From ac91525a35e79b82a09fb1ed75ee547802f3bed1 Mon Sep 17 00:00:00 2001 From: Morten Rasmussen Date: Tue, 13 Jan 2015 13:45:51 +0000 Subject: [PATCH 46/92] 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 (cherry picked from commit e3b80d193dad157c720ec29496104126dbfc67ce) Signed-off-by: Gaku Inami --- kernel/sched/fair.c | 5 +++++ kernel/sched/features.h | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cb283ca..fa393d9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5291,6 +5291,11 @@ static void record_wakee(struct task_struct *p) } } +static inline bool energy_aware(void) +{ + return sched_feat(ENERGY_AWARE); +} + /* * Detect M:N waker/wakee relationships via a switching-frequency heuristic. * diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 69631fa..b634151 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -69,3 +69,8 @@ SCHED_FEAT(LB_MIN, false) SCHED_FEAT(ATTACH_AGE_LOAD, true) +/* + * Energy aware scheduling. Use platform energy model to guide scheduling + * decisions optimizing for energy efficiency. + */ +SCHED_FEAT(ENERGY_AWARE, false) -- 1.9.1