Re: [PATCH v4] cpufreq: schedutil: rate limits for SCHED_DEADLINE
On Wednesday, March 14, 2018 2:27:53 AM CET Joel Fernandes wrote: > On Tue, Mar 13, 2018 at 4:15 AM, Viresh Kumar wrote: > > On 13-03-18, 11:35, 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 > >> Acked-by: Viresh Kumar > >> Reviewed-by: Rafael J. Wysocki > >> CC: Rafael J. Wysocki > >> CC: Viresh Kumar > >> CC: Patrick Bellasi > >> CC: Dietmar Eggemann > >> CC: Morten Rasmussen > >> CC: Juri Lelli > >> CC: Vincent Guittot > >> CC: Todd Kjos > >> CC: Joel Fernandes > >> CC: linux...@vger.kernel.org > >> CC: linux-kernel@vger.kernel.org > >> --- > >> Changes from v3: > >> - Specific routine renamed as ignore_dl_rate_limit() > > > > LGTM. Thanks. > > Nice! Thanks. OK, the patch doesn't seem to depend on anything in -tip, so I'm going to apply it. Thanks!
Re: [PATCH v4] cpufreq: schedutil: rate limits for SCHED_DEADLINE
On Tue, Mar 13, 2018 at 4:15 AM, Viresh Kumar wrote: > On 13-03-18, 11:35, 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 >> Acked-by: Viresh Kumar >> Reviewed-by: Rafael J. Wysocki >> CC: Rafael J. Wysocki >> CC: Viresh Kumar >> CC: Patrick Bellasi >> CC: Dietmar Eggemann >> CC: Morten Rasmussen >> CC: Juri Lelli >> CC: Vincent Guittot >> CC: Todd Kjos >> CC: Joel Fernandes >> CC: linux...@vger.kernel.org >> CC: linux-kernel@vger.kernel.org >> --- >> Changes from v3: >> - Specific routine renamed as ignore_dl_rate_limit() > > LGTM. Thanks. Nice! Thanks. - Joel
Re: [PATCH v4] cpufreq: schedutil: rate limits for SCHED_DEADLINE
On 13-03-18, 11:35, 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 > Acked-by: Viresh Kumar > Reviewed-by: Rafael J. Wysocki > CC: Rafael J. Wysocki > CC: Viresh Kumar > CC: Patrick Bellasi > CC: Dietmar Eggemann > CC: Morten Rasmussen > CC: Juri Lelli > CC: Vincent Guittot > CC: Todd Kjos > CC: Joel Fernandes > CC: linux...@vger.kernel.org > CC: linux-kernel@vger.kernel.org > --- > Changes from v3: > - Specific routine renamed as ignore_dl_rate_limit() LGTM. Thanks. -- viresh
[PATCH v4] cpufreq: schedutil: rate limits for SCHED_DEADLINE
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
Acked-by: Viresh Kumar
Reviewed-by: Rafael J. Wysocki
CC: Rafael J. Wysocki
CC: Viresh Kumar
CC: Patrick Bellasi
CC: Dietmar Eggemann
CC: Morten Rasmussen
CC: Juri Lelli
CC: Vincent Guittot
CC: Todd Kjos
CC: Joel Fernandes
CC: linux...@vger.kernel.org
CC: linux-kernel@vger.kernel.org
---
Changes from v3:
- Specific routine renamed as ignore_dl_rate_limit()
---
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 | 14 ++
1 file changed, 14 insertions(+)
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index feb5f89..2aeb1ca 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -257,6 +257,16 @@ 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 ignore_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)
{
@@ -270,6 +280,8 @@ static void sugov_update_single(struct update_util_data
*hook, u64 time,
sugov_set_iowait_boost(sg_cpu, time);
sg_cpu->last_update = time;
+ ignore_dl_rate_limit(sg_cpu, sg_policy);
+
if (!sugov_should_update_freq(sg_policy, time))
return;
@@ -351,6 +363,8 @@ sugov_update_shared(struct update_util_data *hook, u64
time, unsigned int flags)
raw_spin_lock(&sg_policy->update_lock);
+ ignore_dl_rate_limit(sg_cpu, sg_policy);
+
sugov_get_util(sg_cpu);
sg_cpu->flags = flags;
--
2.7.4
