Subject: Re: bootstrap page allocation - proposed change
To: Matthias Drochner <>
From: David Brownlee <>
List: tech-kern
Date: 12/17/1999 15:06:31
On Fri, 17 Dec 1999, Matthias Drochner wrote:

> said:
> > Hmm.  Is there any reason why the kernel has to be resident in the
> > sub-16M "prime real estate" on large-memory x86 systems? 
> Simplicity I think.
> It would need some nasty runtime decisions to make one kernel
> run on small and large memory systems. The bootloader is
> affected too.
> Also, the kernel not following the ISA hole would imply
> another memory fragment, slowing down vm_page lookups.
> (Don't know how much this matters.)

	There are already two free memory lists (below 16MB and
	above), so if the kernel could be loaded exactly above
	16MB (on machines that have enough memory) you would
	gain the abiliry to load kernels >16MB, plus you have
	more pages on the <16MB list, which is always a good thing
	for ISA devices performing DMA.

	Presumably you could put pretty much all the magic into the