From: Anson Huang <anson.huang@nxp.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Peng Fan <peng.fan@nxp.com>, Jacky Bai <ping.bai@nxp.com>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Peter Zijlstra <peterz@infradead.org>,
Paul McKenney <paulmck@linux.vnet.ibm.com>
Subject: RE: About CPU hot-plug stress test failed in cpufreq driver
Date: Wed, 11 Dec 2019 05:08:20 +0000 [thread overview]
Message-ID: <DB3PR0402MB3916E386A19549EA80230AF0F55A0@DB3PR0402MB3916.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <7233060.oySJ2cjCuV@kreacher>
>
> One more thing.
>
> Both of the previous patches would not fix the schedutil governor in which
> cpufreq_this_cpu_can_update() only is called in the fast_switch case and that
> is not when irq_works are used.
>
> So please discard the patch I have just posted and here is an updated patch
> that covers schedutil too, so please test this one instead.
>
> ---
> include/linux/cpufreq.h | 11 -----------
> include/linux/sched/cpufreq.h | 3 +++
> kernel/sched/cpufreq.c | 18 ++++++++++++++++++
> kernel/sched/cpufreq_schedutil.c | 8 +++-----
> 4 files changed, 24 insertions(+), 16 deletions(-)
>
> Index: linux-pm/include/linux/cpufreq.h
> ================================================================
> ===
> --- linux-pm.orig/include/linux/cpufreq.h
> +++ linux-pm/include/linux/cpufreq.h
> @@ -595,17 +595,6 @@ struct governor_attr {
> size_t count);
> };
>
> -static inline bool cpufreq_this_cpu_can_update(struct cpufreq_policy
> *policy) -{
> - /*
> - * Allow remote callbacks if:
> - * - dvfs_possible_from_any_cpu flag is set
> - * - the local and remote CPUs share cpufreq policy
> - */
> - return policy->dvfs_possible_from_any_cpu ||
> - cpumask_test_cpu(smp_processor_id(), policy->cpus);
> -}
> -
>
> /***************************************************************
> ******
> * FREQUENCY TABLE HELPERS *
>
> ****************************************************************
> *****/
> Index: linux-pm/kernel/sched/cpufreq.c
> ================================================================
> ===
> --- linux-pm.orig/kernel/sched/cpufreq.c
> +++ linux-pm/kernel/sched/cpufreq.c
> @@ -5,6 +5,8 @@
> * Copyright (C) 2016, Intel Corporation
> * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> */
> +#include <linux/cpufreq.h>
> +
> #include "sched.h"
>
> DEFINE_PER_CPU(struct update_util_data __rcu *,
> cpufreq_update_util_data); @@ -57,3 +59,19 @@ void
> cpufreq_remove_update_util_hook(int
> rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), NULL); }
> EXPORT_SYMBOL_GPL(cpufreq_remove_update_util_hook);
> +
> +/**
> + * cpufreq_this_cpu_can_update - Check if cpufreq policy can be updated.
> + * @policy: cpufreq policy to check.
> + *
> + * Return 'true' if:
> + * - the local and remote CPUs share @policy,
> + * - dvfs_possible_from_any_cpu is set in @policy and the local CPU is not
> going
> + * offline (in which it is not expected to run cpufreq updates any more).
> + */
> +bool cpufreq_this_cpu_can_update(struct cpufreq_policy *policy) {
> + return cpumask_test_cpu(smp_processor_id(), policy->cpus) ||
> + (policy->dvfs_possible_from_any_cpu &&
> +
> rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data)));
> +}
> Index: linux-pm/include/linux/sched/cpufreq.h
> ================================================================
> ===
> --- linux-pm.orig/include/linux/sched/cpufreq.h
> +++ linux-pm/include/linux/sched/cpufreq.h
> @@ -12,6 +12,8 @@
> #define SCHED_CPUFREQ_MIGRATION (1U << 1)
>
> #ifdef CONFIG_CPU_FREQ
> +struct cpufreq_policy;
> +
> struct update_util_data {
> void (*func)(struct update_util_data *data, u64 time, unsigned int
> flags); }; @@ -20,6 +22,7 @@ void cpufreq_add_update_util_hook(int cp
> void (*func)(struct update_util_data *data, u64 time,
> unsigned int flags));
> void cpufreq_remove_update_util_hook(int cpu);
> +bool cpufreq_this_cpu_can_update(struct cpufreq_policy *policy);
>
> static inline unsigned long map_util_freq(unsigned long util,
> unsigned long freq, unsigned long cap)
> Index: linux-pm/kernel/sched/cpufreq_schedutil.c
> ================================================================
> ===
> --- linux-pm.orig/kernel/sched/cpufreq_schedutil.c
> +++ linux-pm/kernel/sched/cpufreq_schedutil.c
> @@ -82,12 +82,10 @@ static bool sugov_should_update_freq(str
> * by the hardware, as calculating the frequency is pointless if
> * we cannot in fact act on it.
