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| author | Fabio Checconi <fabio@gandalf.sssup.it> | 2009-07-16 12:32:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-07-18 11:17:08 +0200 |
| commit | 54fdc5816631b43ba55fc3206d7add2d85850bc6 (patch) | |
| tree | 44aebd11ac53ef355b215d37f374fb40a4cb008b /kernel/sched_fair.c | |
| parent | 78af08d90b8f745044b1274430bc4bc6b2b27aca (diff) | |
| download | lwn-54fdc5816631b43ba55fc3206d7add2d85850bc6.tar.gz lwn-54fdc5816631b43ba55fc3206d7add2d85850bc6.zip | |
sched: Account for vruntime wrapping
I spotted two sites that didn't take vruntime wrap-around into
account. Fix these by creating a comparison helper that does do
so.
Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 7c248dc30f41..9ffb2b2ceba4 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -266,6 +266,12 @@ static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime) return min_vruntime; } +static inline int entity_before(struct sched_entity *a, + struct sched_entity *b) +{ + 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; @@ -1017,7 +1023,7 @@ static void yield_task_fair(struct rq *rq) /* * Already in the rightmost position? */ - if (unlikely(!rightmost || rightmost->vruntime < se->vruntime)) + if (unlikely(!rightmost || entity_before(rightmost, se))) return; /* @@ -1713,7 +1719,7 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) /* 'curr' will be NULL if the child belongs to a different group */ if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) && - curr && curr->vruntime < se->vruntime) { + curr && entity_before(curr, se)) { /* * Upon rescheduling, sched_class::put_prev_task() will place * 'current' within the tree based on its new key value. |