lkml.org 
[lkml]   [2012]   [May]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC][PATCH 1/5] sched, fair: Let minimally loaded cpu balance the group
Currently we let the leftmost (or first idle) cpu acend the
sched_domain tree and perform load-balancing. The result is that the
busiest cpu in the group might be performing this function and pull
more load to itself. The next load balance pass will then try to
equalize this again.

Change this to pick the least loaded cpu to perform higher domain
balancing.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/sched/fair.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

Index: linux-2.6/kernel/sched/fair.c
===================================================================
--- linux-2.6.orig/kernel/sched/fair.c
+++ linux-2.6/kernel/sched/fair.c
@@ -3779,7 +3779,8 @@ static inline void update_sg_lb_stats(st
{
unsigned long load, max_cpu_load, min_cpu_load, max_nr_running;
int i;
- unsigned int balance_cpu = -1, first_idle_cpu = 0;
+ unsigned int balance_cpu = -1;
+ unsigned long balance_load = ~0UL;
unsigned long avg_load_per_task = 0;

if (local_group)
@@ -3795,12 +3796,11 @@ static inline void update_sg_lb_stats(st

/* Bias balancing toward cpus of our domain */
if (local_group) {
- if (idle_cpu(i) && !first_idle_cpu) {
- first_idle_cpu = 1;
+ load = target_load(i, load_idx);
+ if (load < balance_load || idle_cpu(i)) {
+ balance_load = load;
balance_cpu = i;
}
-
- load = target_load(i, load_idx);
} else {
load = source_load(i, load_idx);
if (load > max_cpu_load) {



\
 
 \ /
  Last update: 2012-05-01 20:41    [W:0.384 / U:0.948 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site