> *
> - * For the slow switching platforms, the kthread is always scheduled
> on
> - * the right set of CPUs and any CPU can find the next frequency and
> - * schedule the kthread.
> + * This is needed on the slow switching platforms too to prevent CPUs
> + * going offline from leaving stale IRQ work items behind.
> */
> - if (sg_policy->policy->fast_switch_enabled &&
> - !cpufreq_this_cpu_can_update(sg_policy->policy))
> + if (!cpufreq_this_cpu_can_update(sg_policy->policy))
> return false;
>
> if (unlikely(sg_policy->limits_changed)) {
The is patch is running so far so good on our i.MX8 platforms, both single cluster SoC
and dual clusters SoC, passed 3 hours test (> 5000 iterations) now and I will let it continue
to run for whole day.
And I will add this patch to our internal tree as a hot fix for now.
Thanks everyone a lot for help on this issue!
Anson
next prev parent reply other threads:[~2019-12-11 5:08 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <DB3PR0402MB391626A8ECFDC182C6EDCF8DF54E0@DB3PR0402MB3916.eurprd04.prod.outlook.com>
2019-11-21 9:35 ` About CPU hot-plug stress test failed in cpufreq driver Viresh Kumar
2019-11-21 10:13 ` Anson Huang
2019-11-21 10:53 ` Rafael J. Wysocki
2019-11-21 10:56 ` Rafael J. Wysocki
2019-11-22 5:15 ` Anson Huang
2019-11-22 9:59 ` Rafael J. Wysocki
2019-11-25 6:05 ` Anson Huang
2019-11-25 9:43 ` Anson Huang
2019-11-26 6:18 ` Viresh Kumar
2019-11-26 8:22 ` Anson Huang
2019-11-26 8:25 ` Viresh Kumar
2019-11-25 12:44 ` Rafael J. Wysocki
2019-11-26 8:57 ` Rafael J. Wysocki
2019-11-29 11:39 ` Rafael J. Wysocki
2019-11-29 13:44 ` Anson Huang
2019-12-05 8:53 ` Anson Huang
2019-12-05 10:48 ` Rafael J. Wysocki
2019-12-05 13:18 ` Anson Huang
2019-12-05 15:52 ` Rafael J. Wysocki
2019-12-09 10:31 ` Peng Fan
2019-12-09 10:37 ` Anson Huang
2019-12-09 10:56 ` Anson Huang
2019-12-09 11:23 ` Rafael J. Wysocki
2019-12-09 12:32 ` Anson Huang
2019-12-09 12:44 ` Rafael J. Wysocki
2019-12-09 14:18 ` Anson Huang
2019-12-10 5:39 ` Anson Huang
2019-12-10 5:53 ` Peng Fan
2019-12-10 7:05 ` Viresh Kumar
2019-12-10 8:22 ` Rafael J. Wysocki
2019-12-10 8:29 ` Anson Huang
2019-12-10 8:36 ` Viresh Kumar
2019-12-10 8:37 ` Peng Fan
2019-12-10 8:37 ` Rafael J. Wysocki
2019-12-10 8:43 ` Peng Fan
2019-12-10 8:45 ` Anson Huang
2019-12-10 8:50 ` Rafael J. Wysocki
2019-12-10 8:51 ` Anson Huang
2019-12-10 10:39 ` Rafael J. Wysocki
2019-12-10 10:54 ` Rafael J. Wysocki
2019-12-11 5:08 ` Anson Huang [this message]
2019-12-11 8:59 ` Peng Fan
2019-12-11 9:36 ` Rafael J. Wysocki
2019-12-11 9:43 ` Peng Fan
2019-12-11 9:52 ` Rafael J. Wysocki
2019-12-11 10:11 ` Peng Fan
2019-12-10 10:54 ` Viresh Kumar
2019-12-10 11:07 ` Rafael J. Wysocki
2019-12-10 8:57 ` Viresh Kumar
2019-12-10 11:03 ` Rafael J. Wysocki
2019-12-10 9:04 ` Rafael J. Wysocki
2019-12-10 8:31 ` Viresh Kumar
2019-12-10 8:12 ` Rafael J. Wysocki
2019-12-05 11:00 ` Viresh Kumar
2019-12-05 11:10 ` Rafael J. Wysocki
2019-12-05 11:17 ` Viresh Kumar
2019-11-21 10:37 ` Rafael J. Wysocki
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