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| author | Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de> | 2011-07-20 14:46:59 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-07-21 18:01:55 +0200 |
| commit | 2bd2d6f2dc952fc44fc52887de36e51896da96b9 (patch) | |
| tree | 0b08e0ae13cad776cb216a4b85b1eb8d6eda6611 /kernel/sched_fair.c | |
| parent | acb5a9ba3bd7cd8b3264f67a3789a9587d3b935b (diff) | |
| download | lwn-2bd2d6f2dc952fc44fc52887de36e51896da96b9.tar.gz lwn-2bd2d6f2dc952fc44fc52887de36e51896da96b9.zip | |
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>
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | 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 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; |