Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753700Ab0ADTDJ (ORCPT ); Mon, 4 Jan 2010 14:03:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753526Ab0ADTDH (ORCPT ); Mon, 4 Jan 2010 14:03:07 -0500 Received: from terminus.zytor.com ([198.137.202.10]:35539 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753422Ab0ADTDG (ORCPT ); Mon, 4 Jan 2010 14:03:06 -0500 Message-ID: <4B423B08.3010005@zytor.com> Date: Mon, 04 Jan 2010 11:01:28 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: "Eric W. Biederman" CC: Yinghai Lu , Jesse Brandeburg , Ingo Molnar , Thomas Gleixner , "linux-kernel@vger.kernel.org" , Andrew Morton , NetDEV list , Jesse Brandeburg Subject: Re: Subject: [PATCH 1/2] x86: get back 15 vectors References: <4B347AEE.6030705@kernel.org> <20091228094707.GH24690@elte.hu> <4B398ECD.1080506@kernel.org> <4807377b1001031906s6b1ee576jc021da2642bb4147@mail.gmail.com> <4B415E73.1050801@kernel.org> <4B419113.1090204@kernel.org> In-Reply-To: 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 Content-Length: 1033 Lines: 26 On 01/04/2010 08:18 AM, Eric W. Biederman wrote: > Yinghai Lu writes: > > This patch is wrong. > >> between FIRST_EXTERNAL_VECTOR (0x20) and FIRST_DEVICE_VECTOR (0x41) >> >> for 0x20 and 0x2f, we are safe be used_vectors will prevent it to use used one. > > We can not use any of 0x20 - 0x2f for ioapic irqs. We need the entire > priority level to ensure that the irq move cleanup ipi is of a lower > priority. > Almost makes one want to abuse 0x1f for that. Although 0x00..0x1f are reserved for exceptions, the APICs range down to 0x10, and well, when 0x1f ends up actually getting used as an exception vector that we support, then we can trivially change that. In the meantime it would actually make use of an otherwise-unusable APIC priority level. -hpa -- 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/