From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757863Ab0JYXFx (ORCPT ); Mon, 25 Oct 2010 19:05:53 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46989 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755181Ab0JYXFw (ORCPT ); Mon, 25 Oct 2010 19:05:52 -0400 Message-ID: <4CC60D3A.1020201@zytor.com> Date: Mon, 25 Oct 2010 16:05:30 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Konrad Rzeszutek Wilk , Ian Campbell , Stefano Stabellini , linux-kernel@vger.kernel.org, mingo@elte.hu, xen-devel@lists.xensource.com, tglx@linutronix.de Subject: Re: [PATCH 1/5] xen: events: use irq_alloc_desc(_at) instead of open-coding an IRQ allocator. References: <1288023736.11153.40.camel@zakaz.uk.xensource.com> <1288023813-31989-1-git-send-email-ian.campbell@citrix.com> <20101025173522.GA5590@dumpdata.com> <4CC60CB7.3070005@goop.org> In-Reply-To: <4CC60CB7.3070005@goop.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/25/2010 04:03 PM, Jeremy Fitzhardinge wrote: > > What? Why? How? Surely if we're asking the irq subsystem to allocate > us an irq, it will return a fresh never-before-used (and certainly not > shared) irq? Shared irqs only make sense if multiple devices are > actually sharing, say, a wire on the board. > > Or am I missing something? > I think the number is not necessarily "never before used", but rather "not currently used". -hpa