From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <shemminger@vyatta.com>
Subject: Re: [Question]About KVM network zero-copy  feature!
Date: Sat, 11 Aug 2012 13:55:56 -0700
Message-ID: <20120811135556.58ddf48d@nehalam.linuxnetplumber.net>
References: <50248148.4070204@huawei.com>
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To: "Peter Huang(Peng)" <peter.huangpeng@huawei.com>
Cc: kvm@vger.kernel.org, mst@redhat.com, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, avi@redhat.com
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On Fri, 10 Aug 2012 11:34:32 +0800
"Peter Huang(Peng)" <peter.huangpeng@huawei.com> wrote:

> Hi,All
> 
> I searched from git-log, and found that until now we have vhost TX zero-copy experiment feature, how
> about RX zero-copy?
> 
> For XEN, net-back also only has TX zero-copy, Is there any reason that RX zero-copy still not implemented?
> 
There is no guarantee that packet will ever be read by receiver. This means zero-copy could
create memory back pressure stalls.