From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Dangaard Brouer Subject: Re: [PATCH] igb: Record hardware RX overruns in net_stats Date: Wed, 06 May 2009 10:12:42 +0200 Message-ID: <1241597562.5172.25.camel@localhost.localdomain> References: <1241435206.8115.104.camel@localhost.localdomain> <9929d2390905051147y71f34e4bu9f63edc1e5a253a2@mail.gmail.com> <20090505.115819.84151021.davem@davemloft.net> <273D38FBE7C6FE46A1689FCD014A0B8B49655903@azsmsx505.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Jesper Dangaard Brouer , "e1000-devel@lists.sourceforge.net" , netdev , "Waskiewicz Jr, Peter P" , "Allan, Bruce W" , "Brandeburg, Jesse" , "Kirsher, Jeffrey T" , David Miller To: "Ronciak, John" Return-path: In-Reply-To: <273D38FBE7C6FE46A1689FCD014A0B8B49655903@azsmsx505.amr.corp.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On Tue, 2009-05-05 at 15:38 -0700, Ronciak, John wrote: > >Its really useful for diagnosing problems, and I'm betting > >that this is a real-life situation which people is going to experience. We > >might as well help our self to more easily identify this issue when people > >report drop problems. > > The problem is that the RNBC aren't dropped packets as the numbers you > have show. Just to make it clear, I am experiencing dropped packets. The reason I positivly know this, is that I'm writing a MPEG2-TS drop detection netfilter module. Which were the only reason I discovered the packet drops and the "hidden" RNBC counter via ethtool. I have read the datasheeet, and with Jeffrey's detailed explaination, I do know that this number might be higher than the actually drops I'm experiencing. > While we can agree that the MPC are the actual dropped packets and > could eaily be be used in the fifo overflow count since the packets > were really dropped. Well, then I think we should keep MPC as drops, and use the fifo_errors as an fifo overflow indication containing RNBC count. > > I think that both MPC and RNBC should be stored in rx_fifo_errors > > (and of cause still keeping them seperate to ethtool -S). > > This would count RNBC packets as packets that the stack did not > process, which it did. The MPC packets were not processed by the > stack and should be counted as dropped. As you point out, both counts > are available via ethtool -S. > > >I'll post two patches with these changes tomorrow, for you evaluation. > > Thanks, we look forward to see them. I'll keep it to one patch (with an extra comment reflecting this disscussion), as you have convinced me that the MPC should stay as "rx_missed", as this is presented to userspace as a positive drop. -- Med venlig hilsen / Best regards Jesper Brouer ComX Networks A/S Linux Network developer Cand. Scient Datalog / MSc. Author of http://adsl-optimizer.dk LinkedIn: http://www.linkedin.com/in/brouer ------------------------------------------------------------------------------ The NEW KODAK i700 Series Scanners deliver under ANY circumstances! Your production scanning environment may not be a perfect world - but thanks to Kodak, there's a perfect scanner to get the job done! With the NEW KODAK i700 Series Scanner you'll get full speed at 300 dpi even with all image processing features enabled. http://p.sf.net/sfu/kodak-com