Messages in this thread | | | Date | Wed, 18 Apr 2012 14:42:55 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH 07/11] blkcg: make request_queue bypassing on allocation |
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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
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