[PATCH 2/6] sched: rt-bandwidth accounting fix

Peter Zijlstra
2008-08-19T10:46:16Z

[-- Attachment #1: sched-rt-bw-fix-accounting.patch --]
[-- Type: text/plain, Size: 1186 bytes --]

It fixes an accounting bug where we would continue accumulating runtime
even though the bandwidth control is disabled. This would lead to very long
throttle periods once bandwidth control gets turned on again.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/sched_rt.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

Index: linux-2.6/kernel/sched_rt.c
===================================================================
--- linux-2.6.orig/kernel/sched_rt.c
+++ linux-2.6/kernel/sched_rt.c
@@ -438,9 +438,6 @@ static int sched_rt_runtime_exceeded(str
{
u64 runtime = sched_rt_runtime(rt_rq);

- if (runtime == RUNTIME_INF)
- return 0;
-
if (rt_rq->rt_throttled)
return rt_rq_throttled(rt_rq);

@@ -491,9 +488,11 @@ static void update_curr_rt(struct rq *rq
rt_rq = rt_rq_of_se(rt_se);

spin_lock(&rt_rq->rt_runtime_lock);
- rt_rq->rt_time += delta_exec;
- if (sched_rt_runtime_exceeded(rt_rq))
- resched_task(curr);
+ if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
+ rt_rq->rt_time += delta_exec;
+ if (sched_rt_runtime_exceeded(rt_rq))
+ resched_task(curr);
+ }
spin_unlock(&rt_rq->rt_runtime_lock);
}
}

--