sched: default to n for GROUP_SCHED and FAIR_GROUP_SCHED

GROUP_SCHED is confirmed to cause unacceptable latencies, see:

   http://lkml.org/lkml/2008/5/2/370.

Mark it EXPERIMENTAL and default to no for now.

Signed-off-by: Parag Warudkar <parag.warudkar@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/init/Kconfig b/init/Kconfig
index fa42e6b..4c33316 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -324,7 +324,8 @@
 
 config GROUP_SCHED
 	bool "Group CPU scheduler"
-	default y
+	depends on EXPERIMENTAL
+	default n
 	help
 	  This feature lets CPU scheduler recognize task groups and control CPU
 	  bandwidth allocation to such task groups.
@@ -332,7 +333,7 @@
 config FAIR_GROUP_SCHED
 	bool "Group scheduling for SCHED_OTHER"
 	depends on GROUP_SCHED
-	default y
+	default GROUP_SCHED
 
 config RT_GROUP_SCHED
 	bool "Group scheduling for SCHED_RR/FIFO"