Messages in this thread Patch in this message | | | Date | Sun, 09 Mar 2008 18:09:07 +0100 | From | Peter Zijlstra <> | Subject | [RFC/PATCH 17/17] sched: fair: optimize the elegebility test |
| |
Suggested by Dmitry Adamushko; trade a div for a mult.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> --- kernel/sched_fair.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
Index: linux-2.6-2/kernel/sched_fair.c =================================================================== --- linux-2.6-2.orig/kernel/sched_fair.c +++ linux-2.6-2/kernel/sched_fair.c @@ -339,6 +339,12 @@ s64 avg_vruntime(struct cfs_root_rq *cfs } static inline +int avg_vruntime_cmp(struct cfs_root_rq *cfs_r_rq, s64 vruntime) +{ + return (vruntime * cfs_r_rq->nr_queued) <= cfs_r_rq->avg_vruntime; +} + +static inline s64 entity_deadline_key(struct cfs_root_rq *cfs_r_rq, struct sched_entity *se) { return se->vruntime + se->vperiod - cfs_r_rq->min_vruntime; @@ -430,11 +436,10 @@ static struct sched_entity *__pick_next_ */ static struct sched_entity *__pick_next_entity(struct cfs_root_rq *cfs_r_rq) { - struct sched_entity *next_deadline; - s64 avg = avg_vruntime(cfs_r_rq); + struct sched_entity *next_deadline = __pick_next_deadline(cfs_r_rq); + s64 vruntime = entity_timeline_key(cfs_r_rq, next_deadline); - next_deadline = __pick_next_deadline(cfs_r_rq); - if (entity_timeline_key(cfs_r_rq, next_deadline) <= avg) + if (avg_vruntime_cmp(cfs_r_rq, vruntime)) return next_deadline; return __pick_next_timeline(cfs_r_rq); --
| |