[patch 0/4] [RFC] Another proportional weight IO controller

[Fabio Checconi]

> From: Vivek Goyal <vgoyal at redhat.com>
> Date: Thu, Nov 20, 2008 04:31:55PM -0500
>
...
> Hi Fabio,
> 
> I though will give bfq a try.  I get following when I put my current shell
> into a newly created cgroup and then try to do "ls".
> 

The posted patch cannot work as it is, I'm sorry for that ugly bug.
Do you still have problems with this one applied?

---
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index efb03fc..ed8c597 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -168,7 +168,7 @@ static void bfq_group_chain_link(struct bfq_data *bfqd, struct cgroup *cgroup,
 
 		spin_lock_irqsave(&bgrp->lock, flags);
 
-		rcu_assign_pointer(bfqg->bfqd, bfqd);
+		rcu_assign_pointer(leaf->bfqd, bfqd);
 		hlist_add_head_rcu(&leaf->group_node, &bgrp->group_data);
 		hlist_add_head(&leaf->bfqd_node, &bfqd->group_list);