| From | Morten Rasmussen <> | Subject | [RFCv5 PATCH 14/46] sched: Make energy awareness a sched feature | Date | Tue, 7 Jul 2015 19:23:57 +0100 |
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This patch introduces the ENERGY_AWARE sched feature, which is implemented using jump labels when SCHED_DEBUG is defined. It is statically set false when SCHED_DEBUG is not defined. Hence this doesn't allow energy awareness to be enabled without SCHED_DEBUG. This sched_feature knob will be replaced later with a more appropriate control knob when things have matured a bit.
ENERGY_AWARE is based on per-entity load-tracking hence FAIR_GROUP_SCHED must be enable. This dependency isn't checked at compile time yet.
cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> --- kernel/sched/fair.c | 6 ++++++ kernel/sched/features.h | 6 ++++++ 2 files changed, 12 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d0df937..a95dad9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4781,6 +4781,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg) return wl; } + #else static long effective_load(struct task_group *tg, int cpu, long wl, long wg) @@ -4790,6 +4791,11 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg) #endif +static inline bool energy_aware(void) +{ + return sched_feat(ENERGY_AWARE); +} + static int wake_wide(struct task_struct *p) { int factor = this_cpu_read(sd_llc_size); diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 03d8072..92bc36e 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -91,3 +91,9 @@ SCHED_FEAT(NUMA_FAVOUR_HIGHER, true) */ SCHED_FEAT(NUMA_RESIST_LOWER, false) #endif + +/* + * Energy aware scheduling. Use platform energy model to guide scheduling + * decisions optimizing for energy efficiency. + */ +SCHED_FEAT(ENERGY_AWARE, false) -- 1.9.1
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