| Message ID | 1520504950-8544-1-git-send-email-claudio@evidence.eu.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
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>
On Thu, Mar 8, 2018 at 11:29 AM, Claudio Scordino <claudio@evidence.eu.com> 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 I wouldn't break the line here > +void set_dl_rate_limit(struct sugov_cpu *sg_cpu, struct sugov_policy *sg_policy) and the name might be better as Viresh said, but overall Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > +{ > + if (cpu_util_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->util_dl) > + sg_policy->need_freq_update = true; > +} > + > static void sugov_update_single(struct update_util_data *hook, u64 time, > unsigned int flags) > { > @@ -273,6 +284,8 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, > sugov_set_iowait_boost(sg_cpu, time); > sg_cpu->last_update = time; > > + set_dl_rate_limit(sg_cpu, sg_policy); > + > if (!sugov_should_update_freq(sg_policy, time)) > return; > > @@ -354,6 +367,8 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, > > raw_spin_lock(&sg_policy->update_lock); > > + set_dl_rate_limit(sg_cpu, sg_policy); > + > sugov_get_util(sg_cpu); > sg_cpu->flags = flags; > > -- > 2.7.4 >
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) +{ + if (cpu_util_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->util_dl) + sg_policy->need_freq_update = true; +} + static void sugov_update_single(struct update_util_data *hook, u64 time, unsigned int flags) { @@ -273,6 +284,8 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, sugov_set_iowait_boost(sg_cpu, time); sg_cpu->last_update = time; + set_dl_rate_limit(sg_cpu, sg_policy); + if (!sugov_should_update_freq(sg_policy, time)) return; @@ -354,6 +367,8 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, raw_spin_lock(&sg_policy->update_lock); + set_dl_rate_limit(sg_cpu, sg_policy); + sugov_get_util(sg_cpu); sg_cpu->flags = flags;
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(+)