Re: [PATCH V2 3/4] blk-mq: fix dispatch from sw queue
From: Christoph Hellwig <hch@lst.de>
Date: 2018-12-17 11:09:00
On Mon, Dec 17, 2018 at 06:42:47PM +0800, Ming Lei wrote:
When requst is added to rq list of sw queue(ctx), the rq may be from different hctx, after multi queue mapping is introduced. So we have to put the request into one per-queue-type list inside sw queue, otherwise the request may be dispatched to wrong hw queue.
Hmm. For one I don't think splitting the lock makes sense even for split lists. Second, do we really need different lists, or just take the type into account when dispatching from rq_list? I'm not really sure about that one, but a rationale for splitting might be worth adding to the changelog if you want to stick to the split lists.