From 6e7499135db724539ca887b3aa64122502875c71 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Mon, 21 Sep 2020 09:24:24 +0200 Subject: [PATCH] sched/fair: Reduce busy load balance interval The busy_factor, which increases load balance interval when a cpu is busy, is set to 32 by default. This value generates some huge LB interval on large system like the THX2 made of 2 node x 28 cores x 4 threads. For such system, the interval increases from 112ms to 3584ms at MC level. And from 228ms to 7168ms at NUMA level. Even on smaller system, a lower busy factor has shown improvement on the fair distribution of the running time so let reduce it for all. Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Phil Auld Link: https://lkml.kernel.org/r/20200921072424.14813-5-vincent.guittot@linaro.org --- kernel/sched/topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 41df62884cea..a3a2417fec54 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1348,7 +1348,7 @@ sd_init(struct sched_domain_topology_level *tl, *sd = (struct sched_domain){ .min_interval = sd_weight, .max_interval = 2*sd_weight, - .busy_factor = 32, + .busy_factor = 16, .imbalance_pct = 117, .cache_nice_tries = 0, -- 2.20.1