[34-longterm 084/247] sched: Move sched_avg_update() to update_cpu_load()

From: Paul Gortmaker
Date: Thu Jun 23 2011 - 14:19:39 EST


From: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit da2b71edd8a7db44fe1746261410a981f3e03632 upstream.

Currently sched_avg_update() (which updates rt_avg stats in the rq)
is getting called from scale_rt_power() (in the load balance context)
which doesn't take rq->lock.

Fix it by moving the sched_avg_update() to more appropriate
update_cpu_load() where the CFS load gets updated as well.

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <1282596171.2694.3.camel@sbsiddha-MOBL3>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
kernel/sched.c | 6 ++++++
kernel/sched_fair.c | 2 --
2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 12ee156..c3e891f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1269,6 +1269,10 @@ static void resched_task(struct task_struct *p)
static void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
{
}
+
+static void sched_avg_update(struct rq *rq)
+{
+}
#endif /* CONFIG_SMP */

#if BITS_PER_LONG == 32
@@ -3102,6 +3106,8 @@ static void update_cpu_load(struct rq *this_rq)
this_rq->calc_load_update += LOAD_FREQ;
calc_load_account_active(this_rq);
}
+
+ sched_avg_update(this_rq);
}

#ifdef CONFIG_SMP
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 72eb9a6..3a0f7ba 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -2337,8 +2337,6 @@ unsigned long scale_rt_power(int cpu)
struct rq *rq = cpu_rq(cpu);
u64 total, available;

- sched_avg_update(rq);
-
total = sched_avg_period() + (rq->clock - rq->age_stamp);
available = total - rq->rt_avg;

--
1.7.4.4

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