Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757777AbYHSTBf (ORCPT ); Tue, 19 Aug 2008 15:01:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753020AbYHSTB1 (ORCPT ); Tue, 19 Aug 2008 15:01:27 -0400 Received: from ppsw-5.csi.cam.ac.uk ([131.111.8.135]:43926 "EHLO ppsw-5.csi.cam.ac.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752760AbYHSTB0 (ORCPT ); Tue, 19 Aug 2008 15:01:26 -0400 X-Greylist: delayed 1755 seconds by postgrey-1.27 at vger.kernel.org; Tue, 19 Aug 2008 15:01:26 EDT X-Cam-AntiVirus: no malware found X-Cam-SpamDetails: not scanned X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/ Message-ID: <48AB11A3.4060102@citrix.com> Date: Tue, 19 Aug 2008 19:32:03 +0100 From: Alex Nixon User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: Yinghai Lu CC: Ingo Molnar , Jeremy Fitzhardinge , Linux Kernel Mailing List Subject: Re: [PATCH] X86: Change the default value of nr_irqs from 32 to NR_IRQs References: <48AAFAE4.7070409@citrix.com> <86802c440808191044h74871ba1u62330dae18599436@mail.gmail.com> <0E902970173AF84089673FA54B7FE78A2CA11D@lonpexch01.citrite.net> <86802c440808191124v39ce2aa9rb548d3bdd75ca25c@mail.gmail.com> In-Reply-To: <86802c440808191124v39ce2aa9rb548d3bdd75ca25c@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1414 Lines: 36 Yinghai Lu wrote: > On Tue, Aug 19, 2008 at 11:13 AM, Alex Nixon (Intern) > wrote: >> Yinghai Lu wrote: >>> On Tue, Aug 19, 2008 at 9:55 AM, Alex Nixon wrote: >>>> If the number of discovered IRQs is suspiciously low, this patch causes >>>> the number reported to default to NR_IRQS, rather than 32. NR_IRQS has >>>> already been defined to be a >sensible value for the current system (in >>>> particular, at least 224 when paravirtualisation is involved). >>>> >>> if only one ioapic, nr will be 24<<1, you will get 48. Does pv has io apic >>> ? >>> >>> YH >>> >> I'm not sure about the general case, but Xen does not (Jeremy correct me if >> I'm wrong). >> >> Unless I'm missing something (which I may well be; I'm new to this area of >> code), it seems more logical anyway to default back to the calculated >> system-specific value (NR_IRQS), instead of 32, which seems rather >> arbitrary. > > can you try !CONFIG_HAVE_SPARSE_IRQ and CONFIG_HAVE_SPARSE_IRQ ? > > YH Sorry I should have mentioned originally - the bug occurs both with CONFIG_HAVE_SPARSE_IRQ enabled, and disabled. - Alex -- 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/