[patch] sched: fix unregister_fair_sched_group

[Paul Turner <pjt@google.com>]

[-- Attachment #1: sched-fix_unregister.patch --]
[-- Type: text/plain, Size: 1069 bytes --]

In the flipping and flopping between calling unregister_fair_sched_group on a
per-cpu versus per-group basis we ended up in a bad state.

Remove from the list for the passed cpu as opposed to some arbitrary index.

(This fixes explosions w/ autogroup as well as a group creation/destruction 
stress test)

Signed-off-by: Paul Turner <pjt@google.com>
---
 kernel/sched.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Index: tip/kernel/sched.c
===================================================================
--- tip.orig/kernel/sched.c
+++ tip/kernel/sched.c
@@ -8097,7 +8097,6 @@ static inline void unregister_fair_sched
 {
 	struct rq *rq = cpu_rq(cpu);
 	unsigned long flags;
-	int i;
 
 	/*
 	* Only empty task groups can be destroyed; so we can speculatively
@@ -8107,7 +8106,7 @@ static inline void unregister_fair_sched
 		return;
 
 	raw_spin_lock_irqsave(&rq->lock, flags);
-	list_del_leaf_cfs_rq(tg->cfs_rq[i]);
+	list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
 	raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 #else /* !CONFG_FAIR_GROUP_SCHED */