From: Dietmar Eggemann <[email protected]> Energy-aware load balancing bases on cpu usage so the upper bound of its operational range is a fully utilized cpu. Above this tipping point it makes more sense to use weighted_cpuload to preserve smp_nice. This patch implements the tipping point detection in update_sg_lb_stats as if one cpu is over-utilized the current energy-aware load balance operation will fall back into the conventional weighted load based one.
cc: Ingo Molnar <[email protected]> cc: Peter Zijlstra <[email protected]> Signed-off-by: Dietmar Eggemann <[email protected]> --- kernel/sched/fair.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6b79603..4849bad 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6723,6 +6723,10 @@ static inline void update_sg_lb_stats(struct lb_env *env, sgs->sum_weighted_load += weighted_cpuload(i); if (idle_cpu(i)) sgs->idle_cpus++; + + /* If cpu is over-utilized, bail out of ea */ + if (env->use_ea && cpu_overutilized(i, env->sd)) + env->use_ea = false; } /* Adjust by relative CPU capacity of the group */ -- 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/
