Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753892Ab0ADTE6 (ORCPT ); Mon, 4 Jan 2010 14:04:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753776Ab0ADTE5 (ORCPT ); Mon, 4 Jan 2010 14:04:57 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:57051 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753643Ab0ADTE4 (ORCPT ); Mon, 4 Jan 2010 14:04:56 -0500 To: Yinghai Lu Cc: Jesse Brandeburg , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , "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> <4B42362F.7040302@kernel.org> From: ebiederm@xmission.com (Eric W. Biederman) Date: Mon, 04 Jan 2010 11:04:46 -0800 In-Reply-To: <4B42362F.7040302@kernel.org> (Yinghai Lu's message of "Mon\, 04 Jan 2010 10\:40\:47 -0800") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on in01.mta.xmission.com); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1455 Lines: 40 Yinghai Lu writes: > 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. >> >>> also try to reuse 0x30 to 0x3f after smp_affinity for irq[0,15] is changed to other cpu. >> >> There may be a point with 0x30 to 0x3f as I recall when those irqs come through a legacy >> pic we need to reserve those vectors on all cpus. > > ok, I see. > > any reason that we can not use 0x40? Not that I now of. Reading the comment it looks like it was only skipped so that the initial assignment of vectors would be. 0x31, 0x41, 0x51, 0x61, 0x71, 0x81, 0x91, 0xa1, 0xb1, 0xc1, 0xd1, 0xe1 Instead of. 0x30, 0x40, 0x50, 0x60, 0x70, 0x90, 0xa0, 0xb0, 0xc0, 0xc0, 0xe0 Which doesn't seem to be the worst notion, but at the point we are looking for every vector we can get it does seem to be problematic. Eric -- 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/