Re: [RFC] x86: merge nmi_32-64 to nmi.c

Mikael Pettersson
2008-05-17T21:49:02Z

Maciej W. Rozycki writes:
> On Sat, 17 May 2008, Tom Spink wrote:
>
> > static inline unsigned int get_nmi_count(int cpu)
> > {
> > #ifdef CONFIG_X86_64
> > return cpu_pda(cpu)->__nmi_count;
> > #else
> > return nmi_count(cpu);
> > #endif
> > }
> >
> > I know it introduces a lot of these conditionals, but at least there
> > is one place to look for the get_nmi_count function, instead of
> > searching for all variants of the function.
>
> Well, I suppose some header should provide a definition like:
>
> #ifdef CONFIG_X86_64
> #define cpu_x86_64 1
> #else
> #define cpu_x86_64 0
> #endif
>
> and the you can remove the horrible #ifdef clutter and make the quoted
> function look like:
>
> static inline unsigned int get_nmi_count(int cpu)
> {
> return cpu_x86_64 ? cpu_pda(cpu)->__nmi_count : nmi_count(cpu);
> }
>
> Much better -- isn't it?

IMO, no, the #ifdef is preferable.

Why? Because the #ifdef is a very visible signal to the platform
people that there are (in this case) subarch differences that force
"clients" to behave differently on different subarchs. By removing
the #ifdef you're IMO making it less likely for the platform people
to take notice and work towards eliminating those differences.