Re: question about sparc 64-bit user land

[Jeff Garzik <jgarzik@mandrakesoft.com>]

Felix von Leitner wrote:
> 
> My understanding is that there is no 64-bit user land support for
> UltraSPARC, although the kernel runs in 64-bit mode.  Is that correct?
> If yes: why is that (still) so?

sparc64 has an in-kernel thunk layer that lets it run sparc32 binaries,
and a sparc32 userland.

Presumeably the standard benefits apply for 32 over 64 bits, such as
lower I-cache usage and smaller programs overall.  Though most
Linux/Unix applications seem to work ok on 64-bit, (a) some don't and
(b) few apps actually take good advantage of 64-bit machine int and
address space.

Of course, all that said, coming from an Alpha AXP background I prefer
64-bit userland ;-)

	Jeff


-- 
Jeff Garzik      | "I went through my candy like hot oatmeal
Building 1024    |  through an internally-buttered weasel."
MandrakeSoft     |             - goats.com