Commit-ID: 2bd2d6f2dc952fc44fc52887de36e51896da96b9
Gitweb: http://git.kernel.org/tip/2bd2d6f2dc952fc44fc52887de36e51896da96b9
Author: Stephan Baerwolf <stephan.baerwolf@xxxxxxxxxxxxx>
AuthorDate: Wed, 20 Jul 2011 14:46:59 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 21 Jul 2011 18:01:55 +0200
sched: Replace use of entity_key()
"entity_key()" is only used in "__enqueue_entity()" and
its only function is to subtract a tasks vruntime by
its groups minvruntime.
Before this patch a rbtree enqueue-decision is done by
comparing two tasks in the style:
"if (entity_key(cfs_rq, se) < entity_key(cfs_rq, entry))"
which would be
"if (se->vruntime-cfs_rq->min_vruntime < entry->vruntime-cfs_rq->min_vruntime)"
or (if reducing cfs_rq->min_vruntime out)
"if (se->vruntime < entry->vruntime)"
which is
"if (entity_before(se, entry))"
So we do not need "entity_key()".
If "entity_before()" is inline we will also save one subtraction (only one,
because "entity_key(cfs_rq, se)" was cached in "key")
Signed-off-by: Stephan Baerwolf <stephan.baerwolf@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-ns12mnd2h5w8rb9agd8hnsfk@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/sched_fair.c | 8 +-------
1 files changed, 1 insertions(+), 7 deletions(-)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 0588c0b..a2ecbaa 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -321,11 +321,6 @@ static inline int entity_before(struct sched_entity *a,
return (s64)(a->vruntime - b->vruntime) < 0;
}
-static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
- return se->vruntime - cfs_rq->min_vruntime;
-}
-
static void update_min_vruntime(struct cfs_rq *cfs_rq)
{
u64 vruntime = cfs_rq->min_vruntime;
@@ -359,7 +354,6 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
struct rb_node *parent = NULL;
struct sched_entity *entry;
- s64 key = entity_key(cfs_rq, se);
int leftmost = 1;
/*
@@ -372,7 +366,7 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* We dont care about collisions. Nodes with
* the same key stay together.
*/
- if (key < entity_key(cfs_rq, entry)) {
+ if (entity_before(se, entry)) {
link = &parent->rb_left;
} else {
link = &parent->rb_right;
--
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