Messages in this thread |  | | Date | Wed, 2 Jan 2013 15:43:55 -0500 | From | Tejun Heo <> | Subject | Re: [PATCH 20/24] block: RCU free request_queue |
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On Wed, Jan 02, 2013 at 01:48:15PM -0500, Vivek Goyal wrote: > On Fri, Dec 28, 2012 at 12:35:42PM -0800, Tejun Heo wrote: > > RCU free request_queue so that blkcg_gq->q can be dereferenced under > > RCU lock. This will be used to implement hierarchical stats. > > Can we just take a blkg reference on ->q in blkg_alloc() and drop that > reference in blkg_free(), instead of RCU freeing up queue.
I don't think we can invoke blk_release_queue() from RCU free contxt, so we can't put request_queue from blkg_rcu_free(). Maybe we can go through a work item but that's uglier.
Thanks.
-- tejun
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