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authorPaul Turner <pjt@google.com>2010-11-15 15:47:06 -0800
committerIngo Molnar <mingo@elte.hu>2010-11-18 13:27:49 +0100
commita7a4f8a752ec734b2eab904fc863d5dc873de338 (patch)
tree18b69c4cc0fc10cf6f0fe429308b25086942d921
parent67e86250f8ea7b8f7da53ac25ea73c6bd71f5cd9 (diff)
sched: Add sysctl_sched_shares_window
Introduce a new sysctl for the shares window and disambiguate it from sched_time_avg. A 10ms window appears to be a good compromise between accuracy and performance. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234938.112173964@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/sched.h1
-rw-r--r--kernel/sched_fair.c9
-rw-r--r--kernel/sysctl.c7
3 files changed, 16 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8abb8aa59664..840f1277492f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1900,6 +1900,7 @@ extern unsigned int sysctl_sched_migration_cost;
extern unsigned int sysctl_sched_nr_migrate;
extern unsigned int sysctl_sched_time_avg;
extern unsigned int sysctl_timer_migration;
+extern unsigned int sysctl_sched_shares_window;
int sched_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length,
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index b320753aa6c9..6c84439ce987 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -89,6 +89,13 @@ unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
+/*
+ * The exponential sliding window over which load is averaged for shares
+ * distribution.
+ * (default: 10msec)
+ */
+unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL;
+
static const struct sched_class fair_sched_class;
/**************************************************************
@@ -688,7 +695,7 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
static void update_cfs_load(struct cfs_rq *cfs_rq)
{
- u64 period = sched_avg_period();
+ u64 period = sysctl_sched_shares_window;
u64 now, delta;
unsigned long load = cfs_rq->load.weight;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 3132b25193db..9b520d74f052 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -333,6 +333,13 @@ static struct ctl_table kern_table[] = {
.proc_handler = proc_dointvec,
},
{
+ .procname = "sched_shares_window",
+ .data = &sysctl_sched_shares_window,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
.procname = "timer_migration",
.data = &sysctl_timer_migration,
.maxlen = sizeof(unsigned int),