Messages in this thread | | | Date | Sat, 02 Aug 2008 23:44:53 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH] x86_64: Restore the proper NR_IRQS define so larger systems work. |
| |
Yinghai Lu wrote: > On Sat, Aug 2, 2008 at 10:26 PM, Eric W. Biederman > <ebiederm@xmission.com> wrote: > >> As pointed out and tracked by Yinghai Lu <yhlu.kernel@gmail.com>: >> >> 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 <tglx@linutronix.de> >> 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 <dhaval@linux.vnet.ibm.com> tested an earlier version of >> this patch by YH which confirms simply increasing NR_IRQS fixes the >> problem. >> >> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> >> --- >> 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
| |