From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263391AbTDSRkL (ORCPT ); Sat, 19 Apr 2003 13:40:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263398AbTDSRkL (ORCPT ); Sat, 19 Apr 2003 13:40:11 -0400 Received: from mail.ithnet.com ([217.64.64.8]:43794 "HELO heather.ithnet.com") by vger.kernel.org with SMTP id S263391AbTDSRkK (ORCPT ); Sat, 19 Apr 2003 13:40:10 -0400 Date: Sat, 19 Apr 2003 19:38:48 +0200 From: Stephan von Krawczynski To: Kai Germaschewski Cc: linux-kernel Subject: Re: ISDN massive packet drops while DVD burn/verify Message-Id: <20030419193848.0811bd90.skraw@ithnet.com> In-Reply-To: References: <20030416151221.71d099ba.skraw@ithnet.com> Organization: ith Kommunikationstechnik GmbH X-Mailer: Sylpheed version 0.8.11 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 18 Apr 2003 09:25:21 -0500 (CDT) Kai Germaschewski wrote: > On Wed, 16 Apr 2003, Stephan von Krawczynski wrote: > > > I just experienced a massive ISDN problem while writing DVDs. > > It looks like bigger IP packets (bigger than normal ICMP ping) > > get simply dropped most of the time. > > I think the packets get lost because some allocation continously fails and > > disk i/o is faster in re-gaining the mem, but I am not quite sure. Could as > > well be ide-scsi is partially busy-looping the box to death. > > As soon as DVD writing is stopped everything comes back to normal. > > Reading DVDs does not show the problem btw. > > ping -s 1500 a.b.c.d shows about 5 packets, then stops. > > My best guess would be that IDE blocks IRQs for too long and hisax > interrupts get lost. You could try whether hdparm -u1 helps, and a > debugging log from the hisax driver may confirm over/underruns. I don't buy that explanation. Reason is simple: during this all network connections work flawlessly, and they do have quite a lot of interrupts compared to ISDN. ISDN is so slow and has so few interrupts that it is quite unlikely in a SMP-beyond-GHz-limit box that you loose some. The ancient hardware days are long gone ... > --Kai Regards Stephan