From af4ce8102bd5d682a404ca49dbb8b1d4d9066df6 Mon Sep 17 00:00:00 2001 From: "morten.rasmussen@arm.com" Date: Tue, 7 Jul 2015 19:23:57 +0100 Subject: sched: Make energy awareness a sched feature 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 cc: Peter Zijlstra Signed-off-by: Morten Rasmussen --- 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 b13033062485..a44b423fe825 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4761,6 +4761,7 @@ 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) @@ -4770,6 +4771,11 @@ 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 03d8072e8ab3..92bc36e0a66c 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) -- cgit v1.2.3