send-email-patrick.bellasi@arm.com> <1488469507-32463-2-git-send-email-patrick.bellasi@arm.com> <20170606092651.GC5103@vireshk-i7> From: "Rafael J. Wysocki" Date: Tue, 6 Jun 2017 17:56:51 +0200 X-Google-Sender-Auth: mt8G5YATx5mQLDMhpXl83lVMsEU Message-ID: Subject: Re: [PATCH 1/6] cpufreq: schedutil: reset sg_cpus's flags at IDLE enter To: Viresh Kumar Cc: Patrick Bellasi , Linux Kernel Mailing List , Linux PM , Steven Rostedt , Vincent Guittot , John Stultz , Juri Lelli , Todd Kjos , Tim Murray , Andres Oportus , Joel Fernandes , Morten Rasmussen , Dietmar Eggemann , Chris Redpath , Ingo Molnar , Peter Zijlstra , "Rafael J . Wysocki" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2661 Lines: 74 On Tue, Jun 6, 2017 at 11:26 AM, Viresh Kumar wrote: > On 02-03-17, 15:45, Patrick Bellasi wrote: >> diff --git a/include/linux/sched.h b/include/linux/sched.h >> index e2ed46d..739b29d 100644 >> --- a/include/linux/sched.h >> +++ b/include/linux/sched.h >> @@ -3653,6 +3653,7 @@ static inline unsigned long rlimit_max(unsigned int limit) >> #define SCHED_CPUFREQ_RT (1U << 0) >> #define SCHED_CPUFREQ_DL (1U << 1) >> #define SCHED_CPUFREQ_IOWAIT (1U << 2) >> +#define SCHED_CPUFREQ_IDLE (1U << 3) >> >> #define SCHED_CPUFREQ_RT_DL (SCHED_CPUFREQ_RT | SCHED_CPUFREQ_DL) >> >> diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c >> index fd46593..084a98b 100644 >> --- a/kernel/sched/cpufreq_schedutil.c >> +++ b/kernel/sched/cpufreq_schedutil.c >> @@ -281,6 +281,12 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, >> >> raw_spin_lock(&sg_policy->update_lock); >> >> + /* CPU is entering IDLE, reset flags without triggering an update */ >> + if (flags & SCHED_CPUFREQ_IDLE) { >> + sg_cpu->flags = 0; >> + goto done; >> + } >> + >> sg_cpu->util = util; >> sg_cpu->max = max; >> sg_cpu->flags = flags; >> @@ -293,6 +299,7 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, >> sugov_update_commit(sg_policy, time, next_f); >> } >> >> +done: >> raw_spin_unlock(&sg_policy->update_lock); >> } >> >> diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c >> index 0c00172..a844c91 100644 >> --- a/kernel/sched/idle_task.c >> +++ b/kernel/sched/idle_task.c >> @@ -29,6 +29,10 @@ pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf >> put_prev_task(rq, prev); >> update_idle_core(rq); >> schedstat_inc(rq->sched_goidle); >> + >> + /* kick cpufreq (see the comment in kernel/sched/sched.h). */ >> + cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_IDLE); >> + >> return rq->idle; >> } > > I was discussing about almost the same problem with Vincent today and we were > convinced to write exactly the same patch to solve that. And then I saw this old > thread again :) > > Why did this thread die completely ? Because nobody followed up? :-) > Can we at least get the patches which don't have any objections merged > separately first ? Yes, we can in general, but someone needs to "shepherd" them and I've been traveling lately. So, if there's anything that appears non-controversial and looks like it could be applied, the best way to make that happen would be to resend it. Thanks, Rafael