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From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
	Stephen Hemminger <stephen@networkplumber.org>,
	dev@dpdk.org, qemu-devel@nongnu.org
Subject: Re: [dpdk-dev] [Qemu-devel] [PATCH 1/2] vhost: enable any layout feature
Date: Mon, 10 Oct 2016 11:50:28 +0800	[thread overview]
Message-ID: <20161010035028.GX1597@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <2889e609-f750-a4e1-66f8-768bb07a2339@redhat.com>

On Thu, Sep 29, 2016 at 10:05:22PM +0200, Maxime Coquelin wrote:
> >so doing this unconditionally would be a spec violation, but if you see
> >value in this, we can add a feature bit.
> Right it would be a spec violation, so it should be done conditionally.
> If a feature bit is to be added, what about VIRTIO_NET_F_NO_TX_HEADER?
> It would imply VIRTIO_NET_F_CSUM not set, and no GSO features set.
> If negotiated, we wouldn't need to prepend a header.

If we could skip Tx header, I think we could also skip Rx header, in the
case when mrg-rx is aslo turned off?

> From the micro-benchmarks results, we can expect +10% compared to
> indirect descriptors, and + 5% compared to using 2 descs in the
> virtqueue.
> Also, it should have the same benefits as indirect descriptors for 0%
> pkt loss (as we can fill 2x more packets in the virtqueue).
> 
> What do you think?

I would vote for this. It should yield maximum performance for the case
that it's guaranteed that packet size will always fit in a typical MTU
(1500).

	--yliu

  parent reply	other threads:[~2016-10-10  3:49 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-26  6:40 [dpdk-dev] [PATCH 0/2] enables vhost/virtio " Yuanhan Liu
2016-09-26  6:40 ` [dpdk-dev] [PATCH 1/2] vhost: enable " Yuanhan Liu
2016-09-26 18:01   ` Stephen Hemminger
2016-09-26 19:24     ` Michael S. Tsirkin
2016-09-27  3:11       ` Yuanhan Liu
2016-09-27 19:48         ` Stephen Hemminger
2016-09-27 19:56         ` Michael S. Tsirkin
2016-09-28  2:28           ` Yuanhan Liu
2016-09-29 15:30             ` [dpdk-dev] [Qemu-devel] " Maxime Coquelin
2016-09-29 17:57               ` Michael S. Tsirkin
2016-09-29 20:05                 ` Maxime Coquelin
2016-09-29 20:21                   ` Michael S. Tsirkin
2016-09-29 21:23                     ` Maxime Coquelin
2016-09-30 12:05                       ` Maxime Coquelin
2016-09-30 19:16                         ` Michael S. Tsirkin
2016-10-10  4:05                           ` Yuanhan Liu
2016-10-10  4:17                             ` Michael S. Tsirkin
2016-10-10  4:22                               ` Yuanhan Liu
2016-10-10  4:25                                 ` Michael S. Tsirkin
2016-10-10 12:40                                 ` Maxime Coquelin
2016-10-10 14:42                                   ` Yuanhan Liu
2016-10-10 14:54                                     ` Maxime Coquelin
2016-10-11  6:04                                       ` Yuanhan Liu
2016-10-11  6:39                                         ` Maxime Coquelin
2016-10-11  6:49                                           ` Yuanhan Liu
2016-10-03 14:20                     ` Maxime Coquelin
2016-10-10  3:37                     ` Yuanhan Liu
2016-10-10  3:46                       ` Michael S. Tsirkin
2016-10-10  3:59                         ` Yuanhan Liu
2016-10-10  4:16                           ` Wang, Zhihong
2016-10-10  4:24                             ` Michael S. Tsirkin
2016-10-10  4:39                             ` Michael S. Tsirkin
2016-10-11  6:57                               ` Yuanhan Liu
2016-10-12  3:21                                 ` Yuanhan Liu
     [not found]                                   ` <F5DF4F0E3AFEF648ADC1C3C33AD4DBF16C2409EB@SHSMSX101.ccr.corp.intel.com>
2016-10-13  2:52                                     ` Yang, Zhiyong
2016-10-10  3:50                   ` Yuanhan Liu [this message]
2016-10-09 23:20             ` [dpdk-dev] " Michael S. Tsirkin
2016-10-10  3:03               ` Yuanhan Liu
2016-10-10  3:04                 ` Michael S. Tsirkin
2016-10-10  3:10                   ` Yuanhan Liu
2016-09-26  6:40 ` [dpdk-dev] [PATCH 2/2] net/virtio: " Yuanhan Liu
2016-09-26 18:04   ` Stephen Hemminger
2016-09-29 18:00   ` Michael S. Tsirkin
2016-09-29 18:01     ` Michael S. Tsirkin
2016-11-10 15:18 ` [dpdk-dev] [PATCH 0/2] enables vhost/virtio " Michael S. Tsirkin

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