sched: fair-group scheduling vs latency

Currently FAIR_GROUP sched grows the scheduler latency outside of
sysctl_sched_latency, invert this so it stays within.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index b89fec9..9e301a2 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -362,29 +362,47 @@ static u64 __sched_period(unsigned long nr_running)
  */
 static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-       return calc_delta_mine(__sched_period(cfs_rq->nr_running),
-                              se->load.weight, &cfs_rq->load);
+       u64 slice = __sched_period(cfs_rq->nr_running);
+
+       for_each_sched_entity(se) {
+               cfs_rq = cfs_rq_of(se);
+
+               slice *= se->load.weight;
+               do_div(slice, cfs_rq->load.weight);
+       }
+
+
+       return slice;
 }
 
 /*
- * We calculate the vruntime slice.
+ * We calculate the vruntime slice of a to be inserted task
  *
  * vs = s/w = p/rw
  */
-static u64 __sched_vslice(unsigned long rq_weight, unsigned long nr_running)
+static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-       u64 vslice = __sched_period(nr_running);
+       unsigned long nr_running = cfs_rq->nr_running;
+       unsigned long weight;
+       u64 vslice;
 
-       vslice *= NICE_0_LOAD;
-       do_div(vslice, rq_weight);
+       if (!se->on_rq)
+               nr_running++;
 
-       return vslice;
-}
+       vslice = __sched_period(nr_running);
 
-static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-       return __sched_vslice(cfs_rq->load.weight + se->load.weight,
-                       cfs_rq->nr_running + 1);
+       for_each_sched_entity(se) {
+               cfs_rq = cfs_rq_of(se);
+
+               weight = cfs_rq->load.weight;
+               if (!se->on_rq)
+                       weight += se->load.weight;
+
+               vslice *= NICE_0_LOAD;
+               do_div(vslice, weight);
+       }
+
+       return vslice;
 }
 
 /*