strange code in include/linux/kernel_stat.h

strange code in include/linux/kernel_stat.h

[Dmitri Vorobiev]

Hi,

Depending on whether the CONFIG_GENERIC_HARDIRQS option is enabled or not, the header file include/linux/kernel_stat.h defines the following two entities:

- the macro kstat_irqs_this_cpu for the case when CONFIG_GENERIC_HARDIRQS is set:

#define kstat_irqs_this_cpu(DESC) \
        ((DESC)->kstat_irqs[smp_processor_id()])

- another macro with the same name as the macro above but for the case CONFIG_GENERIC_HARDIRQS is not set:

#define kstat_irqs_this_cpu(irq) \
        (kstat_this_cpu.irqs[irq])

Apparently, it is assumed that the types for the macro argument are different, and depend on the value of CONFIG_GENERIC_HARDIRQS. Is this intentional?

Thanks,
Dmitri

Re: strange code in include/linux/kernel_stat.h

[Dmitri Vorobiev]

Dmitri Vorobiev wrote:
> Hi,
> 
> Depending on whether the CONFIG_GENERIC_HARDIRQS option is enabled or not, the header file include/linux/kernel_stat.h defines the following two entities:
> 
> - the macro kstat_irqs_this_cpu for the case when CONFIG_GENERIC_HARDIRQS is set:
> 
> #define kstat_irqs_this_cpu(DESC) \
>         ((DESC)->kstat_irqs[smp_processor_id()])
> 
> - another macro with the same name as the macro above but for the case CONFIG_GENERIC_HARDIRQS is not set:
> 
> #define kstat_irqs_this_cpu(irq) \
>         (kstat_this_cpu.irqs[irq])
> 
> Apparently, it is assumed that the types for the macro argument are different, and depend on the value of CONFIG_GENERIC_HARDIRQS. Is this intentional?
> 

I still would like to know what's going on there. Anyone knowledgeable out there, please?

Dmitri 

> Thanks,
> Dmitri
> 
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