Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-omap-h63xx.git] / kernel / sched_fair.c

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 8e1352c75557308bf1e892bb260b39e9feffd10f..5cc1c162044fc4f40b15c351cd170ce2c58703f7 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -283,7 +283,7 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
                                                   struct sched_entity,
                                                   run_node);
 
-               if (vruntime == cfs_rq->min_vruntime)
+               if (!cfs_rq->curr)
                        vruntime = se->vruntime;
                else
                        vruntime = min_vruntime(vruntime, se->vruntime);
@@ -429,7 +429,10 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
        u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq);
 
        for_each_sched_entity(se) {
-               struct load_weight *load = &cfs_rq->load;
+               struct load_weight *load;
+
+               cfs_rq = cfs_rq_of(se);
+               load = &cfs_rq->load;
 
                if (unlikely(!se->on_rq)) {
                        struct load_weight lw = cfs_rq->load;
@@ -677,9 +680,13 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
                        unsigned long thresh = sysctl_sched_latency;
 
                        /*
-                        * convert the sleeper threshold into virtual time
+                        * Convert the sleeper threshold into virtual time.
+                        * SCHED_IDLE is a special sub-class.  We care about
+                        * fairness only relative to other SCHED_IDLE tasks,
+                        * all of which have the same weight.
                         */
-                       if (sched_feat(NORMALIZED_SLEEPER))
+                       if (sched_feat(NORMALIZED_SLEEPER) &&
+                                       task_of(se)->policy != SCHED_IDLE)
                                thresh = calc_delta_fair(thresh, se);
 
                        vruntime -= thresh;
@@ -1340,14 +1347,18 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
 
 static void set_last_buddy(struct sched_entity *se)
 {
-       for_each_sched_entity(se)
-               cfs_rq_of(se)->last = se;
+       if (likely(task_of(se)->policy != SCHED_IDLE)) {
+               for_each_sched_entity(se)
+                       cfs_rq_of(se)->last = se;
+       }
 }
 
 static void set_next_buddy(struct sched_entity *se)
 {
-       for_each_sched_entity(se)
-               cfs_rq_of(se)->next = se;
+       if (likely(task_of(se)->policy != SCHED_IDLE)) {
+               for_each_sched_entity(se)
+                       cfs_rq_of(se)->next = se;
+       }
 }
 
 /*
@@ -1393,12 +1404,18 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
                return;
 
        /*
-        * Batch tasks do not preempt (their preemption is driven by
+        * Batch and idle tasks do not preempt (their preemption is driven by
         * the tick):
         */
-       if (unlikely(p->policy == SCHED_BATCH))
+       if (unlikely(p->policy != SCHED_NORMAL))
                return;
 
+       /* Idle tasks are by definition preempted by everybody. */
+       if (unlikely(curr->policy == SCHED_IDLE)) {
+               resched_task(curr);
+               return;
+       }
+
        if (!sched_feat(WAKEUP_PREEMPT))
                return;