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>
3c7569b284