sched: yield fix
fix yield bugs due to the current-not-in-rbtree changes: the task is
not in the rbtree so rbtree-removal is a no-no.
[ From: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>: build fix. ]
also, nice code size reduction:
kernel/sched.o:
text data bss dec hex filename
38323 3506 24 41853 a37d sched.o.before
38236 3506 24 41766 a326 sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5384a97..fcd6900 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -739,9 +739,7 @@
static void yield_task_fair(struct rq *rq)
{
struct cfs_rq *cfs_rq = task_cfs_rq(rq->curr);
- struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
struct sched_entity *rightmost, *se = &rq->curr->se;
- struct rb_node *parent;
/*
* Are we the only task in the tree?
@@ -755,39 +753,26 @@
* Dequeue and enqueue the task to update its
* position within the tree:
*/
- dequeue_entity(cfs_rq, se, 0);
- enqueue_entity(cfs_rq, se, 0);
+ update_curr(cfs_rq);
return;
}
/*
* Find the rightmost entry in the rbtree:
*/
- do {
- parent = *link;
- link = &parent->rb_right;
- } while (*link);
-
- rightmost = rb_entry(parent, struct sched_entity, run_node);
+ rightmost = __pick_last_entity(cfs_rq);
/*
* Already in the rightmost position?
*/
- if (unlikely(rightmost == se))
+ if (unlikely(rightmost->vruntime < se->vruntime))
return;
/*
* Minimally necessary key value to be last in the tree:
+ * Upon rescheduling, sched_class::put_prev_task() will place
+ * 'current' within the tree based on its new key value.
*/
se->vruntime = rightmost->vruntime + 1;
-
- if (cfs_rq->rb_leftmost == &se->run_node)
- cfs_rq->rb_leftmost = rb_next(&se->run_node);
- /*
- * Relink the task to the rightmost position:
- */
- rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
- rb_link_node(&se->run_node, parent, link);
- rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
}
/*
