From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: intermittant petabyte usage reported with broadcom nic Date: Mon, 2 Apr 2007 00:13:00 -0700 Message-ID: <20070402001300.3b66007d.akpm@linux-foundation.org> References: <20070402014319.GA8345@zip.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: CaT Return-path: Received: from smtp.osdl.org ([65.172.181.24]:42217 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753359AbXDBHNE (ORCPT ); Mon, 2 Apr 2007 03:13:04 -0400 In-Reply-To: <20070402014319.GA8345@zip.com.au> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 2 Apr 2007 11:43:19 +1000 CaT wrote: > I take minute by minute snapshots of network traffic by sampling > /proc/net/dev and most of the time everything works fine. Occasionally > though I get petabyte byte traffic and corresponding packet traffic. How frequently? Are you able to provide some actual numbers (expected and actual values), so we can look at the bit patterns? > This happens on an AMD64, dual core smp box with Broadcom NetXtreme II > nics. What driver drivers that? b44.c? > The issue happens with both nics but at different times. The same > sampling code runs on p4 boxes with ht on and e1000 nics without issues > so I don't believe it's an issue with my code (famous last words :) > which just does an re to extract the data on a per-line basis and prints > it out. Still, I'll be adding code to log any big readings and hopefully > it'll happen again sooner rather then later. > > There is no preemption involved and the kernel is a monolythic build of > 2.6.19.[12] (there are two servers). We do perform racy 64-bit updates of some of the stats counters. But that'll only affect 32-bit kernels and I'm assuming you're running a 64-bit kernel on that AMD64 box (are you?) Plus it's odd that both the byte-counters and the packet-counters go wonky at the same time.