Re: [PATCH 2/2] thermal: cpufreq_cooling: Reuse effective_cpu_util()

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Quentin Perret <qperret@google.com>
Cc: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Zhang Rui <rui.zhang@intel.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Daniel Kachhap <amit.kachhap@gmail.com>,
	Javi Merino <javi.merino@kernel.org>,
	Amit Kucheria <amit.kucheria@verdurent.com>,
	linux-kernel@vger.kernel.org, Rafael Wysocki <rjw@rjwysocki.net>,
	linux-pm@vger.kernel.org
Subject: Re: [PATCH 2/2] thermal: cpufreq_cooling: Reuse effective_cpu_util()
Date: Wed, 22 Jul 2020 14:43:38 +0530	[thread overview]
Message-ID: <20200722091338.syymxwgk6znnasvt@vireshk-mac-ubuntu> (raw)
In-Reply-To: <20200717104314.GB2385870@google.com>

On 17-07-20, 11:43, Quentin Perret wrote:
> On Friday 17 Jul 2020 at 11:33:05 (+0100), Quentin Perret wrote:
> > On Friday 17 Jul 2020 at 11:14:38 (+0100), Quentin Perret wrote:
> > > On Tuesday 14 Jul 2020 at 12:06:53 (+0530), Viresh Kumar wrote:
> > > >  /**
> > > > - * get_load() - get load for a cpu since last updated
> > > > + * get_load() - get current load for a cpu
> > > >   * @cpufreq_cdev:	&struct cpufreq_cooling_device for this cpu
> > > >   * @cpu:	cpu number
> > > > - * @cpu_idx:	index of the cpu in time_in_idle*
> > > > + * @cpu_idx:	index of the cpu
> > > >   *
> > > > - * Return: The average load of cpu @cpu in percentage since this
> > > > - * function was last called.
> > > > + * Return: The current load of cpu @cpu in percentage.
> > > >   */
> > > >  static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu,
> > > >  		    int cpu_idx)
> > > >  {
> > > > -	u32 load;
> > > > -	u64 now, now_idle, delta_time, delta_idle;
> > > > -	struct time_in_idle *idle_time = &cpufreq_cdev->idle_time[cpu_idx];
> > > > -
> > > > -	now_idle = get_cpu_idle_time(cpu, &now, 0);
> > > > -	delta_idle = now_idle - idle_time->time;
> > > > -	delta_time = now - idle_time->timestamp;
> > > > +	unsigned long util = cpu_util_cfs(cpu_rq(cpu));
> > > > +	unsigned long max = arch_scale_cpu_capacity(cpu);
> > > 
> > > Should we subtract the thermal PELT signal from max?

Makes sense to me, but I am not really good with this util and load
stuff and so would leave that to you guys to decide :)

-- 
viresh