diff options
| author | Morten Rasmussen <morten.rasmussen@arm.com> | 2015-02-03 13:54:11 +0000 |
|---|---|---|
| committer | Punit Agrawal <punit.agrawal@arm.com> | 2016-03-21 12:34:30 +0000 |
| commit | c6110ac05befce0b5e4bfb23b41b13140f4d6bc8 (patch) | |
| tree | b18068c16f2ad09dc8211bff9e49ecebf5f9ff46 | |
| parent | 298ee11fae708706e9c3bc9e8ae53bd2f7e2a0c2 (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>
| -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); |