From owner-freebsd-stable@FreeBSD.ORG Mon Dec 17 05:43:06 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 327D516A469 for ; Mon, 17 Dec 2007 05:43:06 +0000 (UTC) (envelope-from jdc@parodius.com) Received: from mx01.sc1.parodius.com (mx01.sc1.parodius.com [72.20.106.3]) by mx1.freebsd.org (Postfix) with ESMTP id 2AC3B13C465 for ; Mon, 17 Dec 2007 05:43:06 +0000 (UTC) (envelope-from jdc@parodius.com) Received: by mx01.sc1.parodius.com (Postfix, from userid 1000) id 0648F1CC079; Sun, 16 Dec 2007 21:43:06 -0800 (PST) Date: Sun, 16 Dec 2007 21:43:06 -0800 From: Jeremy Chadwick To: Mark Fullmer Message-ID: <20071217054305.GA18268@eos.sc1.parodius.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.16 (2007-06-09) Cc: freebsd-stable@freebsd.org Subject: Re: Packet loss every 30.999 seconds X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Dec 2007 05:43:06 -0000 On Mon, Dec 17, 2007 at 12:21:43AM -0500, Mark Fullmer wrote: > While trying to diagnose a packet loss problem in a RELENG_6 snapshot dated > November 8, 2007 it looks like I've stumbled across a broken driver or > kernel routine which stops interrupt processing long enough to severly > degrade network performance every 30.99 seconds. > > Packets appear to make it as far as ether_input() then get lost. Are you sure this isn't being caused by something the switch is doing, such as MAC/ARP cache clearing or LACP? I'm just speculating, but it would be worthwhile to remove the switch from the picture (crossover cable to the rescue). I know that at least in the case of fxp(4) and em(4), Jack Vogel does some through testing of throughput using a professional/high-end packet generator (some piece of hardware, I forget the name...) -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |