From owner-freebsd-hackers@FreeBSD.ORG Fri Apr 6 13:50:26 2007 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 4401016A402 for ; Fri, 6 Apr 2007 13:50:26 +0000 (UTC) (envelope-from volker@vwsoft.com) Received: from frontmail.ipactive.de (frontmail.maindns.de [85.214.95.103]) by mx1.freebsd.org (Postfix) with ESMTP id D2BAF13C448 for ; Fri, 6 Apr 2007 13:50:25 +0000 (UTC) (envelope-from volker@vwsoft.com) Received: from mail.vtec.ipme.de (Q7d21.q.ppp-pool.de [89.53.125.33]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by frontmail.ipactive.de (Postfix) with ESMTP id D2827128829; Fri, 6 Apr 2007 15:50:18 +0200 (CEST) Received: from [192.168.16.3] (cesar.sz.vwsoft.com [192.168.16.3]) by mail.vtec.ipme.de (Postfix) with ESMTP id CE1FD3F9E7; Fri, 6 Apr 2007 15:49:57 +0200 (CEST) Message-ID: <46165003.4070901@vwsoft.com> Date: Fri, 06 Apr 2007 15:49:55 +0200 From: Volker User-Agent: Thunderbird 1.5.0.10 (X11/20070306) MIME-Version: 1.0 To: Mike Tancsa References: <7.1.0.9.0.20070405163059.16b8a220@sentex.net> <200704061130.l36BUtjW064328@lava.sentex.ca> <46163987.4010409@vwsoft.com> <200704061228.l36CSJ8Z064543@lava.sentex.ca> In-Reply-To: <200704061228.l36CSJ8Z064543@lava.sentex.ca> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-VWSoft-MailScanner: Found to be clean X-MailScanner-From: volker@vwsoft.com X-ipactive-MailScanner-Information: Please contact the ISP for more information X-ipactive-MailScanner: Found to be clean X-ipactive-MailScanner-From: volker@vwsoft.com Cc: freebsd-hackers@freebsd.org Subject: Re: fixing IRQ storms X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Apr 2007 13:50:26 -0000 On 04/06/07 14:28, Mike Tancsa wrote: > At 08:13 AM 4/6/2007, Volker wrote: > >> Mike, >> >> have a look at GNAT: http://www.freebsd.org/cgi/query-pr.cgi?pr=51982 >> >> You need to patch your kernel sources a bit (all info in the PR) and >> your silo overflows will be gone. I've done that to get a Merlin >> U630 working (w/o patching sio.c the card was almost unusable). > > Hi, > Thanks for the note. Actually, I have done this in the past (I > am even in the above PR :)), but I had found using the UART driver > instead of sio was better for working around such issues on the whole. > The overflow rate is so high in the case, even increasing the ticks by > 10 doesnt seem to fix the issue. It seems to reduce the overflows a bit, > but nowhere nearly enough > > sio2: 108 more interrupt-level buffer overflows (total 108) > sio2: 81 more interrupt-level buffer overflows (total 189) > sio2: 108 more interrupt-level buffer overflows (total 297) > sio2: 81 more interrupt-level buffer overflows (total 378) > sio2: 33 more interrupt-level buffer overflows (total 411) > sio2: 76 more interrupt-level buffer overflows (total 487) > > With the uart driver, I am able to talk to the modem OK, but the cpu is > really high dealing with all those interrupts. > > I was hoping I could just tell the card to use a different interrupt > like 5 which is available, but I dont know how to do that, or if its > even possible. > > ---Mike Mike, I've played with uart(4) a while (~6mo?) back (for use with a Merlin 3G/GPRS card) and had even more trouble. Unfortunately I can't remember what errors I was experiencing with but I've had a short conversation with the uart maintainer. If my memories are right, the maintainer stated it will take some time to fix the uart problems. Haven't tried that since. But IMO the design of uart is definitely cleaner compared to sio. HTH, Volker