Is extern inline -> static inline OK?

[Tim Bird <tim.bird@am.sony.com>]

Pardon my ignorance...

Under what conditions is it NOT OK to convert "extern inline"
to "static inline"?

Linus once wrote:
>  - "static inline" means "we have to have this function, if you use it
>    but don't inline it, then make a static version of it in this
>    compilation unit"
> 
>  - "extern inline" means "I actually _have_ an extern for this function,
>    but if you want to inline it, here's the inline-version"
> 
> ... we should just convert
> all current users of "extern inline" to "static inline".

But Richard Henderson rejected (in 2002) the following patch (excerpt):

-#define __EXTERN_INLINE extern inline
+#define __EXTERN_INLINE static inline

presumably because the exact semantics of extern inline were
required.  I can only find __EXTERN_INLINE in the alpha
architecture.  Is the requirement to use 'extern' rather
than 'static' unique to alpha?

Thanks for any illumination on this.

=============================
Tim Bird
Architecture Group Co-Chair, CE Linux Forum
Senior Staff Engineer, Sony Electronics
E-mail: tim.bird@am.sony.com
=============================