lkml.org 
[lkml]   [2020]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4/4] sched/fair: reduce busy load balance interval
Date
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 <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 1a84b778755d..a8477c9e8569 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1336,7 +1336,7 @@ 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,
--
2.17.1
\
 
 \ /
  Last update: 2020-09-14 12:04    [W:0.256 / U:0.200 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site