Re: [PATCH 2/2] virtio_ring: add unlikely annotation for free descs check

[Xianting Tian]

I can't find it in next branch, will you apply this patch?

在 2022/3/29 下午3:50, Stefano Garzarella 写道:
> On Mon, Mar 28, 2022 at 06:58:17PM +0800, Xianting Tian wrote:
> > The 'if (vq->vq.num_free < descs_used)' check will almost always be 
> > false.
> >
> > Signed-off-by: Xianting Tian <xianting.tian@xxxxxxxxxxxxxxxxx>
> > ---
> > drivers/virtio/virtio_ring.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
>
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index d597fc0874ec..ab6d5f0cb579 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -525,7 +525,7 @@ static inline int virtqueue_add_split(struct 
> > virtqueue *_vq,
> >         descs_used = total_sg;
> >     }
> >
> > -    if (vq->vq.num_free < descs_used) {
> > +    if (unlikely(vq->vq.num_free < descs_used)) {
> >         pr_debug("Can't add buf len %i - avail = %i\n",
> >              descs_used, vq->vq.num_free);
> >         /* FIXME: for historical reasons, we force a notify here if
> > --
> > 2.17.1