re: Is there a way to obtain a machine's cache line size?

[matthew green <mrg%eterna.com.au@localhost>]

> >> I see there is a compile time constant CACHE_LINE_SIZE in
> >> <sys/param.h> which currently seems to be always be set to 64, but
> >> I'm pretty certain that is not necessarily a correct value.
> > 
> > You are correct; to cite the one example I currently have swapped into
> > my brain, the Super-H used in the Dreamcast has 32-byte cache lines
> > (true of the I-cache and D-cache both).
> 
> I'm curious why non-kernel components would care.

i'd guess it's all for performance reasons.

> The question also gets amusing when the cache line size varies among
> the caches.  That's not all that common, but it certainly happens.

like on sparc64:

cpu0 at mainbus0: SUNW,UltraSPARC-IIIi @ 1280 MHz, UPA id 0
cpu0: 32K instruction (32 b/l), 64K data (32 b/l), 1024K external (64 b/l)



.mrg.