KERNELBASE & large memory systems

Dan Malek dan at
Tue Jan 22 07:38:38 EST 2002

Mark Pilon wrote:

> I've heard that one shouldn't modify the definition of KERNELBASE
> as it screws up the MM code;

That was true until yesterday.  Matt Porter checked in some configuration
changes that if you know what you are doing will change the virtual
mapping windows on most processors (not 4xx or 8xx yet).  They are
in the linuxppc_2_4_devel kernel.

> I'm wondering how people out there are handling designing systems
> (and getting linux running) on large pools of memory -- like
> 1 - 2 Gb or so.

The only general answer to that question is the solution depends upon
your configuration.  A combination of highmem and kernel address base
changes are used.  This will also affect drivers if you have some custom
application and you are trying to use a driver that makes assumptions
about the "normal" kernel mapping.

The "know what you are doing" is critical to your success :-).

Good Luck.

	-- Dan

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