From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932156AbWFZR7A (ORCPT ); Mon, 26 Jun 2006 13:59:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932143AbWFZR6i (ORCPT ); Mon, 26 Jun 2006 13:58:38 -0400 Received: from mail.gmx.de ([213.165.64.21]:57568 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1751245AbWFZR6f (ORCPT ); Mon, 26 Jun 2006 13:58:35 -0400 X-Authenticated: #5039886 Date: Mon, 26 Jun 2006 19:58:44 +0200 From: =?iso-8859-1?Q?Bj=F6rn?= Steinbrink To: Mike Galbraith Cc: Arjan van de Ven , linux-kernel@vger.kernel.org, danial_thom@yahoo.com, Linus Torvalds , Andrew Morton Subject: Re: [PATCH] i386: Fix softirq accounting with 4K stacks Message-ID: <20060626175844.GA3822@atjola.homenet> Mail-Followup-To: =?iso-8859-1?Q?Bj=F6rn?= Steinbrink , Mike Galbraith , Arjan van de Ven , linux-kernel@vger.kernel.org, danial_thom@yahoo.com, Linus Torvalds , Andrew Morton References: <1151166193.8516.8.camel@Homer.TheSimpsons.net> <20060624192523.GA3231@atjola.homenet> <1151211993.8519.6.camel@Homer.TheSimpsons.net> <20060625111238.GB8223@atjola.homenet> <20060625142440.GD8223@atjola.homenet> <1151257451.7858.45.camel@Homer.TheSimpsons.net> <1151257397.4940.45.camel@laptopd505.fenrus.org> <20060625184244.GA11921@atjola.homenet> <1151288602.7470.22.camel@Homer.TheSimpsons.net> <1151291114.7611.8.camel@Homer.TheSimpsons.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1151291114.7611.8.camel@Homer.TheSimpsons.net> User-Agent: Mutt/1.5.11+cvs20060403 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 2006.06.26 05:05:14 +0200, Mike Galbraith wrote: > On Mon, 2006-06-26 at 04:23 +0200, Mike Galbraith wrote: > > > Something is certainly still b0rken. I still get three different > > answers to the question "what is my cpu usage" depending on > > configuration. With stock UP kernel with no IO-APIC, interrupt load is > > all hi. With your patch and IO-APIC, it's all si. SMP shows a mix of > > both. > > I didn't say that quite right. > > The third case for my box is XT-PIC and your patch. Previously, top > showed the 10% interrupt load of a flood ping as all hi. Now it's both > hi and si when using XT-PIC, but it's no longer the 10% that agreed with > the profile, it's 10% hi, but with an added ~7% si. I see the following here, when a box is being ping flooded: UP/SMP stack-size PIC-type hi si ----------------------------------- UP 8K IO-APIC 0 16 UP 8K XT-PIC 7 7 UP 4K IO-APIC 0 16 UP 4K XT-PIC 7 7 SMP 8K IO-APIC 5 4 (forcedeth) SMP 8K IO-APIC 0 11 (tg3) The UP system is a Thinkpad which only has a tg3 driven NIC. The SMP system is x86_64, so there's no 4K stacks to test with, maybe I'll fetch a i386 live CD to do some more valid tests on SMP. The UP tests seem to show the IO-APIC hardirq are completely deferred to be handled in a softirq, as the sum of "hi" and "si" with XT-PIC is about equal to the "si" value with IO-APIC (the numbers are guessed averages of the observed values, so the 2% difference is not too be taken too serious). The results for the forcedeth driven NIC do not agree though, and your results differ from what I see as well, right? So I'm kinda lost again. Björn