Re: [RFC PATCH] blk-mq: hctx has only one ctx mapping is no need to redirect the completion

From: Christoph Hellwig
Date: Thu Sep 22 2022 - 02:20:34 EST


On Wed, Sep 21, 2022 at 11:32:03AM +0800, Liu Song wrote:
> From: Liu Song <liusong@xxxxxxxxxxxxxxxxx>
>
> High-performance NVMe devices usually support a large hw queue, which

a larger number of?

> /*
> - * For a polled request, always complete locally, it's pointless
> - * to redirect the completion.
> + * For request which hctx has only one ctx mapping,
> + * or a polled request, always complete locally,
> + * it's pointless to redirect the completion.
> */
> - if (rq->cmd_flags & REQ_POLLED)
> + if (rq->mq_hctx->nr_ctx == 1 ||
> + rq->cmd_flags & REQ_POLLED)

Some very odd comment formatting and and indentation here.