[PATCH 07/11] blkcg: make request_queue bypassing on allocation

[Tejun Heo]

On Tue, Apr 17, 2012 at 04:04:58PM +0400, James Bottomley wrote:
> > So, the current code is technically correct although subtle like hell.
> > We can RCU defer blk_put_queue() from blk_cleanup_queue() using
> > call_rcu() to make clear that RCU grace period is necessary there.
> > Any better ideas?
> 
> Not really ... except that perhaps we might redo LUN scanning to use
> just a single queue, so repurpose the LUN underneath, but not destroy
> the old queue and setup the new one?  It's a bit counter intuitive, but
> it shouldn't be impossible.

I think we're fine as-is with comment explaining that there can't be
any active dereferencing going on by the time release is reached.

Thanks.

-- 
tejun