Messages in this thread | | | Date | Thu, 8 Mar 2018 16:03:05 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH v3] cpufreq: schedutil: rate limits for SCHED_DEADLINE |
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On 08-03-18, 11:29, Claudio Scordino wrote: > When the SCHED_DEADLINE scheduling class increases the CPU utilization, > we should not wait for the rate limit, otherwise we may miss some > deadline. > > Tests using rt-app on Exynos5422 with up to 10 SCHED_DEADLINE tasks have > shown reductions of even 10% of deadline misses with a negligible > increase of energy consumption (measured through Baylibre Cape). > > Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> > CC: Ingo Molnar <mingo@redhat.com> > CC: Patrick Bellasi <patrick.bellasi@arm.com> > CC: Dietmar Eggemann <dietmar.eggemann@arm.com> > CC: Morten Rasmussen <morten.rasmussen@arm.com> > CC: Juri Lelli <juri.lelli@redhat.com> > CC: Viresh Kumar <viresh.kumar@linaro.org> > CC: Vincent Guittot <vincent.guittot@linaro.org> > CC: Todd Kjos <tkjos@android.com> > CC: Joel Fernandes <joelaf@google.com> > CC: linux-pm@vger.kernel.org > CC: linux-kernel@vger.kernel.org > --- > Changes from v2: > - Rate limit ignored also in case of "fast switch" > - Specific routine added > --- > Changes from v1: > - Logic moved from sugov_should_update_freq() to > sugov_update_single()/_shared() to not duplicate data structures > - Rate limit not ignored in case of "fast switch" > --- > kernel/sched/cpufreq_schedutil.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c > index 7936f54..13f9cce 100644 > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -260,6 +260,17 @@ static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) > static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } > #endif /* CONFIG_NO_HZ_COMMON */ > > +/* > + * Make sugov_should_update_freq() ignore the rate limit when DL > + * has increased the utilization. > + */ > +static inline > +void set_dl_rate_limit(struct sugov_cpu *sg_cpu, struct sugov_policy *sg_policy)
Maybe it could be renamed as ignore_dl_rate_limit() ? Lets see what others have to say. But looks fine otherwise.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
-- viresh
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