From: Peter Zijlstra <peterz@infradead.org>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>,
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, Quentin Perret <qperret@google.com>,
Rafael Wysocki <rjw@rjwysocki.net>,
linux-pm@vger.kernel.org, lukasz.luba@arm.com
Subject: Re: [PATCH 2/2] thermal: cpufreq_cooling: Reuse effective_cpu_util()
Date: Thu, 22 Oct 2020 13:39:09 +0200 [thread overview]
Message-ID: <20201022113909.GE2611@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20201022110656.gaphjv2tzhj4f5y6@vireshk-i7>
On Thu, Oct 22, 2020 at 04:36:56PM +0530, Viresh Kumar wrote:
> On 22-10-20, 11:05, Peter Zijlstra wrote:
> > On Thu, Oct 22, 2020 at 02:02:55PM +0530, Viresh Kumar wrote:
> > > One of the issues I see with this is that schedutil may not be
> > > available in all configurations and it is still absolutely fine to
> > > using the suggested helper to get the energy numbers in such cases, so
> > > we shouldn't really make it scheutil dependent.
> >
> > The only constraint on schedutil is SMP I think; aside from that it
> > should/could always be available.
> >
> > Given the trainwreck here:
> >
> > 20201022071145.GM2628@hirez.programming.kicks-ass.net
> >
> > (you're on Cc), I'm starting to lean more and more towards making it
> > unconditionally available (when SMP).
> >
> > Anybody forcing it off either sets performance (in which case we don't
> > care about energy usage anyway)
>
> I agree.
>
> > or they select one of the old (broken)
> > ondemand/conservative things and I don't give a crap.
>
> The other kernel layers, for example cpufreq-cooling in question here,
> don't really need to bother with the governor in use and should be
> able to get the energy numbers anyway. So for me, the energy number
> that the cpufreq-cooling stuff gets should be same irrespective of the
> governor in use, schedutil or ondemand.
>
> Having said that, schedutil really doesn't need to install the
> fallback (which you suggested earlier), rather the scheduler core can
> do that directly with cpufreq core and schedutil can also use the same
> fallback mechanism maybe ? And so we can avoid the exporting of stuff
> that way.
I suppose that could work, yes. It's a bit weird to have two
interactions with cpufreq, once through a governor and once outside it,
but I suppose I can live with that.
next prev parent reply other threads:[~2020-10-22 11:39 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 6:36 [PATCH 0/2] cpufreq_cooling: Get effective CPU utilization from scheduler Viresh Kumar
2020-07-14 6:36 ` [PATCH 1/2] sched/core: Rename and move schedutil_cpu_util to core.c Viresh Kumar
2020-07-14 12:52 ` Rafael J. Wysocki
2020-07-14 6:36 ` [PATCH 2/2] thermal: cpufreq_cooling: Reuse effective_cpu_util() Viresh Kumar
2020-07-14 8:23 ` Peter Zijlstra
2020-07-14 13:05 ` Rafael J. Wysocki
2020-07-15 7:32 ` Viresh Kumar
2020-07-15 12:47 ` Rafael J. Wysocki
2020-07-16 11:56 ` Peter Zijlstra
2020-07-16 14:24 ` Lukasz Luba
2020-07-16 15:43 ` Peter Zijlstra
2020-07-17 9:55 ` Lukasz Luba
2020-07-17 9:46 ` Vincent Guittot
2020-07-17 10:30 ` Lukasz Luba
2020-07-17 12:13 ` Vincent Guittot
2020-07-30 6:24 ` Viresh Kumar
2020-07-30 11:16 ` Lukasz Luba
2020-10-19 7:40 ` Viresh Kumar
2020-10-19 11:10 ` Lukasz Luba
2020-10-22 8:32 ` Viresh Kumar
2020-10-22 9:05 ` Peter Zijlstra
2020-10-22 11:06 ` Viresh Kumar
2020-10-22 11:30 ` Rafael J. Wysocki
2020-10-22 11:57 ` Peter Zijlstra
2020-10-22 12:07 ` Rafael J. Wysocki
2020-10-22 11:39 ` Peter Zijlstra [this message]
2020-07-17 10:14 ` Quentin Perret
2020-07-17 10:33 ` Quentin Perret
2020-07-17 10:43 ` Quentin Perret
2020-07-22 9:13 ` Viresh Kumar
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