From: Andreas Beck <becka@rz.uni-duesseldorf.de>
  To  : ggi-develop@eskimo.com
  Date: Sat, 14 Aug 1999 12:35:03 +0200

Re: GGI and XFree86 and stuff

> > You can use the G200-GLX technique of
> > reserving memory on bootup specifically for KGIcon, for example
> > 'mem=120M' if you have 128MB of RAM.  Then you have a guaranteed 8MB for
> > KGIcon to play with.  Anything should be faster than ioctl...

First: It is usually not an issue to allocate much memory at some time.

But I'll answer your questions anyway:

> 1. Does linux have calls to identify the physical top of memory, and
> the linux usable top of memory, and

It has, but that's not what one usually does

> 2. Does linux have a call to increase the linux top of memory mark?

Drivers that need big contigous memory areas allocated do so at boot time
by increasing the "memory-in-use" pointer. So these areas grow upward.

> Lets say you have two drivers, each of which needs memory pre-allocated
> for it in this manner. You'd want the first to say "I'm grabbing
> 8 of the spare 12 megs" in a way that lets the second see 4 megs
> of unclaimed space for it to use.

First come, first serve. But a driver that needs > 1 Meg continuously
allocated is broken IMHO, except maybe on a unified memory architecture,
where it of course makes sense to claim video memory :-).

CU, ANdy

-- 
= Andreas Beck                    |  Email :  <andreas.beck@ggi-project.org> =