If the buddy CPU is not full and currently idle, we trigger an Idle Load Balance to give it the opportunity to pull more tasks.
Signed-off-by: Vincent Guittot <[email protected]> --- kernel/sched/fair.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 874f330..954adfd 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5776,6 +5776,26 @@ end: clear_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)); } +static int check_nohz_buddy(int cpu) +{ + int buddy = per_cpu(sd_pack_buddy, cpu); + + if (sysctl_sched_packing_mode != SCHED_PACKING_FULL) + return false; + + /* No pack buddy for this CPU */ + if (buddy == -1) + return false; + + if (is_buddy_full(buddy)) + return false; + + if (cpumask_test_cpu(buddy, nohz.idle_cpus_mask)) + return true; + + return false; +} + /* * Current heuristic for kicking the idle load balancer in the presence * of an idle cpu is the system. @@ -5813,6 +5833,10 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu) if (rq->nr_running >= 2) goto need_kick; + /* the buddy is idle and not busy so we can pack */ + if (check_nohz_buddy(cpu)) + goto need_kick; + rcu_read_lock(); for_each_domain(cpu, sd) { struct sched_group *sg = sd->groups; -- 1.7.9.5 -- 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/
