Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 24 Sep 2002 15:05:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 24 Sep 2002 15:05:11 -0400 Received: from ns.commfireservices.com ([216.6.9.162]:19975 "HELO hemi.commfireservices.com") by vger.kernel.org with SMTP id ; Tue, 24 Sep 2002 15:05:10 -0400 Date: Tue, 24 Sep 2002 15:10:02 -0400 (EDT) From: Zwane Mwaikambo X-X-Sender: zwane@montezuma.mastecende.com To: Mark Knecht Cc: Linux Kernel Subject: RE: SMP machines - IRQ Priorities In-Reply-To: <000101c263f9$dc646a10$b50aa8c0@mknecht> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2518 Lines: 56 On Tue, 24 Sep 2002, Mark Knecht wrote: > Zwane, > Yes, we understand that we can see a list. The problem is that we do not > understand whether IRQ0 is considered higher priority than IRQ23. > Unfortunately I do not have an SMP machine to look at myself right now, so > I'm relaying info to others. > > The traditional IRQ order was NOT in order, due to the history of the PC > architecture. If I was to simply guess that APIC priority was 0, 1, 2, 3, > ... 22, 23 I could easily be wrong. Possibly it's more like the traditional > model and would go more like 0, 1, 8, 9, 10, 11, 12, 13, 14, 15, 3, 4, 5, 6, > 7, 16, 17...23. We simply are not sure. > > Does the list you are speaking of show up in dmesg or somewhere else that > we can collect from people and compare the results we're getting in testing? Sorry i've got an annoying habit of being terse at times; The local APIC unit will handle interrupts depending on vector, with lowest being highest priority. Here is a sample table with NR being the IRQ e.g. 0 = 31; NR Log Phy Mask Trig IRR Pol Stat Dest Deli Vect: 00 00F 0F 0 0 0 0 0 1 1 31 01 00F 0F 1 0 0 0 0 1 1 39 02 000 00 1 0 0 0 0 0 0 00 03 00F 0F 0 0 0 0 0 1 1 41 04 00F 0F 0 0 0 0 0 1 1 49 05 00F 0F 0 0 0 0 0 1 1 51 06 00F 0F 1 0 0 0 0 1 1 59 07 00F 0F 0 0 0 0 0 1 1 61 08 00F 0F 0 0 0 0 0 1 1 69 09 00F 0F 0 0 0 0 0 1 1 71 0a 00F 0F 0 0 0 0 0 1 1 79 0b 00F 0F 0 0 0 0 0 1 1 81 0c 00F 0F 0 0 0 0 0 1 1 89 0d 00F 0F 0 0 0 0 0 1 1 91 0e 00F 0F 0 0 0 0 0 1 1 99 0f 00F 0F 0 0 0 0 0 1 1 A1 10 000 00 1 0 0 0 0 0 0 00 11 000 00 1 0 0 0 0 0 0 00 12 000 00 1 0 0 0 0 0 0 00 13 000 00 1 0 0 0 0 0 0 00 14 000 00 1 0 0 0 0 0 0 00 15 000 00 1 0 0 0 0 0 0 00 16 000 00 1 0 0 0 0 0 0 00 17 000 00 1 0 0 0 0 0 0 00 -- function.linuxpower.ca - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/