Date: Sun, 16 Dec 2007 21:43:06 -0800 From: Jeremy Chadwick <koitsu@FreeBSD.org> To: Mark Fullmer <maf@eng.oar.net> Cc: freebsd-stable@freebsd.org Subject: Re: Packet loss every 30.999 seconds Message-ID: <20071217054305.GA18268@eos.sc1.parodius.com> In-Reply-To: <C921285B-91B3-43BD-B440-128EC60CE815@eng.oar.net> References: <C921285B-91B3-43BD-B440-128EC60CE815@eng.oar.net>
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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 |
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