From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934062AbXGYRKR (ORCPT ); Wed, 25 Jul 2007 13:10:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753135AbXGYRKE (ORCPT ); Wed, 25 Jul 2007 13:10:04 -0400 Received: from hera.kernel.org ([140.211.167.34]:41508 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753481AbXGYRKD (ORCPT ); Wed, 25 Jul 2007 13:10:03 -0400 From: Len Brown Organization: Intel Open Source Technology Center To: John Sigler Subject: Re: Pin-pointing the root of unusual application latencies Date: Wed, 25 Jul 2007 13:09:54 -0400 User-Agent: KMail/1.9.5 Cc: Ingo Molnar , linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org References: <469600F7.3060603@free.fr> <20070725133835.GA17616@elte.hu> <46A758B5.9070602@free.fr> In-Reply-To: <46A758B5.9070602@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707251309.54240.lenb@kernel.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 25 July 2007 10:05, John Sigler wrote: > # cat /proc/interrupts > CPU0 > 0: 37 XT-PIC-XT timer > 1: 2 XT-PIC-XT i8042 > 2: 0 XT-PIC-XT cascade > 7: 0 XT-PIC-XT acpi > 10: 175 XT-PIC-XT eth2, Dta1xx > 11: 1129 XT-PIC-XT eth0 > 12: 4 XT-PIC-XT eth1 > 14: 21482 XT-PIC-XT ide0 > NMI: 0 > LOC: 161632 > ERR: 0 > MIS: 0 > > IRQ 10 is shared between a NIC and an I/O board. > > For eth2, the kernel said: > ACPI: PCI Interrupt 0000:00:0a.0[A] -> Link [LNKC] > -> GSI 10 (level, low) -> IRQ 10 > > For Dta1xx, the kernel said: > ACPI: PCI Interrupt 0000:02:0e.0[A] -> Link [LNKC] > -> GSI 10 (level, low) -> IRQ 10 > > Is it possible to avoid the two boards sharing IRQ 10? Maybe. In this configuration, INTA of the two devices is physically connected to the same wire on the device-side of the interrupt re-mapper -- so you'd have to change the configuration. If you have an IOAPIC and can enable it, that will not hurt -- though unless something else changes, these devices are still tied together on the device-side of the mapper. So if you can physically move one of the devices to another slot that is your best bet. I'd need a bunch of info from your system to tell you what you can do ahead of time, including full dmesg, lspci -vv and acpidump. -Len