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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2008-10-17 19:27:02 +0200
committerIngo Molnar <mingo@elte.hu>2008-10-20 14:05:02 +0200
commitffda12a17a324103e9900fa1035309811eecbfe5 (patch)
tree79fe8aae79a41b467f2cdd055036b3017642a9f6 /kernel/sysctl.c
parentb0aa51b999c449e5e3f9faa1ee406e052d407fe7 (diff)
sched: optimize group load balancer
I noticed that tg_shares_up() unconditionally takes rq-locks for all cpus in the sched_domain. This hurts. We need the rq-locks whenever we change the weight of the per-cpu group sched entities. To allevate this a little, only change the weight when the new weight is at least shares_thresh away from the old value. This avoids the rq-lock for the top level entries, since those will never be re-weighted, and fuzzes the lower level entries a little to gain performance in semi-stable situations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r--kernel/sysctl.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 617d41e4d6a..3d804f41e64 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -276,6 +276,16 @@ static struct ctl_table kern_table[] = {
},
{
.ctl_name = CTL_UNNUMBERED,
+ .procname = "sched_shares_thresh",
+ .data = &sysctl_sched_shares_thresh,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &zero,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
.procname = "sched_child_runs_first",
.data = &sysctl_sched_child_runs_first,
.maxlen = sizeof(unsigned int),