From mboxrd@z Thu Jan  1 00:00:00 1970
From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Subject: Re: [PATCH v2] virtio: use zeroed memory for simple TX
 header
Date: Tue, 5 Apr 2016 12:26:54 +0800
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Cc: Rich Lane <rich.lane@bigswitch.com>, dev@dpdk.org,
 Huawei Xie <huawei.xie@intel.com>,
 Stephen Hemminger <stephen@networkplumber.org>
To: "Tan, Jianfeng" <jianfeng.tan@intel.com>
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On Tue, Apr 05, 2016 at 11:20:05AM +0800, Tan, Jianfeng wrote:
> Hi,
> 
> On 4/5/2016 10:11 AM, Rich Lane wrote:
> >For simple TX the virtio-net header must be zeroed, but it was using memory
> >that had been initialized with indirect descriptor tables. This resulted in
> >"unsupported gso type" errors from librte_vhost.
> >
> >We can use the same memory for every descriptor to save cachelines in the
> >vswitch.
> 
> Pointing all virtio_net_hdr into the same memory may brings performance, but
> how much? It also introduces difficulty to adding tso in future?

simple rxtx will not be enabled when TSO is enabled.

	--yliu