From: Peter Zijlstra <peterz@infradead.org>
To: Douglas RAILLARD <douglas.raillard@arm.com>
Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
mingo@redhat.com, rjw@rjwysocki.net, viresh.kumar@linaro.org,
juri.lelli@redhat.com, vincent.guittot@linaro.org,
dietmar.eggemann@arm.com, qperret@qperret.net,
patrick.bellasi@matbug.net, dh.han@samsung.com
Subject: Re: [RFC PATCH v3 4/6] sched/cpufreq: Introduce sugov_cpu_ramp_boost
Date: Mon, 14 Oct 2019 16:33:21 +0200 [thread overview]
Message-ID: <20191014143321.GH2328@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20191011134500.235736-5-douglas.raillard@arm.com>
On Fri, Oct 11, 2019 at 02:44:58PM +0100, Douglas RAILLARD wrote:
> Use the utilization signals dynamic to detect when the utilization of a
> set of tasks starts increasing because of a change in tasks' behavior.
> This allows detecting when spending extra power for faster frequency
> ramp up response would be beneficial to the reactivity of the system.
>
> This ramp boost is computed as the difference
> util_avg-util_est_enqueued. This number somehow represents a lower bound
That reads funny, maybe 'as the difference between util_avg and
util_est_enqueued' ?
> of how much extra utilization this tasks is actually using, compared to
> our best current stable knowledge of it (which is util_est_enqueued).
>
> When the set of runnable tasks changes, the boost is disabled as the
> impact of blocked utilization on util_avg will make the delta with
> util_est_enqueued not very informative.
> @@ -561,6 +604,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
> }
> }
>
> +
> return get_next_freq(sg_policy, util, max);
> }
Surely we can do without this extra whitespace? :-)
next prev parent reply other threads:[~2019-10-14 14:33 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-11 13:44 [RFC PATCH v3 0/6] sched/cpufreq: Make schedutil energy aware Douglas RAILLARD
2019-10-11 13:44 ` [RFC PATCH v3 1/6] PM: Introduce em_pd_get_higher_freq() Douglas RAILLARD
2019-10-17 8:57 ` Dietmar Eggemann
2019-10-17 9:58 ` Dietmar Eggemann
2019-10-17 11:09 ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 2/6] sched/cpufreq: Attach perf domain to sugov policy Douglas RAILLARD
2019-10-17 8:57 ` Dietmar Eggemann
2019-10-17 10:22 ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 3/6] sched/cpufreq: Hook em_pd_get_higher_power() into get_next_freq() Douglas RAILLARD
2019-10-11 13:44 ` [RFC PATCH v3 4/6] sched/cpufreq: Introduce sugov_cpu_ramp_boost Douglas RAILLARD
2019-10-14 14:33 ` Peter Zijlstra [this message]
2019-10-14 15:32 ` Douglas Raillard
2019-10-17 8:57 ` Dietmar Eggemann
2019-10-17 11:19 ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 5/6] sched/cpufreq: Boost schedutil frequency ramp up Douglas RAILLARD
2019-10-17 9:21 ` Dietmar Eggemann
2019-10-11 13:45 ` [RFC PATCH v3 6/6] sched/cpufreq: Add schedutil_em_tp tracepoint Douglas RAILLARD
2019-10-14 14:53 ` [RFC PATCH v3 0/6] sched/cpufreq: Make schedutil energy aware Peter Zijlstra
2019-10-14 15:50 ` Douglas Raillard
2019-10-17 9:50 ` Peter Zijlstra
2019-10-17 11:11 ` Quentin Perret
2019-10-17 14:11 ` Peter Zijlstra
2019-10-18 7:44 ` Dietmar Eggemann
2019-10-18 7:59 ` Peter Zijlstra
2019-10-18 17:24 ` Douglas Raillard
2019-10-18 8:11 ` Peter Zijlstra
2019-10-17 14:23 ` Douglas Raillard
2019-10-17 14:53 ` Peter Zijlstra
2019-10-17 19:07 ` Peter Zijlstra
2019-10-18 11:46 ` Douglas Raillard
2019-10-18 12:07 ` Peter Zijlstra
2019-10-18 14:44 ` Douglas Raillard
2019-10-18 15:15 ` Vincent Guittot
2019-10-18 16:03 ` Douglas Raillard
2019-10-18 15:20 ` Vincent Guittot
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