From owner-freebsd-current@FreeBSD.ORG Mon Nov 1 22:18:17 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 ECD5C16A4CE for ; Mon, 1 Nov 2004 22:18:16 +0000 (GMT) Received: from mail6.speakeasy.net (mail6.speakeasy.net [216.254.0.206]) by mx1.FreeBSD.org (Postfix) with ESMTP id 893F643D31 for ; Mon, 1 Nov 2004 22:18:16 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 14873 invoked from network); 1 Nov 2004 22:18:16 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 1 Nov 2004 22:18:15 -0000 Received: from [10.50.41.235] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.12.11/8.12.11) with ESMTP id iA1MIBOA062933; Mon, 1 Nov 2004 17:18:12 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: Shunsuke SHINOMIYA Date: Mon, 1 Nov 2004 17:03:17 -0500 User-Agent: KMail/1.6.2 References: <20041028165604.DCF8.SHINO@fornext.org> <200410281111.24398.jhb@FreeBSD.org> <20041030105024.360A.SHINO@fornext.org> In-Reply-To: <20041030105024.360A.SHINO@fornext.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200411011703.17866.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on server.baldwin.cx cc: freebsd-current@FreeBSD.org cc: obrien@FreeBSD.org Subject: Re: disabling interrupt storm protection 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: Mon, 01 Nov 2004 22:18:17 -0000 On Friday 29 October 2004 11:37 pm, Shunsuke SHINOMIYA wrote: > Thank you John, > > I wrote a patch(which is attached to this mail) so that the problem > doesn't occur in my environment. > > This patch changes the meaning of `storm'. > But, I think use of the parameter(hw_intr_threshold) to control the > detector in this method is clearer than the present method, and it > needs no DELAY(1). > > In the detector to which this patch is applied and compiled with > -DHACK2 flag, `storm' is the situation that the number of generated > interrupts per unit time(1/hz) is larger than threshold. > > If kern_intr.c is compiled with -DHACK2 -DHACK3 flags, it works as > interrupt rate limiter. > > What do you think about this method? A true interrupt storm that is trying to be handled here is not necessarily a high rate of interrupts (that can just be high load, but that is ok), but instead when a level triggered interrupt isn't handled it ends up firing again as soon as you re-enable interrupts. The goal is to at least give the system some time to run with the constantly interrupting source disabled so that other work can be done. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org