[PATCH] sched: don't call task_group() many times in set_task_rq()

Andrew Vagin
2011-11-11T14:03:47Z

It improves perfomance, especially if autogroup enabled.

The size of set_task_rq() was 0x180 and now it is 0xa0.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
---
kernel/sched.c | 12 ++++++++----
1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index d87c6e5..a740eec 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -766,14 +766,18 @@ static inline struct task_group *task_group(struct task_struct *p)
/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
{
+#if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
+ struct task_group *tg = task_group(p);
+#endif
+
#ifdef CONFIG_FAIR_GROUP_SCHED
- p->se.cfs_rq = task_group(p)->cfs_rq[cpu];
- p->se.parent = task_group(p)->se[cpu];
+ p->se.cfs_rq = tg->cfs_rq[cpu];
+ p->se.parent = tg->se[cpu];
#endif

#ifdef CONFIG_RT_GROUP_SCHED
- p->rt.rt_rq = task_group(p)->rt_rq[cpu];
- p->rt.parent = task_group(p)->rt_se[cpu];
+ p->rt.rt_rq = tg->rt_rq[cpu];
+ p->rt.parent = tg->rt_se[cpu];
#endif
}

--
1.7.1