From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755435AbYKQAaS (ORCPT ); Sun, 16 Nov 2008 19:30:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753471AbYKQA37 (ORCPT ); Sun, 16 Nov 2008 19:29:59 -0500 Received: from terminus.zytor.com ([198.137.202.10]:45052 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752349AbYKQA37 (ORCPT ); Sun, 16 Nov 2008 19:29:59 -0500 Message-ID: <4920BA3A.5090100@zytor.com> Date: Sun, 16 Nov 2008 16:26:34 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Yinghai Lu CC: Benjamin Herrenschmidt , Andrew Morton , mingo@elte.hu, tglx@linutronix.de, linux-kernel@vger.kernel.org, travis@sgi.com Subject: Re: [PATCH] sparse_irq aka dyn_irq v13 References: <491434FB.2050904@kernel.org> <20081107124957.GA21709@elte.hu> <49168BD3.5010204@kernel.org> <20081109073813.GA17180@elte.hu> <86802c440811090003g5ac53822y852a4c1096228f8b@mail.gmail.com> <20081110094033.GL22392@elte.hu> <20081110015511.453a801e.akpm@linux-foundation.org> <4918065A.6050402@kernel.org> <20081110100329.GA19970@elte.hu> <491A9F87.8040403@kernel.org> <20081112120814.GG11352@elte.hu> <491C8B38.9060901@kernel.org> <20081113131850.d94fb229.akpm@linux-foundation.org> <1226869137.7178.175.camel@pasglop> <4920B069.5020203@kernel.org> <4920B15E.6090200@zytor.com> <4920B2A4.4040900@kernel.org> <4920B3E3.4050707@zytor.com> <4920B911.7060504@kernel.org> In-Reply-To: <4920B911.7060504@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Yinghai Lu wrote: >> >> I really don't think anyone gives a hoot about the IRQ number for any >> IRQ above the 0-15 legacy range, even including the "APIC" numbers 16+. > > you want to change ioapic/pin to irq mapping too? > so INTx and MSI will call create_irq_nr to get one irq for 16, and following first come and first serve rule. > I personally don't think there is any issue with changing ioapic/pin to IRQ mapping. Other people may disagree. My opinion is that IRQ numbers 16-23 are somewhat useful when you're dealing with a single IOAPIC, but after that it's all a blur. It would, however, be a good idea if IOAPICs had their numbers assigned at detection time, as opposed to when the interrupt is registered, thus making it a stable number for a single boot, at least. The same is probably true for MSI(-X); we could assign it a range of numbers when the device is enumerated (as opposed to when a driver is activated), but I don't know to what extent that is likely to cause more troubles than it solves. -hpa