On Thu, Dec 9, 2021 at 10:34 AM Or Ozeri <o...@il.ibm.com> wrote:
>
> The blk_get_max_hw_transfer API was recently added in 6.1.0.
> It allows querying an underlying block device its max transfer capability.
> This commit changes virtio-blk to use this.
>
> Signed-off-by: Or Ozeri <o...@il.ibm.com>
> ---
> hw/block/virtio-blk.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index f139cd7cc9..1ba9a06888 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -458,7 +458,7 @@ static void virtio_blk_submit_multireq(BlockBackend *blk,
> MultiReqBuffer *mrb)
> return;
> }
>
> - max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk);
> + max_transfer = blk_get_max_hw_transfer(mrb->reqs[0]->dev->blk);
>
> qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs),
> &multireq_compare);
> --
> 2.25.1
>
>
Hi Or,
Superficially, this makes sense to me. A couple of things to consider:
- Move the explanation from the cover letter into the patch
description. The current patch description is pretty much
meaningless.
- Should the actual limit be consulted for the number of segments
as well? IOW should blk_get_max_hw_iov() be called instead of
blk_get_max_iov() a dozen lines below?
I'm adding Stefan and Kevin to CC to get more eyes on this patch as it
fixes a regression. I believe this was encountered with the following
NBD device, Or please correct me if I'm wrong:
$ cat /sys/block/nbd0/queue/max_sectors_kb
128
$ cat /sys/block/nbd0/queue/max_segments
65535
Thanks,
Ilya
