Re: [PATCH 20/24] block: RCU free request_queue
From: Tejun Heo
Date: Wed Jan 02 2013 - 15:43:46 EST
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.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/