On Tue, Feb 21, 2006 at 09:48:21AM +1100, Simon Burge wrote:
> MIPS needs to use -mlong-calls to compile LKMs, and PowerPC and ARM use
> trampolines to call functions external to the LKM, so there's at least
> some performance hit for those architectures.

Isn't that what happens to all of the "far" calls in the kernel on
those processors anyway?  Sure, you might find that some of the
kernel API functions wind up linked close enough to be optimised to
short branches, but kernels are pretty large animals these days,
compared to the range of branches in most RISC architectures, so I
wouldn't want to bet on it being a really big performance hit.

-- 
Andrew