Re: [RFC 0/5] In virtio-spec 1.1, new feature bit VIRTIO_F_IN_ORDER was introduced.

From: Jason Wang <jasowang@redhat.com>
To: Guo Zhi <qtxuning1999@sjtu.edu.cn>
Cc: eperezma <eperezma@redhat.com>,
	Stefano Garzarella <sgarzare@redhat.com>, mst <mst@redhat.com>,
	netdev <netdev@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	kvm <kvm@vger.kernel.org>,
	virtualization <virtualization@lists.linux-foundation.org>
Subject: Re: [RFC 0/5] In virtio-spec 1.1, new feature bit VIRTIO_F_IN_ORDER was introduced.
Date: Thu, 21 Jul 2022 17:17:13 +0800	[thread overview]
Message-ID: <CACGkMEtvjy1_NYHOV=VKMWcggYnOUBk3PRue=t0Kd4wtHjfzQg@mail.gmail.com> (raw)
In-Reply-To: <20220721084341.24183-1-qtxuning1999@sjtu.edu.cn>

On Thu, Jul 21, 2022 at 4:44 PM Guo Zhi <qtxuning1999@sjtu.edu.cn> wrote:
>
> When this feature has been negotiated, virtio driver will use
> descriptors in ring order: starting from offset 0 in the table, and
> wrapping around at the end of the table. Vhost devices will always use
> descriptors in the same order in which they have been made available.
> This can reduce virtio accesses to used ring.
>
> Based on updated virtio-spec, this series realized IN_ORDER prototype
> in virtio driver and vhost.

Thanks a lot for the series.

I wonder if you can share any performance numbers for this?

Thanks

>
> Guo Zhi (5):
>   vhost: reorder used descriptors in a batch
>   vhost: announce VIRTIO_F_IN_ORDER support
>   vhost_test: batch used buffer
>   virtio: get desc id in order
>   virtio: annouce VIRTIO_F_IN_ORDER support
>
>  drivers/vhost/test.c         | 15 +++++++++++-
>  drivers/vhost/vhost.c        | 44 ++++++++++++++++++++++++++++++++++--
>  drivers/vhost/vhost.h        |  4 ++++
>  drivers/virtio/virtio_ring.c | 39 +++++++++++++++++++++++++-------
>  4 files changed, 91 insertions(+), 11 deletions(-)
>
> --
> 2.17.1
>