From owner-freebsd-hackers@FreeBSD.ORG Mon Jul 17 16:41:13 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E564916A4E0; Mon, 17 Jul 2006 16:41:13 +0000 (UTC) (envelope-from xfb52@dial.pipex.com) Received: from smtp-out4.blueyonder.co.uk (smtp-out4.blueyonder.co.uk [195.188.213.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8027043D49; Mon, 17 Jul 2006 16:41:12 +0000 (GMT) (envelope-from xfb52@dial.pipex.com) Received: from [172.23.170.139] (helo=anti-virus01-10) by smtp-out4.blueyonder.co.uk with smtp (Exim 4.52) id 1G2W9f-0001lf-VV; Mon, 17 Jul 2006 17:41:12 +0100 Received: from [82.41.34.175] (helo=[192.168.0.2]) by asmtp-out4.blueyonder.co.uk with esmtp (Exim 4.52) id 1G2W9f-0002Ll-4n; Mon, 17 Jul 2006 17:41:11 +0100 Message-ID: <44BBBDA6.4010209@dial.pipex.com> Date: Mon, 17 Jul 2006 17:41:10 +0100 From: Alex Zbyslaw User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-GB; rv:1.7.13) Gecko/20060515 X-Accept-Language: en MIME-Version: 1.0 To: John Baldwin References: <44BB9D21.3010400@dial.pipex.com> <200607171128.00303.jhb@freebsd.org> In-Reply-To: <200607171128.00303.jhb@freebsd.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org Subject: Re: [Fwd: Interrupts question] 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: Mon, 17 Jul 2006 16:41:14 -0000 John Baldwin wrote: >On Monday 17 July 2006 10:22, Alex Zbyslaw wrote: > > >>No responses from questions@. Anyone here understand what's going on? >>Thanks]. >>__ >>I was monitoring a machine with "systat -vmstat" and noticed something >>about the interrupts and I don't know if it's a problem or not. If it >>is a problem, is there anything I can do about it? >> >>The interrupts for the network interface (em0) on irq 64 exactly match >>those for a uhc device on irq 16. >> >>And the interrupts for the hardware raid (amr) on irq 46 exactly match >>those for a uhc device on irq 18. >> >>The machine is a Dell 2850 running 5.4. Relevant bits from the dmesg are: >> >> > >FAQ. It's due to brain damage in the Intel PCIX hubs and can't be fixed >directly. > > > Thanks. I did search and couldn't find anything; guess I didn't search for the right thing :-( Any idea how much this might impact performance, especially of the disk? One thing I realised I missed from original dmesg was > Interrupt storm detected on "irq18: uhci2"; throttling interrupt source which ties to the disk interrupt. Will that be slowing things down? Would increasing the storm threshold help (especially disk performance)? Guess I'm looking for any mitigation that might be possible. Thanks again, --Alex