Re: Byte article - 64 bit Unix (fwd)

Jim Nance (
Sat, 26 Oct 1996 20:14:03 -0400 (EDT)

Forwarded message:

> > I think we need to distinguish a few things about 64 bit OS's...
> >
> > Does the user address space have 64 bit addressability?
> In theory Linux/Alpha could eventually give the user 62 bits of VM
> address space. The current CPU implementations limit us to 43 bits.
> > Do file offsets have 64 bit addressability?
> Yes, off_t is 64 bits. None of the underlying filesystems currently
> support files that big, but the VFS layer does not disallow it.

He is right. I guess I should have said that the capability of Linux/Alpha
was significantly greater than 32 bits in these areas, which is not the
same as being 64 bits. I guess I can be excused though. Digital says
their Unix is 64 bits, and they have the 43 bit address limit too.