| Message ID | 1431459549-18343-35-git-send-email-morten.rasmussen@arm.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8efeb1d..e6d32e6 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8382,12 +8382,13 @@ static inline bool nohz_kick_needed(struct rq *rq) if (time_before(now, nohz.next_balance)) return false; - if (rq->nr_running >= 2) + if (rq->nr_running >= 2 && + (!energy_aware() || cpu_overutilized(cpu))) return true; rcu_read_lock(); sd = rcu_dereference(per_cpu(sd_busy, cpu)); - if (sd) { + if (sd && !energy_aware()) { sgc = sd->groups->sgc; nr_busy = atomic_read(&sgc->nr_busy_cpus);
With energy-aware scheduling enabled nohz_kick_needed() generates many nohz idle-balance kicks which lead to nothing when multiple tasks get packed on a single cpu to save energy. This causes unnecessary wake-ups and hence wastes energy. Make these conditions depend on !energy_aware() for now until the energy-aware nohz story gets sorted out. 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 | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)