From: Dietmar Eggemann <[email protected]> We do not want to miss out on the ability to pull a single remaining task from a potential source cpu towards an idle destination cpu if the energy aware system operates above the tipping point.
Add an extra criteria to need_active_balance() to kick off active load balance if the source cpu is over-utilized and has lower capacity than the destination cpu. cc: Ingo Molnar <[email protected]> cc: Peter Zijlstra <[email protected]> Signed-off-by: Morten Rasmussen <[email protected]> Signed-off-by: Dietmar Eggemann <[email protected]> --- kernel/sched/fair.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 48ecf02..97eb83e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7569,6 +7569,13 @@ static int need_active_balance(struct lb_env *env) return 1; } + if ((capacity_of(env->src_cpu) < capacity_of(env->dst_cpu)) && + env->src_rq->cfs.h_nr_running == 1 && + cpu_overutilized(env->src_cpu) && + !cpu_overutilized(env->dst_cpu)) { + return 1; + } + return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2); } @@ -7923,7 +7930,8 @@ static int idle_balance(struct rq *this_rq) this_rq->idle_stamp = rq_clock(this_rq); if (this_rq->avg_idle < sysctl_sched_migration_cost || - !this_rq->rd->overload) { + (!energy_aware() && !this_rq->rd->overload) || + (energy_aware() && !this_rq->rd->overutilized)) { rcu_read_lock(); sd = rcu_dereference_check_sched_domain(this_rq->sd); if (sd) -- 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/
