Relocating mem_map to the upper end of main memory?

Josef Moellers (josef.moellers@pdb.siemens.de)
Fri, 08 Oct 1999 12:54:44 +0200


Hi,

We have experienced some problems with large memories:
at around a memory size of 800MB, the mem_map has grown so large that it
extends above the 16MB boundary, leaving very little memory for those
kernel components that request ISA-DMA-able memory (AAMOF only base
memory is left).

I have attempted to relocate the mem_map to "the other end" of memory,
i.e. aligning it with end_mem rather than start_mem. It looked as if it
was feasable, but the system choked at some time, causing me to wonder:

Question: Is there any reason why the mem_map must be at the lower end
of memory or can I go ahead and relocate it to the upper end? The
relocation is pretty straight-forward, but I am unsure of the over-all
(side-)effects that it may cause and additional changes that might be
required.

BTW Please CC me on your reply.

Josef

-- 
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