From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262155AbTHTSvT (ORCPT ); Wed, 20 Aug 2003 14:51:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262156AbTHTSvT (ORCPT ); Wed, 20 Aug 2003 14:51:19 -0400 Received: from havoc.gtf.org ([63.247.75.124]:61060 "EHLO havoc.gtf.org") by vger.kernel.org with ESMTP id S262155AbTHTSvQ (ORCPT ); Wed, 20 Aug 2003 14:51:16 -0400 Date: Wed, 20 Aug 2003 14:51:16 -0400 From: Jeff Garzik To: linux-kernel@vger.kernel.org Cc: torvalds@osdl.org, alan@lxorguk.ukuu.org.uk Subject: [rfc][patch] increase irq 12 penalty Message-ID: <20030820185116.GG23984@gtf.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is something that Red Hat ships in its kernel. I was thinking it belonged upstream, but was told "Alan rejected it; reason forgotten" :) Here is the logic for the patch: > It makes the "pick any IRQ" code in the kernel not pick irq12 by default. > irq12 is the ps/2 irq that gets emulated by smm on laptops. > Using that can be sudden death on several machines. > So the patch makes the cost of using it higher than the other irq's. Arjan, one of our RH kernel rpm maintainers, also adds: > for all I know it's totally wrong > but it fixed some machines and it doesn't seem to break any So I thought I would send it to lkml for comments. RH has been carrying this for a while... diff -urNp linux-1090/arch/i386/kernel/pci-irq.c linux-1100/arch/i386/kernel/pci-irq.c --- linux-1090-arch-i386/kernel/pci-irq.c +++ linux-1100-arch-i386/kernel/pci-irq.c @@ -36,7 +36,7 @@ unsigned int pcibios_irq_mask = 0xfff8; static int pirq_penalty[16] = { 1000000, 1000000, 1000000, 1000, 1000, 0, 1000, 1000, - 0, 0, 0, 0, 1000, 100000, 100000, 100000 + 0, 0, 0, 0, 2500, 100000, 100000, 100000 }; struct irq_router { [note, patch pathnames mangled to prevent immediate application :)]