blkio: Some debugging aids for CFQ

o Some debugging aids for CFQ.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0426ab692fd5..6bc99a3865b0 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -33,6 +33,10 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
         blkg->blkcg_id = css_id(&blkcg->css);
         hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
         spin_unlock_irqrestore(&blkcg->lock, flags);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+        /* Need to take css reference ? */
+        cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
+#endif
 }
 
 static void __blkiocg_del_blkio_group(struct blkio_group *blkg)