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x86_64: restore the proper NR_IRQS define so larger systems work.

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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 9b7dc567d0
       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>
Acked-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Eric W. Biederman 2008-08-10 00:35:50 -07:00 committed by Ingo Molnar
parent d388e5fdc4
commit 3c7569b284
1 changed files with 9 additions and 1 deletions
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10
include/asm-x86/irq_vectors.h
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@ -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)