Re: Allocating more than 890MB in the kernel?

H. Peter Anvin (hpa@zytor.com)
19 Oct 2001 12:59:20 -0700


Followup to: <3BD08207.7090807@interactivesi.com>
By author: Timur Tabi <ttabi@interactivesi.com>
In newsgroup: linux.dev.kernel
>
> > Isn't this solved by just recompiling the kernel with HIGHMEM support?
>
>
> I don't think so. The Red Hat 7.1 kernel is compiled with "4GB" support,
> which apparently is the same as HIGHMEM. We see the 890MB kernel vmalloc
> limit still.
>

That's because you're running out of address space, not memory.
HIGHMEM doesn't do anything for the latter -- it can't. You start
running into a lot of fundamental problems when your memory size gets
in the same (or higher) ballpark than your address space.

The best solution is go buy a 64-bit CPU. There isn't much else you
can do about it.

-hpa

-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt	<amsp@zytor.com>
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