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authorPeter Zijlstra <peterz@infradead.org>2008-11-11 11:52:33 +0100
committerIngo Molnar <mingo@elte.hu>2008-11-11 11:57:22 +0100
commit2002c69595a092518107f7e3c1294c9710bc92ae (patch)
tree5935add4d4cd426b5b824474b7ec2ffea48d2951
parentad474caca3e2a0550b7ce0706527ad5ab389a4d4 (diff)
downloadlinux-2.6.38-lt-ux500-2002c69595a092518107f7e3c1294c9710bc92ae.tar.gz
sched: release buddies on yield
Clear buddies on yield, so that the buddy rules don't schedule them despite them being placed right-most. This fixed a performance regression with yield-happy binary JVMs. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Lin Ming <ming.m.lin@intel.com>
-rw-r--r--kernel/sched_fair.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 51aa3e102ac..98345e45b05 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -716,6 +716,15 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
__enqueue_entity(cfs_rq, se);
}
+static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ if (cfs_rq->last == se)
+ cfs_rq->last = NULL;
+
+ if (cfs_rq->next == se)
+ cfs_rq->next = NULL;
+}
+
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
{
@@ -738,11 +747,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
#endif
}
- if (cfs_rq->last == se)
- cfs_rq->last = NULL;
-
- if (cfs_rq->next == se)
- cfs_rq->next = NULL;
+ clear_buddies(cfs_rq, se);
if (se != cfs_rq->curr)
__dequeue_entity(cfs_rq, se);
@@ -977,6 +982,8 @@ static void yield_task_fair(struct rq *rq)
if (unlikely(cfs_rq->nr_running == 1))
return;
+ clear_buddies(cfs_rq, se);
+
if (likely(!sysctl_sched_compat_yield) && curr->policy != SCHED_BATCH) {
update_rq_clock(rq);
/*