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

[Maxime Coquelin <maxime.coquelin@redhat.com>]

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.

>   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(-)
>