sched: Display autogroup names in /proc/sched_debug

Add autogroup name to cfs_rq and tasks information to /proc/sched_debug.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110111101257.GF4772@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_autogroup.c b/kernel/sched_autogroup.c
index 32a723b..938d52f 100644
--- a/kernel/sched_autogroup.c
+++ b/kernel/sched_autogroup.c
@@ -231,6 +231,11 @@
 #ifdef CONFIG_SCHED_DEBUG
 static inline int autogroup_path(struct task_group *tg, char *buf, int buflen)
 {
+	int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);
+
+	if (!enabled || !tg->autogroup)
+		return 0;
+
 	return snprintf(buf, buflen, "%s-%ld", "/autogroup", tg->autogroup->id);
 }
 #endif /* CONFIG_SCHED_DEBUG */
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 4d36f37..e4d3725 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -93,6 +93,9 @@
 
 static char *task_group_path(struct task_group *tg)
 {
+	if (autogroup_path(tg, group_path, PATH_MAX))
+		return group_path;
+
 	/*
 	 * May be NULL if the underlying cgroup isn't fully-created yet
 	 */