Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262820AbTFGJFw (ORCPT ); Sat, 7 Jun 2003 05:05:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262657AbTFGJFw (ORCPT ); Sat, 7 Jun 2003 05:05:52 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:22547 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S262820AbTFGJFQ (ORCPT ); Sat, 7 Jun 2003 05:05:16 -0400 Date: Sat, 7 Jun 2003 10:18:48 +0100 From: Russell King To: Anton Blanchard Cc: linux-kernel@vger.kernel.org Subject: Re: irq consolidation Message-ID: <20030607101848.A22665@flint.arm.linux.org.uk> Mail-Followup-To: Anton Blanchard , linux-kernel@vger.kernel.org References: <20030607040515.GB28914@krispykreme> <20030607044803.GE28914@krispykreme> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20030607044803.GE28914@krispykreme>; from anton@samba.org on Sat, Jun 07, 2003 at 02:48:03PM +1000 X-Message-Flag: Your copy of Microsoft Outlook is vulnerable to viruses. See www.mutt.org for more details. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1893 Lines: 41 On Sat, Jun 07, 2003 at 02:48:03PM +1000, Anton Blanchard wrote: > We are hoping to kill irq_desc[NR_IRQS] completely and instead allocate > them on demand with some sort of hash to map an interrupt number to an > irq_desc. The same thought has crossed my mind as well for ARM; the hardware interrupt controllers are becoming more inteligent, and there is the possibility that system designers will mix inteligent interrupt controllers with standard types. Also on ARM, we're currently defining NR_IRQS on a per-platform class and even a per-platform basis. I've been wondering whether we even need to think about passing some alternative identifier of an IRQ line around, instead of a number. > Im working on top of Andrey Panin's irq consolidation patches > in the hope that it goes in first and other architectures can benefit > from these changes (I think SGI's ia64 boxes have similar issues as > well as large x86) I believe Andrey's IRQ consolidation provides a single flat IRQ structure. Unfortunately, this doesn't reflect the reality that we have on many ARM platforms - it remains the case that we need to decode IRQs on a multi-level basis. Given the rate which ARM has progressed and evolved during the existing 2.4 lifespan, it doesn't make much difference to us whether these changes happen now or later. If it happens later, it will be during the 2.6 series of kernels, so "now" is preferable. Reality is such that ARM hardware moves a hell of a lot faster than x86 hardware. -- Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html - 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/