On Wed, May 03, 2023 at 07:04:57AM +0200, Christoph Hellwig wrote: > On Mon, May 01, 2023 at 08:33:06AM -0700, Keith Busch wrote: > > From: Keith Busch <kbusch@xxxxxxxxxx> > > > > The cdev only services passthrough commands which don't merge, track > > stats, or need accounting. Give it a special request queue with all > > these options cleared so that we're not adding overhead for it. > > Why can't we always skip these for passthrough commands on any queue > with a little bit of core code? A special queue without a gendisk was a little easier to ensure it's not subscribed to any rq_qos features, iolatency, wbt, blkthrottle. We might be able to add more blk_rq_is_passthrough() for things we want to skip and get the same benefit. I'll look into it.
