diff options
authorStephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>2011-07-20 14:46:59 +0200
committerIngo Molnar <mingo@elte.hu>2011-07-21 18:01:55 +0200
commit2bd2d6f2dc952fc44fc52887de36e51896da96b9 (patch)
parentacb5a9ba3bd7cd8b3264f67a3789a9587d3b935b (diff)
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@tu-ilmenau.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-ns12mnd2h5w8rb9agd8hnsfk@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 files changed, 1 insertions, 7 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 0588c0b933a8..a2ecbaa28b4c 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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