From d02e5ed8d55e2a2b2735232ea1da40ffbf4c0932 Mon Sep 17 00:00:00 2001
From: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Date: Mon, 15 Oct 2007 17:00:07 +0200
Subject: [PATCH] sched: sched_setscheduler() fix
Fix a problem in the 'sched-group' patch for !CONFIG_FAIR_GROUP_SCHED.
description:
sched_setscheduler()
{
...
if (task_running()) p->sched_class->put_prev_entity();
[ this one sets up cfs_rq->curr to NULL ]
...
if (task_running) p->sched_class->set_curr_task();
[ and this one is a _NOP_ (empty) for !CONFIG_FAIR_GROUP_SCHED ]
As a result, the task continues to run with cfs_rq->curr == NULL... no
crashes (due to checks for !NULL in place) but e.g. update_curr()
effectively becomes a NOP... i.e. runtime statistics for this task is
not accounted untill it's rescheduled anew.
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/sched_fair.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 12ab9338d563..144f3ef97380 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -984,6 +984,10 @@ static void set_curr_task_fair(struct rq *rq)
#else
static void set_curr_task_fair(struct rq *rq)
{
+ struct sched_entity *se = &rq->curr->se;
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+ cfs_rq->curr = se;
}
#endif