From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <Ian.Campbell@citrix.com>
Subject: Re: [PATCHv2 net-next] xen-netback: remove
 unconditional __pskb_pull_tail() in guest Tx path
Date: Wed, 5 Nov 2014 10:58:58 +0000
Message-ID: <1415185138.11486.87.camel@citrix.com>
References: <1415184622-19421-1-git-send-email-david.vrabel@citrix.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta4.messagelabs.com ([85.158.143.247])
	by lists.xen.org with esmtp (Exim 4.72)
	(envelope-from <Ian.Campbell@citrix.com>) id 1XlyIp-0003cn-6b
	for xen-devel@lists.xenproject.org; Wed, 05 Nov 2014 10:59:03 +0000
In-Reply-To: <1415184622-19421-1-git-send-email-david.vrabel@citrix.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: David Vrabel <david.vrabel@citrix.com>
Cc: xen-devel@lists.xenproject.org, Malcolm Crossley <malcolm.crossley@citrix.com>, Paul Durrant <paul.durrant@citrix.com>, Wei Liu <wei.liu2@citrix.com>
List-Id: xen-devel@lists.xenproject.org

Dropping netdev since this isn't relevant to them, adding Paul

On Wed, 2014-11-05 at 10:50 +0000, David Vrabel wrote:
> - performance: Netback has already grant copied up-to 128 bytes from
>   the first slot of a packet into the linear area. The first slot
>   normally contain all the IPv4/IPv6 and TCP/UDP headers.

Does "normally" here include guests other than Linux? I thought Windows
in particular was prone to splitting the headers into a frag per layer
or thereabouts?

Ian.