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From: Matthias Kaehlcke <mka@chromium.org>
To: Quentin Perret <quentin.perret@arm.com>
Cc: peterz@infradead.org, rjw@rjwysocki.net,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	gregkh@linuxfoundation.org, mingo@redhat.com,
	dietmar.eggemann@arm.com, morten.rasmussen@arm.com,
	chris.redpath@arm.com, patrick.bellasi@arm.com,
	valentin.schneider@arm.com, vincent.guittot@linaro.org,
	thara.gopinath@linaro.org, viresh.kumar@linaro.org,
	tkjos@google.com, joel@joelfernandes.org, smuckle@google.com,
	adharmap@codeaurora.org, skannan@codeaurora.org,
	pkondeti@codeaurora.org, juri.lelli@redhat.com,
	edubezval@gmail.com, srinivas.pandruvada@linux.intel.com,
	currojerez@riseup.net, javi.merino@kernel.org
Subject: Re: [PATCH v10 15/15] OPTIONAL: cpufreq: dt: Register an Energy Model
Date: Tue, 8 Jan 2019 12:38:13 -0800	[thread overview]
Message-ID: <20190108203813.GS261387@google.com> (raw)
In-Reply-To: <20181203095628.11858-16-quentin.perret@arm.com>

Hi Quentin,

On Mon, Dec 03, 2018 at 09:56:28AM +0000, Quentin Perret wrote:
> *******************************************************************
> * This patch illustrates the usage of the newly introduced Energy *
> * Model framework and isn't supposed to be merged as-is.          *
> *******************************************************************
> 
> The Energy Model framework provides an API to register the active power
> of CPUs. Call this API from the cpufreq-dt driver with an estimation
> of the power as P = C * V^2 * f with C, V, and f respectively the
> capacitance of the CPU and the voltage and frequency of the OPP.
> 
> The CPU capacitance is read from the "dynamic-power-coefficient" DT
> binding (originally introduced for thermal/IPA), and the voltage and
> frequency values from PM_OPP.
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Signed-off-by: Quentin Perret <quentin.perret@arm.com>
> ---
>  drivers/cpufreq/cpufreq-dt.c | 48 +++++++++++++++++++++++++++++++++++-
>  1 file changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> index e58bfcb1169e..4cfef5554d86 100644
> --- a/drivers/cpufreq/cpufreq-dt.c
> +++ b/drivers/cpufreq/cpufreq-dt.c
> @@ -16,6 +16,7 @@
>  #include <linux/cpu_cooling.h>
>  #include <linux/cpufreq.h>
>  #include <linux/cpumask.h>
> +#include <linux/energy_model.h>
>  #include <linux/err.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> @@ -150,8 +151,50 @@ static int resources_available(void)
>  	return 0;
>  }
>  
> +static int __maybe_unused of_est_power(unsigned long *mW, unsigned long *KHz,
> +				       int cpu)
> +{
> +	unsigned long mV, Hz, MHz;
> +	struct device *cpu_dev;
> +	struct dev_pm_opp *opp;
> +	struct device_node *np;
> +	u32 cap;
> +	u64 tmp;
> +
> +	cpu_dev = get_cpu_device(cpu);
> +	if (!cpu_dev)
> +		return -ENODEV;
> +
> +	np = of_node_get(cpu_dev->of_node);
> +	if (!np)
> +		return -EINVAL;
> +
> +	if (of_property_read_u32(np, "dynamic-power-coefficient", &cap))
> +		return -EINVAL;
> +
> +	Hz = *KHz * 1000;
> +	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &Hz);
> +	if (IS_ERR(opp))
> +		return -EINVAL;
> +
> +	mV = dev_pm_opp_get_voltage(opp) / 1000;
> +	dev_pm_opp_put(opp);
> +	if (!mV)
> +		return -EINVAL;
> +
> +	MHz = Hz / 1000000;
> +	tmp = (u64)cap * mV * mV * MHz;
> +	do_div(tmp, 1000000000);
> +
> +	*mW = (unsigned long)tmp;
> +	*KHz = Hz / 1000;
> +
> +	return 0;
> +}
> +
>  static int cpufreq_init(struct cpufreq_policy *policy)
>  {
> +	struct em_data_callback em_cb = EM_DATA_CB(of_est_power);
>  	struct cpufreq_frequency_table *freq_table;
>  	struct opp_table *opp_table = NULL;
>  	struct private_data *priv;
> @@ -160,7 +203,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
>  	unsigned int transition_latency;
>  	bool fallback = false;
>  	const char *name;
> -	int ret;
> +	int ret, nr_opp;
>  
>  	cpu_dev = get_cpu_device(policy->cpu);
>  	if (!cpu_dev) {
> @@ -237,6 +280,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
>  		ret = -EPROBE_DEFER;
>  		goto out_free_opp;
>  	}
> +	nr_opp = ret;
>  
>  	if (fallback) {
>  		cpumask_setall(policy->cpus);
> @@ -280,6 +324,8 @@ static int cpufreq_init(struct cpufreq_policy *policy)
>  	policy->cpuinfo.transition_latency = transition_latency;
>  	policy->dvfs_possible_from_any_cpu = true;
>  
> +	em_register_perf_domain(policy->cpus, nr_opp, &em_cb);

