From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gw.goop.org ([64.81.55.164]:49179 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946212AbXBPSi7 (ORCPT ); Fri, 16 Feb 2007 13:38:59 -0500 Message-ID: <45D5F2EC.5000402@goop.org> Date: Fri, 16 Feb 2007 10:07:40 -0800 From: Jeremy Fitzhardinge MIME-Version: 1.0 Subject: Re: [RFC] killing the NR_IRQS arrays. References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org To: "Eric W. Biederman" Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Andi Kleen , Benjamin Herrenschmidt , Ingo Molnar , Alan Cox List-ID: Eric W. Biederman wrote: > So I propose we remove all assumptions from the code that we actually > have an array of irqs. That will allow for irq_desc to be dynamically > allocated instead of statically allocated saving memory and reducing > kernel complexity. > Sounds good to me. In Xen we have 1024 event channels which we need to map down into a smaller irq. Aside from the complexity of maintaining a mapping table, that's not a huge issue for now, but when we start exposing pci devices to guests it all becomes more complex. The ideal for us is to simply use event channel == irq, which this would allow. J