From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755317AbYHCGpO (ORCPT ); Sun, 3 Aug 2008 02:45:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751838AbYHCGpB (ORCPT ); Sun, 3 Aug 2008 02:45:01 -0400 Received: from gw.goop.org ([64.81.55.164]:58095 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751744AbYHCGpA (ORCPT ); Sun, 3 Aug 2008 02:45:00 -0400 Message-ID: <489553E5.4020908@goop.org> Date: Sat, 02 Aug 2008 23:44:53 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Yinghai Lu CC: "Eric W. Biederman" , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , Dhaval Giani , Mike Travis , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86_64: Restore the proper NR_IRQS define so larger systems work. References: <1217642575-22727-1-git-send-email-yhlu.kernel@gmail.com> <86802c440808022258x1198093x7d21274b82e75f4b@mail.gmail.com> In-Reply-To: <86802c440808022258x1198093x7d21274b82e75f4b@mail.gmail.com> X-Enigmail-Version: 0.95.6 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 Yinghai Lu wrote: > On Sat, Aug 2, 2008 at 10:26 PM, Eric W. Biederman > wrote: > >> As pointed out and tracked by Yinghai Lu : >> >> Dhaval Giani got: >> kernel BUG at arch/x86/kernel/io_apic_64.c:357! >> invalid opcode: 0000 [1] SMP >> CPU 24 >> ... >> >> his system (x3950) has 8 ioapic, irq > 256 >> >> This was caused by: >> commit 9b7dc567d03d74a1fbae84e88949b6a60d922d82 >> Author: Thomas Gleixner >> Date: Fri May 2 20:10:09 2008 +0200 >> >> x86: unify interrupt vector defines >> >> The interrupt vector defines are copied 4 times around with minimal >> differences. Move them all into asm-x86/irq_vectors.h >> >> It appears that Thomas did not notice that x86_64 does something >> completely different when he merge irq_vectors.h >> >> We can solve this for 2.6.27 by simply reintroducing the old heuristic >> for setting NR_IRQS on x86_64 to a usable value, which trivially removes >> the regression. >> >> Long term it would be nice to harmonize the handling of ioapic interrupts >> of x86_32 and x86_64 so we don't have this kind of confusion. >> >> Dhaval Giani tested an earlier version of >> this patch by YH which confirms simply increasing NR_IRQS fixes the >> problem. >> >> Signed-off-by: Eric W. Biederman >> --- >> include/asm-x86/irq_vectors.h | 10 +++++++++- >> 1 files changed, 9 insertions(+), 1 deletions(-) >> >> diff --git a/include/asm-x86/irq_vectors.h b/include/asm-x86/irq_vectors.h >> index 90b1d1f..a13eb6c 100644 >> --- a/include/asm-x86/irq_vectors.h >> +++ b/include/asm-x86/irq_vectors.h >> @@ -109,7 +109,15 @@ >> #define LAST_VM86_IRQ 15 >> #define invalid_vm86_irq(irq) ((irq) < 3 || (irq) > 15) >> >> -#if !defined(CONFIG_X86_VOYAGER) >> +#ifdef CONFIG_X86_64 >> +# if NR_CPUS < MAX_IO_APICS >> +# define NR_IRQS (NR_VECTORS + (32 * NR_CPUS)) >> +# else >> +# define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS )) >> +# endif >> +# define NR_IRQ_VECTORS NR_IRQS >> + >> +#elif !defined(CONFIG_X86_VOYAGER) >> >> # if defined(CONFIG_X86_IO_APIC) || defined(CONFIG_PARAVIRT) || defined(CONFIG_X86_VISWS) >> >> > > what should xen pv 64 get for NR_IRQS? > Much the same as usual; perhaps a bit lower. 16/CPU would probably be ample. But given that the kernel also needs to be able to boot native properly, just choosing the normal number would be best. I long for the day it becomes dynamic... J