Shouldn't there also be a function to unregister a perf domain to be
called from cpufreq_exit()?

->exit() is called on suspend when the CPUs are taken offline, and
->init() on resume, hence em_register_perf_domain() is called multiple
times, but without doing any cleanup.

Cheers

Matthias

  reply	other threads:[~2019-01-08 20:38 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-03  9:56 [PATCH v10 00/15] Energy Aware Scheduling Quentin Perret
2018-12-03  9:56 ` [PATCH v10 01/15] sched: Relocate arch_scale_cpu_capacity Quentin Perret
2018-12-11 15:32   ` [tip:sched/core] sched/topology: Relocate arch_scale_cpu_capacity() to the internal header tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 02/15] sched/cpufreq: Prepare schedutil for Energy Aware Scheduling Quentin Perret
2018-12-11 12:01   ` Rafael J. Wysocki
2018-12-11 12:17     ` Quentin Perret
2018-12-11 12:22       ` Rafael J. Wysocki
2018-12-11 12:24         ` Quentin Perret
2018-12-11 15:33   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 03/15] PM: Introduce an Energy Model management framework Quentin Perret
2018-12-11 15:33   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 04/15] PM / EM: Expose the Energy Model in sysfs Quentin Perret
2018-12-11 14:18   ` Ingo Molnar
2018-12-11 15:04     ` Quentin Perret
2018-12-03  9:56 ` [PATCH v10 05/15] sched/topology: Reference the Energy Model of CPUs when available Quentin Perret
2018-12-11 15:34   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 06/15] sched/topology: Lowest CPU asymmetry sched_domain level pointer Quentin Perret
2018-12-11 15:34   ` [tip:sched/core] sched/topology: Add lowest " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 07/15] sched/topology: Disable EAS on inappropriate platforms Quentin Perret
2018-12-11 15:35   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 08/15] sched/topology: Make Energy Aware Scheduling depend on schedutil Quentin Perret
2018-12-11 15:36   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 09/15] sched: Introduce sched_energy_present static key Quentin Perret
2018-12-11 15:36   ` [tip:sched/core] sched/toplogy: Introduce the 'sched_energy_present' " tip-bot for Quentin Perret
2018-12-13 13:56     ` Quentin Perret
2018-12-03  9:56 ` [PATCH v10 10/15] sched: Introduce a sysctl for Energy Aware Scheduling Quentin Perret
2018-12-11 14:15   ` Ingo Molnar
2018-12-11 14:49     ` Quentin Perret
2018-12-13 14:03       ` Peter Zijlstra
2019-01-21 11:35   ` [tip:sched/core] sched/topology: " tip-bot for Quentin Perret
2019-01-21 13:51   ` tip-bot for Quentin Perret
2019-01-27 11:34   ` tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 11/15] sched/fair: Clean-up update_sg_lb_stats parameters Quentin Perret
2018-12-11 15:37   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 12/15] sched: Add over-utilization/tipping point indicator Quentin Perret
2018-12-11 15:37   ` [tip:sched/core] sched/fair: " tip-bot for Morten Rasmussen
2018-12-03  9:56 ` [PATCH v10 13/15] sched/fair: Introduce an energy estimation helper function Quentin Perret
2018-12-11 15:38   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 14/15] sched/fair: Select an energy-efficient CPU on task wake-up Quentin Perret
2018-12-11 15:39   ` [tip:sched/core] " tip-bot for Quentin Perret
2018-12-03  9:56 ` [PATCH v10 15/15] OPTIONAL: cpufreq: dt: Register an Energy Model Quentin Perret
2019-01-08 20:38   ` Matthias Kaehlcke [this message]
2019-01-09 10:57     ` Quentin Perret
2019-01-09 18:14       ` Matthias Kaehlcke
2019-01-10  9:08         ` Quentin Perret

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