sched: Fix wake_affine() vs RT tasks
Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT
tasks), wake_affine() goes funny on RT tasks due to them still having a
!0 weight and wake_affine() still subtracts that from the rq weight.
Since nobody should be using se->weight for RT tasks, set the value to
zero. Also, since we now use ->cpu_power to normalize rq weights to
account for RT cpu usage, add that factor into the imbalance computation.
Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1275316109.27810.22969.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index d484081..f8b8996 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -544,6 +544,8 @@
struct root_domain *rd;
struct sched_domain *sd;
+ unsigned long cpu_power;
+
unsigned char idle_at_tick;
/* For active balancing */
int post_schedule;
@@ -1499,24 +1501,9 @@
return max(rq->cpu_load[type-1], total);
}
-static struct sched_group *group_of(int cpu)
-{
- struct sched_domain *sd = rcu_dereference_sched(cpu_rq(cpu)->sd);
-
- if (!sd)
- return NULL;
-
- return sd->groups;
-}
-
static unsigned long power_of(int cpu)
{
- struct sched_group *group = group_of(cpu);
-
- if (!group)
- return SCHED_LOAD_SCALE;
-
- return group->cpu_power;
+ return cpu_rq(cpu)->cpu_power;
}
static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
@@ -1854,8 +1841,8 @@
static void set_load_weight(struct task_struct *p)
{
if (task_has_rt_policy(p)) {
- p->se.load.weight = prio_to_weight[0] * 2;
- p->se.load.inv_weight = prio_to_wmult[0] >> 1;
+ p->se.load.weight = 0;
+ p->se.load.inv_weight = WMULT_CONST;
return;
}
@@ -7605,6 +7592,7 @@
#ifdef CONFIG_SMP
rq->sd = NULL;
rq->rd = NULL;
+ rq->cpu_power = SCHED_LOAD_SCALE;
rq->post_schedule = 0;
rq->active_balance = 0;
rq->next_balance = jiffies;