diff options
author | Claudio Scordino <[email protected]> | 2018-03-13 11:35:40 +0100 |
---|---|---|
committer | Thomas Gleixner <[email protected]> | 2018-03-23 22:48:22 +0100 |
commit | e97a90f7069b740575bcb1dae86596e0484b8957 (patch) | |
tree | 9886e76139ec6e5406b9cd341e9bb518551c3d1f | |
parent | d519329f72a6f36bc4f2b85452640cfe583b4f81 (diff) |
sched/cpufreq: Rate limits for SCHED_DEADLINE
When the SCHED_DEADLINE scheduling class increases the CPU utilization, it
should not wait for the rate limit, otherwise it 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 <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]>
Acked-by: Viresh Kumar <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Vincent Guittot <[email protected]>
Cc: [email protected]
Cc: Peter Zijlstra <[email protected]>
Cc: Morten Rasmussen <[email protected]>
Cc: Patrick Bellasi <[email protected]>
Cc: Todd Kjos <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
-rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 89fe78ecb88c..2b124811947d 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -267,6 +267,16 @@ 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) { @@ -279,6 +289,8 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, sugov_set_iowait_boost(sg_cpu, time, flags); sg_cpu->last_update = time; + ignore_dl_rate_limit(sg_cpu, sg_policy); + if (!sugov_should_update_freq(sg_policy, time)) return; @@ -356,6 +368,8 @@ sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags) sugov_set_iowait_boost(sg_cpu, time, flags); sg_cpu->last_update = time; + ignore_dl_rate_limit(sg_cpu, sg_policy); + if (sugov_should_update_freq(sg_policy, time)) { next_f = sugov_next_freq_shared(sg_cpu, time); sugov_update_commit(sg_policy, time, next_f); |