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Groups > linux.kernel > #1358600
| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity |
| Date | 2016-03-16 08:50 +0100 |
| Message-ID | <rdenp-5MN-23@gated-at.bofh.it> (permalink) |
| References | <rcteN-7Q2-3@gated-at.bofh.it> <rcteO-7Q2-17@gated-at.bofh.it> <rd50L-7UJ-27@gated-at.bofh.it> <rdenp-5MN-25@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Mar 15, 2016 at 03:27:21PM -0700, Michael Turquette wrote:
> That solution scales for the case where architectures have different
> methods. It doesn't scale for the case where cpufreq drivers or platform
> code within the same arch have competing implementations.
Sure it does; no matter what interface we use on x86 to set the DVFS
hints (ACPI, intel_p_state, whatever), using APERF/MPERF is the only
actual way of telling WTH the actual frequency was.
> I'm happy with it as a stop-gap, because it will initially work for
> arm{64} and x86, but we'll still need run-time selection of
> arch_scale_freq_capacity some day. Once we have that, I think that we
> should favor a run-time provided implementation over the arch-provided
> one.
Also, I'm thinking we don't need any of this. Your
cpufreq_scale_freq_capacity() is completely and utterly pointless. Since
its implementation simply provides whatever frequency we selected its
identical to not using frequency invariant load metrics and having
cpufreq use the !inv formula.
See:
lkml.kernel.org/r/20160309163930.GP6356@twins.programming.kicks-ass.net
Now, something else (power aware scheduling etc..) might need the freq
invariant stuff, but cpufreq (which we're concerned with here) does not
unless arch_scale_freq_capacity() does something else than simply return
the value we've set earlier.
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[PATCH 0/8] schedutil enhancements Michael Turquette <mturquette@baylibre.com> - 2016-03-14 06:30 +0100
[PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Michael Turquette <mturquette@baylibre.com> - 2016-03-14 06:30 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:30 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:50 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Steve Muckle <steve.muckle@linaro.org> - 2016-03-16 04:40 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Peter Zijlstra <peterz@infradead.org> - 2016-03-16 09:10 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Juri Lelli <Juri.Lelli@arm.com> - 2016-03-16 11:10 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Steve Muckle <steve.muckle@linaro.org> - 2016-03-16 19:00 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Michael Turquette <mturquette@baylibre.com> - 2016-03-16 23:10 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Juri Lelli <Juri.Lelli@arm.com> - 2016-03-17 10:40 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Steve Muckle <steve.muckle@linaro.org> - 2016-03-17 15:00 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Patrick Bellasi <patrick.bellasi@arm.com> - 2016-03-17 17:00 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-16 13:50 +0100
Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Michael Turquette <mturquette@baylibre.com> - 2016-03-16 23:10 +0100
[PATCH 1/8] sched/cpufreq: remove cpufreq_trigger_update() Michael Turquette <mturquette@baylibre.com> - 2016-03-14 06:30 +0100
Re: [PATCH 1/8] sched/cpufreq: remove cpufreq_trigger_update() Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:20 +0100
Re: [PATCH 1/8] sched/cpufreq: remove cpufreq_trigger_update() Peter Zijlstra <peterz@infradead.org> - 2016-03-15 23:00 +0100
Re: [PATCH 1/8] sched/cpufreq: remove cpufreq_trigger_update() Peter Zijlstra <peterz@infradead.org> - 2016-03-16 09:10 +0100
[PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Michael Turquette <mturquette@baylibre.com> - 2016-03-14 06:30 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:30 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Steve Muckle <steve.muckle@linaro.org> - 2016-03-16 05:00 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Peter Zijlstra <peterz@infradead.org> - 2016-03-16 08:50 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Vincent Guittot <vincent.guittot@linaro.org> - 2016-03-16 09:40 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Peter Zijlstra <peterz@infradead.org> - 2016-03-16 10:00 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Vincent Guittot <vincent.guittot@linaro.org> - 2016-03-16 10:20 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-16 13:40 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Peter Zijlstra <peterz@infradead.org> - 2016-03-16 14:20 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-16 14:30 +0100
Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Peter Zijlstra <peterz@infradead.org> - 2016-03-16 14:50 +0100
[PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Michael Turquette <mturquette@baylibre.com> - 2016-03-14 06:30 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-03-15 20:20 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Michael Turquette <mturquette@baylibre.com> - 2016-03-15 21:50 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-03-16 20:50 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Peter Zijlstra <peterz@infradead.org> - 2016-03-16 21:10 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-16 22:40 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:50 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Peter Zijlstra <peterz@infradead.org> - 2016-03-16 08:50 +0100
Re: [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Peter Zijlstra <peterz@infradead.org> - 2016-03-16 13:50 +0100
[PATCH 2/8] sched/fair: add margin to utilization update Michael Turquette <mturquette@baylibre.com> - 2016-03-14 06:30 +0100
Re: [PATCH 2/8] sched/fair: add margin to utilization update Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:20 +0100
Re: [PATCH 2/8] sched/fair: add margin to utilization update Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:50 +0100
Re: [PATCH 2/8] sched/fair: add margin to utilization update Steve Muckle <steve.muckle@linaro.org> - 2016-03-16 04:00 +0100
Re: [PATCH 2/8] sched/fair: add margin to utilization update Michael Turquette <mturquette@baylibre.com> - 2016-03-16 23:20 +0100
[PATCH 3/8] sched/cpufreq: new cfs capacity margin helpers Michael Turquette <mturquette@baylibre.com> - 2016-03-14 06:30 +0100
Re: [PATCH 3/8] sched/cpufreq: new cfs capacity margin helpers Peter Zijlstra <peterz@infradead.org> - 2016-03-15 22:20 +0100
Re: [PATCH 0/8] schedutil enhancements "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-16 01:10 +0100
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