From owner-freebsd-current@FreeBSD.ORG Fri Nov 12 13:49:13 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0D77516A4CE; Fri, 12 Nov 2004 13:49:13 +0000 (GMT) Received: from ss.eunet.cz (ss.eunet.cz [212.47.7.215]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4232A43D58; Fri, 12 Nov 2004 13:49:12 +0000 (GMT) (envelope-from mime@traveller.cz) Received: from [127.0.0.1] (ss [212.47.7.215]) by ss.eunet.cz (8.13.1/8.13.1) with ESMTP id iACDn0tx016449; Fri, 12 Nov 2004 14:49:03 +0100 (CET) (envelope-from mime@traveller.cz) Message-ID: <4194BF4C.5090007@traveller.cz> Date: Fri, 12 Nov 2004 14:49:00 +0100 From: Michal Mertl User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; cs-CZ; rv:1.7.2) Gecko/20041016 X-Accept-Language: cs, en-us, en MIME-Version: 1.0 To: "Wilkinson, Alex" , current@freebsd.org Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: RE: dealing with interupt storms ..... X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Nov 2004 13:49:13 -0000 Alext Wilkinson wrote: > Hi all, > > How does one stop an interrupt storm in RELENG_5 ? > >> >From top(1) > > CPU states: 10.9% user, 0.0% nice, 3.9% system, 85.3% interrupt, 0.0% idle > > >From vmstat(1) > > total rate > ----- ---- > irq18: uhci2 bt0++ 9187313 426 Answer to your question might be to modify sysctl hw.intr_storm_threshold. I can confirm, there is a problem in bktr(4) generating interrupt storms. For several months I was seeing messages about interrupt storms and system run fine (I haven't been using bktr for long time so I didn't care). I tried to roll the bktr sources as far back as possible (that is to the time before phk changed dev_t to struct cdev *) to no avail, so I suspect the problem is caused by something outside of the driver. After latest changes to interrupt throttling (rev. 1.117 of src/sys/kern_intr.c by jhb) the system performance is pretty affected until I unload bktr driver because bktr now seems to be doing some 120000 interrupts/second and not getting throttled). -- Michal Mertl