h63xx: nfs mount works, gpe image boots to ts config screen.

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

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index ce514afd78ff7998338b6661ae22475e808fa3fa..98345e45b059ac665e13ce534a6fbb8a3460c5cf 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -341,23 +341,20 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
                cfs_rq->rb_leftmost = next_node;
        }
 
-       if (cfs_rq->next == se)
-               cfs_rq->next = NULL;
-
        rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
 }
 
-static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq)
-{
-       return cfs_rq->rb_leftmost;
-}
-
 static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq)
 {
-       return rb_entry(first_fair(cfs_rq), struct sched_entity, run_node);
+       struct rb_node *left = cfs_rq->rb_leftmost;
+
+       if (!left)
+               return NULL;
+
+       return rb_entry(left, struct sched_entity, run_node);
 }
 
-static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
+static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 {
        struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
 
@@ -719,6 +716,15 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
                __enqueue_entity(cfs_rq, se);
 }
 
+static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+       if (cfs_rq->last == se)
+               cfs_rq->last = NULL;
+
+       if (cfs_rq->next == se)
+               cfs_rq->next = NULL;
+}
+
 static void
 dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
 {
@@ -741,6 +747,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
 #endif
        }
 
+       clear_buddies(cfs_rq, se);
+
        if (se != cfs_rq->curr)
                __dequeue_entity(cfs_rq, se);
        account_entity_dequeue(cfs_rq, se);
@@ -794,24 +802,15 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 static int
 wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
 
-static struct sched_entity *
-pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-       if (!cfs_rq->next || wakeup_preempt_entity(cfs_rq->next, se) == 1)
-               return se;
-
-       return cfs_rq->next;
-}
-
 static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
 {
-       struct sched_entity *se = NULL;
+       struct sched_entity *se = __pick_next_entity(cfs_rq);
 
-       if (first_fair(cfs_rq)) {
-               se = __pick_next_entity(cfs_rq);
-               se = pick_next(cfs_rq, se);
-               set_next_entity(cfs_rq, se);
-       }
+       if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, se) < 1)
+               return cfs_rq->next;
+
+       if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, se) < 1)
+               return cfs_rq->last;
 
        return se;
 }
@@ -983,6 +982,8 @@ static void yield_task_fair(struct rq *rq)
        if (unlikely(cfs_rq->nr_running == 1))
                return;
 
+       clear_buddies(cfs_rq, se);
+
        if (likely(!sysctl_sched_compat_yield) && curr->policy != SCHED_BATCH) {
                update_rq_clock(rq);
                /*
@@ -1325,26 +1326,53 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
        return 0;
 }
 
+static void set_last_buddy(struct sched_entity *se)
+{
+       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;
+}
+
 /*
  * Preempt the current task with a newly woken task if needed:
  */
 static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
 {
        struct task_struct *curr = rq->curr;
-       struct cfs_rq *cfs_rq = task_cfs_rq(curr);
        struct sched_entity *se = &curr->se, *pse = &p->se;
 
        if (unlikely(rt_prio(p->prio))) {
+               struct cfs_rq *cfs_rq = task_cfs_rq(curr);
+
                update_rq_clock(rq);
                update_curr(cfs_rq);
                resched_task(curr);
                return;
        }
 
+       if (unlikely(p->sched_class != &fair_sched_class))
+               return;
+
        if (unlikely(se == pse))
                return;
 
-       cfs_rq_of(pse)->next = pse;
+       /*
+        * Only set the backward buddy when the current task is still on the
+        * rq. This can happen when a wakeup gets interleaved with schedule on
+        * the ->pre_schedule() or idle_balance() point, either of which can
+        * drop the rq lock.
+        *
+        * Also, during early boot the idle thread is in the fair class, for
+        * obvious reasons its a bad idea to schedule back to the idle thread.
+        */
+       if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle))
+               set_last_buddy(se);
+       set_next_buddy(pse);
 
        /*
         * We can come here with TIF_NEED_RESCHED already set from new task
@@ -1396,6 +1424,7 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
 
        do {
                se = pick_next_entity(cfs_rq);
+               set_next_entity(cfs_rq, se);
                cfs_rq = group_cfs_rq(se);
        } while (cfs_rq);