From owner-freebsd-current@FreeBSD.ORG Thu Oct 28 18:56:13 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 8740216A4CE for ; Thu, 28 Oct 2004 18:56:13 +0000 (GMT) Received: from mail4.speakeasy.net (mail4.speakeasy.net [216.254.0.204]) by mx1.FreeBSD.org (Postfix) with ESMTP id 58EBE43D48 for ; Thu, 28 Oct 2004 18:56:13 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 22060 invoked from network); 28 Oct 2004 18:56:12 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 28 Oct 2004 18:56:12 -0000 Received: from [10.50.40.221] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.12.11/8.12.11) with ESMTP id i9SIu7Qt030006; Thu, 28 Oct 2004 14:56:08 -0400 (EDT) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: Shunsuke SHINOMIYA Date: Thu, 28 Oct 2004 11:11:24 -0400 User-Agent: KMail/1.6.2 References: <20041022171924.73B3.SHINO@fornext.org> <200410271352.04069.jhb@FreeBSD.org> <20041028165604.DCF8.SHINO@fornext.org> In-Reply-To: <20041028165604.DCF8.SHINO@fornext.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200410281111.24398.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: Thu, 28 Oct 2004 18:56:13 -0000 On Thursday 28 October 2004 06:13 am, Shunsuke SHINOMIYA wrote: > Thank you, John. > > > Can you try this patch: > > > > --- //depot/vendor/freebsd/src/sys/kern/kern_intr.c 2004/09/05 02:10:52 > > +++ //depot/projects/smpng/sys/kern/kern_intr.c 2004/10/27 17:41:06 > > snip > > > First, can you test that your system works with the default threshold, > > and second, can you test that setting the threshold to zero disables the > > storm detection? > > I applied your patch to kern_intr.c, and then I transmitted the high > rate(148kpps) IP traffic to the box with the default threshold. But > storm protection was not invoked. > > It seem that sensitivity of the detector is fallen. > > I tried some patterns of the packet loss test(transmitting the packets > of the wire rate in 100Mbps to the box for 10 seconds. The frame size > of each packets is 64 octet). > > These results are as follows. > > Each `before' and `after' are outputs of `vmstat -i | grep em'. Please > observe the first numerical value(number of interrupts since system > startup). kern.hz is 100 at all trials. And `Interrupt Moderation', one > of the feature of em was disabled. > > ========== > o kern_intr.c applied your patch. > o hw.intr_storm_threshold=500(default) > > remark > o The test results of both 1st and 2nd trial are good, low packet loss > rate. A difference of both trials may be measurement error. > o Interrupt storm protections is not invoked. > o The interrupts rate of em0(input side) is about 25000 interrupts per > second during a trial. > o When hw.intr_storm_threshold=200, Interrupt storm protections is not > invoked. Excellent, thanks. I feared that the stuff under #ifdef HACK was causing false positives. I'll revert the code to the non-HACK version in HEAD and will get it into RELENG_5 at some point (though it is probably too late for 5.3.) -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org