From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767236AbXDET02 (ORCPT ); Thu, 5 Apr 2007 15:26:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767245AbXDET02 (ORCPT ); Thu, 5 Apr 2007 15:26:28 -0400 Received: from hera.kernel.org ([140.211.167.34]:36714 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767236AbXDET01 (ORCPT ); Thu, 5 Apr 2007 15:26:27 -0400 To: linux-kernel@vger.kernel.org From: Stephen Hemminger Subject: Re: IRQ splitting Date: Thu, 5 Apr 2007 12:23:41 -0700 Organization: OSDL Message-ID: <20070405122341.482f5e26@freekitty> References: <46150913.4000406@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Trace: build.pdx.osdl.net 1175801104 27345 10.8.0.202 (5 Apr 2007 19:25:04 GMT) X-Complaints-To: abuse@osdl.org NNTP-Posting-Date: Thu, 5 Apr 2007 19:25:04 +0000 (UTC) X-Newsreader: Sylpheed-Claws 2.5.0-rc3 (GTK+ 2.10.6; x86_64-pc-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 05 Apr 2007 08:34:59 -0600 Robert Hancock wrote: > Jan Engelhardt wrote: > > Hello list, > > > > > > > > let's take the following /proc/interrupts dump (CPU2,CPU3 trimmed)... > > > > CPU0 CPU1 > > 0: 37041766 37038991 IO-APIC-edge timer > > 1: 10 2 IO-APIC-edge i8042 > > 8: 0 0 IO-APIC-edge rtc > > 9: 0 0 IO-APIC-level acpi > > 12: 114 0 IO-APIC-edge i8042 > > 14: 25219 5800049 IO-APIC-edge ide0 > > 201: 260381 238454 IO-APIC-level aacraid > > 209: 0 0 IO-APIC-level ohci_hcd:usb1 > > 217: 0 0 IO-APIC-level ehci_hcd:usb2 > > 225: 57531742 0 IO-APIC-level eth0,radeon@pci:0000:03:00.0 > > 233: 26 0 IO-APIC-level eth1 > > NMI: 1661 1397 > > LOC: 147579966 147579949 > > ERR: 0 > > MIS: 0 > > > > My question is whether it is possible that eth0's interrupts go to CPU0 > > and radeon's to CPU1, and if so, how I would enable that. Alternatively, > > is it possible to just move eth0 or radeon to a different interrupt? > > Generally (at least in APIC mode) the IRQ assignments are based on > hard-wired interrupt lines on the board. In this case, the slots that > the Radeon and eth0 card are in likely share a physical interrupt line > and there is no way to separate them in software. You can try moving the > card(s) to different slots.. > If the radeon and/or the Ethernet driver support MSI, that would split out the IRQ's as well. -- Stephen Hemminger