diff options
| author | Morten Rasmussen <morten.rasmussen@arm.com> | 2015-02-03 13:54:11 +0000 |
|---|---|---|
| committer | Leo Yan <leo.yan@linaro.org> | 2016-05-10 16:49:52 +0800 |
| commit | b71188bd2c52b6af022d687347eb4c7c29901580 (patch) | |
| tree | ba0e657386df12ad3c5792beca6420f17af9554e /kernel | |
| parent | 52b7b8a37c3da55885a9b7e60b2c4db6cf2dbeff (diff) | |
sched: Disable energy-unfriendly nohz kicks
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ae4f1ee9cf0c..7327221c991e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8259,12 +8259,13 @@ 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); |