From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH net-next v5 07/10] forcedeth: implement ndo_get_stats64() API Date: Wed, 16 Nov 2011 19:32:47 +0000 Message-ID: <1321471967.2709.14.camel@bwh-desktop> References: <20111116085533.0982001e@s6510.linuxnetplumber.net> <1321463694.2709.1.camel@bwh-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , , , "David S. Miller" , Ian Campbell , Eric Dumazet , Jeff Kirsher , Jiri Pirko , Joe Perches , Szymon Janc , Richard Jones , Ayaz Abdulla To: David Decotigny Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2011-11-16 at 11:25 -0800, David Decotigny wrote: > Thanks for your feedback on these concerns. > > On Wed, Nov 16, 2011 at 9:14 AM, Ben Hutchings > wrote: > > On Wed, 2011-11-16 at 08:55 -0800, Stephen Hemminger wrote: > >> Or realize that the Tx side is single threaded by dev->xmit_lock already > >> and the Rx side is single threaded by NAPI. > > > > Right. > > Yes, that's what I meant by "Each software stat field is updated by > one single writer." in a previous email. However, I think that TX and > RX paths are not always synchronized. So I'm afraid that if I'm using > a single seqcount, I might run into trouble in the absence of a lock > around each update.... and I'd really prefer to avoid such a lock. Are > you suggesting I should use 2 independent seqcounts? One for RX path, > the other for TX path, all this without a lock around writers? Yes, there should be 1 for each path. Ben. -- Ben Hutchings, Staff 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.