GROUP_SCHED is confirmed to cause unacceptable latencies -
http://lkml.org/lkml/2008/5/2/370. 

Besides there is no reason for it to be on by default.

Mark it EXPERIMENTAL and default to no.

Signed-off-by: Parag Warudkar <parag.warudkar@gmail.com>

--- linux-2.6/init/Kconfig.orig	2008-05-03 20:14:41.000000000 -0400
+++ linux-2.6/init/Kconfig	2008-05-03 20:29:06.000000000 -0400
@@ -318,7 +318,8 @@
 
 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.
@@ -326,7 +327,7 @@
 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"