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 <[email protected]> cc: Peter Zijlstra <[email protected]> Signed-off-by: Morten Rasmussen <[email protected]> --- 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 33d3d81..2557774 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4554,6 +4554,7 @@ 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) @@ -4563,6 +4564,11 @@ 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 90284d1..199ee3a 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -83,3 +83,9 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
