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-rw-r--r--kernel/sched/fair.c38
1 files changed, 31 insertions, 7 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ffc99d8f0a95..2b89cd244b0d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5681,15 +5681,39 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
/* Earliest time when we have to do rebalance again */
unsigned long next_balance = jiffies + 60*HZ;
int update_next_balance = 0;
- int need_serialize;
+ int need_serialize, need_decay = 0;
+ u64 max_cost = 0;
update_blocked_averages(cpu);
rcu_read_lock();
for_each_domain(cpu, sd) {
+ /*
+ * Decay the newidle max times here because this is a regular
+ * visit to all the domains. Decay ~1% per second.
+ */
+ if (time_after(jiffies, sd->next_decay_max_lb_cost)) {
+ sd->max_newidle_lb_cost =
+ (sd->max_newidle_lb_cost * 253) / 256;
+ sd->next_decay_max_lb_cost = jiffies + HZ;
+ need_decay = 1;
+ }
+ max_cost += sd->max_newidle_lb_cost;
+
if (!(sd->flags & SD_LOAD_BALANCE))
continue;
+ /*
+ * Stop the load balance at this level. There is another
+ * CPU in our sched group which is doing load balancing more
+ * actively.
+ */
+ if (!continue_balancing) {
+ if (need_decay)
+ continue;
+ break;
+ }
+
interval = sd->balance_interval;
if (idle != CPU_IDLE)
interval *= sd->busy_factor;
@@ -5723,14 +5747,14 @@ out:
next_balance = sd->last_balance + interval;
update_next_balance = 1;
}
-
+ }
+ if (need_decay) {
/*
- * Stop the load balance at this level. There is another
- * CPU in our sched group which is doing load balancing more
- * actively.
+ * Ensure the rq-wide value also decays but keep it at a
+ * reasonable floor to avoid funnies with rq->avg_idle.
*/
- if (!continue_balancing)
- break;
+ rq->max_idle_balance_cost =
+ max((u64)sysctl_sched_migration_cost, max_cost);
}
rcu_read_unlock();