[tip:sched/core] sched: Don't call task_group() too many times in set_task_rq()

[tip-bot for Andrew Vagin <avagin@openvz.org>]

Commit-ID:  a3e5d1091c1298ded486aba87c22fe90cb55ea6c
Gitweb:     http://git.kernel.org/tip/a3e5d1091c1298ded486aba87c22fe90cb55ea6c
Author:     Andrew Vagin <avagin@openvz.org>
AuthorDate: Fri, 11 Nov 2011 17:04:00 +0300
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 16 Nov 2011 08:48:24 +0100

sched: Don't call task_group() too many times in set_task_rq()

It improves perfomance, especially if autogroup is enabled.

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

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1321020240-3874331-1-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/sched.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 0df6986..c9e3ab6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -793,14 +793,18 @@ 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
 }