Re: [dpdk-dev] [PATCH v2 0/8] support VIRTIO_F_IN_ORDER feature

["Liu, Yong" <yong.liu@intel.com>]

> -----Original Message-----
> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
> Sent: Tuesday, June 26, 2018 3:56 PM
> To: Liu, Yong <yong.liu@intel.com>; Bie, Tiwei <tiwei.bie@intel.com>
> Cc: Wang, Zhihong <zhihong.wang@intel.com>; dev@dpdk.org
> Subject: Re: [PATCH v2 0/8] support VIRTIO_F_IN_ORDER feature
> 
> Hi,
> 
> On 06/25/2018 05:17 PM, Marvin Liu wrote:
> > In latest virtio-spec, new feature bit VIRTIO_F_IN_ORDER was introduced.
> > 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. Due to new [RT]x path added into selection, also add
> > two new parameters mrg_rx and in_order into virtio-user vdev parameters
> > list. This will allow user to configure feature bits thus can impact
> > [RT]x path selection.
> >
> > Performance of virtio user with IN_ORDER feature:
> >
> >      Platform: Purely
> >      CPU: Intel(R) Xeon(R) Platinum 8160 CPU @ 2.10GHz
> >      DPDK baseline: 18.05
> >      Setup: testpmd with vhost vdev + testpmd with virtio vdev
> >
> >      +--------------+----------+----------+---------+
> >      |Vhost->Virtio |1 Queue   |2 Queues  |4 Queues |
> >      +--------------+----------+----------+---------+
> >      |Inorder       |12.0Mpps  |24.2Mpps  |26.0Mpps |
> >      |Normal        |12.1Mpps  |18.5Mpps  |18.9Mpps |
> >      +--------------+----------+----------+---------+
> >
> >      +--------------+----------+----------------+---------+
> >      |Virtio->Vhost |1 Queue   |2 Queues        |4 Queues |
> >      +--------------+----------+----------------+---------+
> >      |Inorder       |13.8Mpps  |10.7 ~ 15.2Mpps |11.5Mpps |
> >      |Normal        |13.3Mpps  |9.8 ~ 14Mpps    |10.5Mpps |
> >      +--------------+----------+----------------+---------+
> >
> >      +---------+----------+----------------+----------------+
> >      |Loopback |1 Queue   |2 Queues        |4 Queues        |
> >      +---------+----------+----------------+----------------+
> >      |Inorder  |7.4Mpps   |9.1 ~ 11.6Mpps  |10.5 ~ 11.3Mpps |
> >      +---------+----------+----------------+----------------+
> >      |Normal   |7.5Mpps   |7.7 ~ 9.0Mpps   |7.6 ~ 7.8Mpps   |
> >      +---------+----------+----------------+----------------+
> >
> > v2:
> > - merge to latest dpdk-net-virtio
> > - not use in_direct for normal xmit packets
> > - update available ring for each descriptor
> > - clean up IN_ORDER xmit function
> > - unmask feature bits when disabled in_order or mgr_rxbuf
> > - extract common part between IN_ORDER and normal functions
> > - update performance result
> >
> > Marvin Liu (8):
> >    vhost: announce VIRTIO_F_IN_ORDER support
> >    net/virtio: add VIRTIO_F_IN_ORDER definition
> >    net/virtio-user: add mrg_rxbuf and in_order vdev parameters
> >    net/virtio: free IN_ORDER descriptors before device start
> >    net/virtio: extract common part for IN_ORDER functions
> >    net/virtio: support IN_ORDER Rx and Tx
> >    net/virtio: add IN_ORDER Rx/Tx into selection
> >    net/virtio: annouce VIRTIO_F_IN_ORDER support
> 
> I haven't checked but guess the titles doesn't pass the check-git-log.sh
> script as they contains underscores.

Thanks for your reminder, Maxime. I will replace "IN_ORDER" to "in order" which can pass check.
> 
> >   drivers/net/virtio/virtio_ethdev.c            |  31 +-
> >   drivers/net/virtio/virtio_ethdev.h            |   7 +
> >   drivers/net/virtio/virtio_pci.h               |   8 +
> >   drivers/net/virtio/virtio_rxtx.c              | 635 ++++++++++++++++--
> >   .../net/virtio/virtio_user/virtio_user_dev.c  |  14 +-
> >   .../net/virtio/virtio_user/virtio_user_dev.h  |   3 +-
> >   drivers/net/virtio/virtio_user_ethdev.c       |  33 +-
> >   drivers/net/virtio/virtqueue.c                |   8 +
> >   drivers/net/virtio/virtqueue.h                |   2 +
> >   lib/librte_vhost/socket.c                     |   6 +
> >   lib/librte_vhost/vhost.h                      |  10 +-
> >   11 files changed, 688 insertions(+), 69 deletions(-)
> >