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authorMike Galbraith <efault@gmx.de>2009-11-04 17:53:50 +0100
committerIngo Molnar <mingo@elte.hu>2009-11-04 19:13:48 +0100
commit1b9508f6831e10d53256825de8904caa22d1ca2c (patch)
tree1b9f62947a75432000cfe46b22071d2b09e5899a /kernel
parenta1f84a3ab8e002159498814eaa7e48c33752b04b (diff)
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sched: Rate-limit newidle
Rate limit newidle to migration_cost. It's a win for all stages of sysbench oltp tests. Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched.c22
-rw-r--r--kernel/sched_debug.c4
2 files changed, 25 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index ae026aad145b..f8492123b5d1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -589,6 +589,8 @@ struct rq {
u64 rt_avg;
u64 age_stamp;
+ u64 idle_stamp;
+ u64 avg_idle;
#endif
/* calc_load related fields */
@@ -2353,6 +2355,17 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
if (rq != orig_rq)
update_rq_clock(rq);
+ if (rq->idle_stamp) {
+ u64 delta = rq->clock - rq->idle_stamp;
+ u64 max = 2*sysctl_sched_migration_cost;
+
+ if (delta > max)
+ rq->avg_idle = max;
+ else
+ update_avg(&rq->avg_idle, delta);
+ rq->idle_stamp = 0;
+ }
+
WARN_ON(p->state != TASK_WAKING);
cpu = task_cpu(p);
@@ -4389,6 +4402,11 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
int pulled_task = 0;
unsigned long next_balance = jiffies + HZ;
+ this_rq->idle_stamp = this_rq->clock;
+
+ if (this_rq->avg_idle < sysctl_sched_migration_cost)
+ return;
+
for_each_domain(this_cpu, sd) {
unsigned long interval;
@@ -4403,8 +4421,10 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
interval = msecs_to_jiffies(sd->balance_interval);
if (time_after(next_balance, sd->last_balance + interval))
next_balance = sd->last_balance + interval;
- if (pulled_task)
+ if (pulled_task) {
+ this_rq->idle_stamp = 0;
break;
+ }
}
if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
/*
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index efb84409bc43..6988cf08f705 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -285,12 +285,16 @@ static void print_cpu(struct seq_file *m, int cpu)
#ifdef CONFIG_SCHEDSTATS
#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
+#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n);
P(yld_count);
P(sched_switch);
P(sched_count);
P(sched_goidle);
+#ifdef CONFIG_SMP
+ P64(avg_idle);
+#endif
P(ttwu_count);
P(ttwu_local);