Re: [PATCH] x86: 64bit support more than 256 irq v2

From: Yinghai Lu
Date: Mon Aug 04 2008 - 14:20:02 EST


On Mon, Aug 4, 2008 at 6:20 AM, Mike Travis <travis@xxxxxxx> wrote:
> Eric W. Biederman wrote:
>> "Yinghai Lu" <yhlu.kernel@xxxxxxxxx> writes:
>>
>>> On Fri, Aug 1, 2008 at 7:02 PM, Yinghai Lu <yhlu.kernel@xxxxxxxxx> wrote:
>>>> 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
>>>>
>>>> caused by
>>>> commit 9b7dc567d03d74a1fbae84e88949b6a60d922d82
>>>> Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>>>> 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
>>>>
>>>> because 64bit allow same vector for different cpu to serve different irq
>>>>
>>>> need to create that array dynamically later
>>>>
>>>> v2: change NR_IRQS to 1024
>>>>
>>>> Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>
>>>> Tested-by: Dhaval Giani <dhaval@xxxxxxxxxxxxxxxxxx>
>>> this is for
>>> http://bugzilla.kernel.org/show_bug.cgi?id=11201
>>>
>>> but need SGI guys to verify in their system. they like to have NR_IRQS to be 224
>>
>> There was a patch that came out a while ago that set NR_IRQS as NR_IOAPICS*32 from
>> SGI. Where that got to I don't recall.
>>
>> Eric
>
> That was from Alan ... I'll Cc: him. Here's an early copy (not sure if
> this was the final one though.)
>
>
>>From: Alan Mayer <ajm@xxxxxxx>
> Subject: [PATCH] x86_64: resize NR_IRQS for large machines
>
> On machines with very large numbers of cpus, tables that are dimensioned
> by NR_IRQS get very large, especially the irq_desc table. They are also
> very sparsely used. When the cpu count is > MAX_IO_APICS, use MAX_IO_APICS
> to set NR_IRQS, otherwise use NR_CPUS.
>
> Reviewed-by: Christoph Lameter <clameter@xxxxxxx>
>
> Signed-off-by: Alan Mayer <ajm@xxxxxxx>
> Index: v2.6.25-rc6/include/asm-x86/irq_64.h
> ===================================================================
> --- v2.6.25-rc6.orig/include/asm-x86/irq_64.h 2008-03-19 16:52:52.000000000 -0500
> +++ v2.6.25-rc6/include/asm-x86/irq_64.h 2008-03-20 16:46:51.000000000 -0500
> @@ -10,6 +10,10 @@
> * <tomsoft@xxxxxxxxxxxxxxxxxxxxxxxxx>
> */
>
> +#if !defined(MAX_IO_APICS)
> +#include <asm/apicdef.h>
> +#endif
> +
> #define TIMER_IRQ 0
>
> /*
> @@ -31,7 +35,11 @@
>
> #define FIRST_SYSTEM_VECTOR 0xef /* duplicated in hw_irq.h */
>
> -#define NR_IRQS (NR_VECTORS + (32 *NR_CPUS))
> +#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
>
> static __inline__ int irq_canonicalize(int irq)
> Index: v2.6.25-rc6/include/linux/kernel_stat.h
> ===================================================================
> --- v2.6.25-rc6.orig/include/linux/kernel_stat.h 2008-03-19 16:53:00.000000000 -0500
> +++ v2.6.25-rc6/include/linux/kernel_stat.h 2008-03-20 11:12:27.000000000 -0500
> @@ -1,11 +1,11 @@
> #ifndef _LINUX_KERNEL_STAT_H
> #define _LINUX_KERNEL_STAT_H
>
> -#include <asm/irq.h>
> #include <linux/smp.h>
> #include <linux/threads.h>
> #include <linux/percpu.h>
> #include <linux/cpumask.h>
> +#include <asm/irq.h>
> #include <asm/cputime.h>
>
> /*
>

so this one have right sequence...

could add sth say why need special including sequence...

YH
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