Re: [PATCH] doc: update virtio doc
From: Mcnamara, John <hidden>
Date: 2017-05-10 09:58:27
quoted hunk ↗ jump to hunk
-----Original Message----- From: Yang, Zhiyong Sent: Wednesday, May 10, 2017 7:18 AM To: dev@dpdk.org; Mcnamara, John <redacted> Cc: yuanhan.liu@linux.intel.com; maxime.coquelin@redhat.com; Yang, Zhiyong [off-list ref] Subject: [PATCH] doc: update virtio doc Add more explanations about vring size changes and virtio_header size. Signed-off-by: Zhiyong Yang <redacted> --- doc/guides/nics/virtio.rst | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)diff --git a/doc/guides/nics/virtio.rst b/doc/guides/nics/virtio.rst index91bedea..36ddd08 100644--- a/doc/guides/nics/virtio.rst +++ b/doc/guides/nics/virtio.rst@@ -41,8 +41,8 @@ The DPDK extends kni to support vhost raw socketinterface, which enables vhost to directly read/ write packets from/to a physical port. With this enhancement, virtio could achieve quite promising performance. -In future release, we will also make enhancement to vhost backend, - releasing peak performance of virtio PMD driver. +In future release, we will also make enhancement to vhost backend. +Peak performance of virtio PMD driver will be released with every release version since DPDK 17.02 release.
Hi, There have been great performance improvements in Virtio in the last few releases. However, we can't really promise that is will improve in every release. I'd suggest removing these two lines and the previous line starting with "With this enhancement, virtio could ...".
... -* RTE_PKTMBUF_HEADROOM should be defined larger than sizeof(struct virtio_net_hdr), which is 10 bytes. +* RTE_PKTMBUF_HEADROOM should be defined + larger than sizeof(struct virtio_net_hdr), which is 10 bytes, when using non-mergeable. + larger than sizeof(struct virtio_net_hdr_mrg_rxbuf), which is 12 bytes when mergeable or F_VERSION_1 + is set.
All constants and struct names should be ```` quoted. Like this:
* ``RTE_PKTMBUF_HEADROOM`` should be defined larger than
``sizeof(struct virtio_net_hdr)``, which is 10 bytes, when using
non-mergeable or larger than ``sizeof(struct virtio_net_hdr_mrg_rxbuf)``,
which is 12 bytes when mergeable or ``F_VERSION_1`` is set.
John