Re: High Memory Address Space

Martin J. Bligh (Martin.Bligh@us.ibm.com)
Fri, 03 May 2002 09:05:05 -0700


> How is the maximum memory address space, per process or for all process,
> using High Memory Suport to 64Gb?

Roughly speaking, the high memory (above 896MB phys) is mapped directly
into user address spaces, mapped a page at a time into the kernel
virtual address space via kmap and friends into a small window.

> Is possible to alocate more than 3GB for one process?

Not really, you could shift the boundary to 3.5Gb or so in theory,
and eek out a little more, but in practice that just makes you
run out of kernel address space instead if you have enough memory
to make it worthwhile (unless you wanted the users pages swapped
out).

M.

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