Re: [Lse-tech] Re: maximum possible memory limit ..

[Andi Kleen]

> > Don't forget that highmem starts to be needed before the 4G boundary.
> > The kernel has only 1GB of virtual space (look for PAGE_OFFSET, which
> > defines it), which means that you start needing to pull all of the
> > highmem trickery before you get to the actual limits.
> 
> It seems I misunderstood the concept of highmem. I thought highmem was
> not needed on 64-bit arches. Thanks for pointing that out to me.

No, your original understandarding was correct. Highmem is not used on 64bit.

-Andi