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authorMorten Rasmussen <morten.rasmussen@arm.com>2015-01-13 13:45:51 +0000
committerLeo Yan <leo.yan@linaro.org>2016-05-10 16:49:50 +0800
commite496f328c87173fe188e91c6cd60197fb8e7e305 (patch)
tree5bce27d4f8cb6334c3547d7084b9ad96f213c331 /kernel
parentd8c8088f41033b1cea9d88149046e1f8bdb9ade0 (diff)
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 <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/fair.c5
-rw-r--r--kernel/sched/features.h5
2 files changed, 10 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 632163ef7628..efc65c3db6b5 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4651,6 +4651,11 @@ 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);
+}
+
/*
* Detect M:N waker/wakee relationships via a switching-frequency heuristic.
* A waker of many should wake a different task than the one last awakened
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 69631fa46c2f..b634151ce286 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -69,3 +69,8 @@ SCHED_FEAT(RT_RUNTIME_SHARE, true)
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)