Re: i686 SMP systems with more then 12 GB ram with 2.4.x kernel ?

From: Mark Zealey (
Date: Wed Jan 02 2002 - 19:17:07 EST

On Thu, Jan 03, 2002 at 12:50:50AM +0100, Harald Holzer wrote:

> Today i checked some memory configurations and noticed that the low
> memory decreases, when i add more memory to the system,
> and the size of reserved memory increases:
> at 1GB ram, are 16,936kB low mem reserved.
> 4GB ram, 72,824kB reserved
> 8GB ram, 142,332kB reserved
> 16GB ram, 269,424kB reserved
> 32GB ram, 532,080kB reserved, usable low mem: 352 MB
> 64GB ram ??
> Which function does the reserved memory fulfill ?
> Is it all for paging ?

Yeah, page tables mostly, they have to be kept in low-mem. It's making struct
page's for every single page in that system, and must be kept in the kernel

I'd doubt if you could get the system to boot at 64 gigs


Mark Zealey

UL++++>$ G!>(GCM/GCS/GS/GM) dpu? s:-@ a16! C++++>$ P++++>+++++$ L+++>+++++$ !E---? W+++>$ N- !o? !w--- O? !M? !V? !PS !PE--@ PGP+? r++ !t---?@ !X---? !R- b+ !tv b+ DI+ D+? G+++ e>+++++ !h++* r!-- y--

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