Re: [PATCH v5 1/2] virtio-blk: support polling I/O

[Suwan Kim <suwan.kim027@gmail.com>]

On Tue, Apr 05, 2022 at 10:00:29PM -0700, Christoph Hellwig wrote:
> On Wed, Apr 06, 2022 at 12:09:23AM +0900, Suwan Kim wrote:
> > +        for (i = 0; i < num_vqs - num_poll_vqs; i++) {
> > +                callbacks[i] = virtblk_done;
> > +                snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
> > +                names[i] = vblk->vqs[i].name;
> > +        }
> > +
> > +        for (; i < num_vqs; i++) {
> > +                callbacks[i] = NULL;
> > +                snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
> > +                names[i] = vblk->vqs[i].name;
> > +        }
> 
> This uses spaces for indentation.

Oh my mistake. I will fix it.

> > +		/*
> > +		 * Regular queues have interrupts and hence CPU affinity is
> > +		 * defined by the core virtio code, but polling queues have
> > +		 * no interrupts so we let the block layer assign CPU affinity.
> > +		 */
> > +		if (i != HCTX_TYPE_POLL)
> > +			blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0);
> > +		else
> > +			blk_mq_map_queues(&set->map[i]);
> 
> Nit, but I would have just done a "positive" check here as that is ab it
> easier to read:
> 
> 		if (i == HCTX_TYPE_POLL)
> 			blk_mq_map_queues(&set->map[i]);
> 		else
> 			blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0);

I agree. I will fix it.
Thanks for the feedback!

Regards,
Suwan Kim

>
> Otherwise looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>