From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262941AbTJUF6W (ORCPT ); Tue, 21 Oct 2003 01:58:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262954AbTJUF6W (ORCPT ); Tue, 21 Oct 2003 01:58:22 -0400 Received: from diesel.grid4.com ([208.49.116.17]:18304 "EHLO diesel.grid4.com") by vger.kernel.org with ESMTP id S262941AbTJUF6U (ORCPT ); Tue, 21 Oct 2003 01:58:20 -0400 Date: Tue, 21 Oct 2003 01:59:23 -0400 From: Paul To: "Martin J. Bligh" Cc: linux-kernel@vger.kernel.org Subject: Re: IRQ Routing. [A 2.6 question about smp irq balancing] Message-ID: <20031021055923.GI13549@squish.home.loc> Mail-Followup-To: Paul , "Martin J. Bligh" , linux-kernel@vger.kernel.org References: <3F9396C7.50807@superbug.demon.co.uk> <763050000.1066659824@[10.10.2.4]> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <763050000.1066659824@[10.10.2.4]> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Martin J. Bligh" , on Mon Oct 20, 2003 [07:23:44 AM] said: > > Are their any linux tools to allow the user to view irq routing details, > > and maybe change the routing after boot ? > > > > This might be useful in special cases. > > Yeah, "cat /proc/interrupts" and > "echo > /proc/irq//smp_affinity" > > M. Hi; Here is my /proc/interrupts for 2.6.0-test6: CPU0 CPU1 0: 10442 1795758405 IO-APIC-edge timer 1: 737209 0 IO-APIC-edge i8042 2: 0 0 XT-PIC cascade 3: 517 1 IO-APIC-edge serial 4: 100488033 1 IO-APIC-edge serial 5: 0 0 IO-APIC-edge eth0 8: 2 0 IO-APIC-edge rtc 12: 1626560 1 IO-APIC-edge i8042 14: 8988748 8 IO-APIC-edge ide0 15: 377275 1 IO-APIC-edge ide1 16: 1364704 2 IO-APIC-level eth1 17: 857789 144630 IO-APIC-level eth2 19: 165579 1 IO-APIC-level Ensoniq AudioPCI NMI: 1795768424 1795763795 LOC: 1795877980 1795878044 ERR: 0 MIS: 351 Now, on 2.4 kernels, both columns are about even. Upon noticing this, I tried to get more interrupts on cpu1. You can see I got some on eth2, by running many 'ping -f's at the same time. I havent been able to get anything more out of ide[01] for cpu1, even though Ive run many -j4 compiles of huge packages, which coincided with other things that bring my load up to 8+ over the course of 20 days of uptime. /proc/irq//smp_affinity is 3 (ie. both cpus) for all . I was able to induce interrupts on cpu1 for ide0 by setting it to 2. Ok, my question is, is this how it is supposed to be? I ask because I am seeing a throughput decrease on 2.6 v 2.4 on hdparm -t, bonnie, kernel compile benchmarks, though interactivity seems to be better. Paul set@pobox.com