From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [GIT/PATCH v4] xen network backend driver Date: Thu, 10 Mar 2011 17:30:13 +0000 Message-ID: <1299778213.2807.11.camel@bwh-desktop> References: <1299776554.17339.824.camel@zakaz.uk.xensource.com> <20110310091555.0fa8764d@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Ian Campbell , "netdev@vger.kernel.org" , xen-devel , Jeremy Fitzhardinge , Herbert Xu , Konrad Rzeszutek Wilk , Francois Romieu To: Stephen Hemminger Return-path: Received: from mail.solarflare.com ([216.237.3.220]:36081 "EHLO exchange.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753461Ab1CJRaR (ORCPT ); Thu, 10 Mar 2011 12:30:17 -0500 In-Reply-To: <20110310091555.0fa8764d@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2011-03-10 at 09:15 -0800, Stephen Hemminger wrote: > On Thu, 10 Mar 2011 17:02:33 +0000 > Ian Campbell wrote: > > +struct xenvif { > > + /* Unique identifier for this interface. */ > ... > > + struct net_device_stats stats; > > + > > There is already a stats struct in net_device in current kernel > versions, unless there is a compelling reason otherwise > please use that. > > Also, you probably want to implement per-cpu and 64 bit > stats. The driver is using a single queue, so I don't see what benefit it would get from per-cpu stats. At some point it should become multiqueue and then it should store per-queue stats. 64-bit stats are definitely preferable, but since they're being maintained on the data path this may require some significant work. (Ian: see for the canonical way to do this.) Given that only a relatively few existing drivers do this (I count 13), I'm not sure we can reasonably demand that a new driver does - yet. Ben. -- Ben Hutchings, Senior Software Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.