linux-kernel - Re: [PATCH v3 05/14] sched/cpufreq: uclamp: add utilization clamping for FAIR tasks

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Date:   Wed, 8 Aug 2018 15:18:59 +0200
From:   Vincent Guittot <vincent.guittot@...aro.org>
To:     Patrick Bellasi <patrick.bellasi@....com>
Cc:     linux-kernel <linux-kernel@...r.kernel.org>,
        "open list:THERMAL" <linux-pm@...r.kernel.org>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Tejun Heo <tj@...nel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        viresh kumar <viresh.kumar@...aro.org>,
        Paul Turner <pjt@...gle.com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Morten Rasmussen <morten.rasmussen@....com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Todd Kjos <tkjos@...gle.com>,
        Joel Fernandes <joelaf@...gle.com>,
        "Cc: Steve Muckle" <smuckle@...gle.com>, surenb@...gle.com
Subject: Re: [PATCH v3 05/14] sched/cpufreq: uclamp: add utilization clamping
 for FAIR tasks

Hi Patrick,

On Mon, 6 Aug 2018 at 18:40, Patrick Bellasi <patrick.bellasi@....com> wrote:
>

> @@ -222,8 +222,13 @@ static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)

>         util = cpu_util_cfs(rq);
> +       if (util)
> +               util = uclamp_util(cpu_of(rq), util);
>         util += cpu_util_rt(rq);
>
>         /*

> @@ -322,11 +328,24 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,

> +       max_boost = sg_cpu->iowait_boost_max;
> +       if (!cpu_util_rt(cpu_rq(sg_cpu->cpu)))
> +               max_boost = uclamp_util(sg_cpu->cpu, max_boost);
> +

> +static inline unsigned int uclamp_value(unsigned int cpu, int clamp_id)
> +{
> +       struct uclamp_cpu *uc_cpu = &cpu_rq(cpu)->uclamp;
> +
> +       if (uc_cpu->value[clamp_id] == UCLAMP_NOT_VALID)
> +               return uclamp_none(clamp_id);
> +
> +       return uc_cpu->value[clamp_id];
> +}
> +

> +static inline unsigned int uclamp_util(unsigned int cpu, unsigned int util)

using struct *rq rq instead of cpu as parameter would align
uclamp_util() interface with other cpu_util_*() interface and remove
some cpu_of(rq) and  cpu_rq(cpu)
> +{
> +       unsigned int min_util = uclamp_value(cpu, UCLAMP_MIN);
> +       unsigned int max_util = uclamp_value(cpu, UCLAMP_MAX);
> +
> +       return clamp(util, min_util, max_util);
> +}