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-rw-r--r--kernel/sched/fair.c28
1 files changed, 16 insertions, 12 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index aca16b843b7e..79e9e13c31ab 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2672,8 +2672,6 @@ static int select_idle_sibling(struct task_struct *p, int target)
/*
* Otherwise, iterate the domains and find an elegible idle cpu.
*/
- rcu_read_lock();
-
sd = rcu_dereference(per_cpu(sd_llc, target));
for_each_lower_domain(sd) {
sg = sd->groups;
@@ -2695,8 +2693,6 @@ next:
} while (sg != sd->groups);
}
done:
- rcu_read_unlock();
-
return target;
}
@@ -3086,6 +3082,8 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
* Fair scheduling class load-balancing methods:
*/
+static unsigned long __read_mostly max_load_balance_interval = HZ/10;
+
/*
* pull_task - move a task from a remote runqueue to the local runqueue.
* Both runqueues must be locked.
@@ -3778,6 +3776,11 @@ void update_group_power(struct sched_domain *sd, int cpu)
struct sched_domain *child = sd->child;
struct sched_group *group, *sdg = sd->groups;
unsigned long power;
+ unsigned long interval;
+
+ interval = msecs_to_jiffies(sd->balance_interval);
+ interval = clamp(interval, 1UL, max_load_balance_interval);
+ sdg->sgp->next_update = jiffies + interval;
if (!child) {
update_cpu_power(sd, cpu);
@@ -3885,12 +3888,15 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
* domains. In the newly idle case, we will allow all the cpu's
* to do the newly idle load balance.
*/
- if (idle != CPU_NEWLY_IDLE && local_group) {
- if (balance_cpu != this_cpu) {
- *balance = 0;
- return;
- }
- update_group_power(sd, this_cpu);
+ if (local_group) {
+ if (idle != CPU_NEWLY_IDLE) {
+ if (balance_cpu != this_cpu) {
+ *balance = 0;
+ return;
+ }
+ update_group_power(sd, this_cpu);
+ } else if (time_after_eq(jiffies, group->sgp->next_update))
+ update_group_power(sd, this_cpu);
}
/* Adjust by relative CPU power of the group */
@@ -4947,8 +4953,6 @@ static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
static DEFINE_SPINLOCK(balancing);
-static unsigned long __read_mostly max_load_balance_interval = HZ/10;
-
/*
* Scale the max load_balance interval with the number of CPUs in the system.
* This trades load-balance latency on larger machines for less cross talk.