Re: Memory in Kernel space

Leonard N. Zubkoff (lnz@dandelion.com)
Fri, 31 May 1996 18:31:53 -0700


Date: Fri, 31 May 1996 20:40:48 -0400
From: "Michael K. Johnson" <johnsonm@nigel.vnet.net>

"Leonard N. Zubkoff" writes:
> From: Paul Gortmaker <gpg109@rsphy6.anu.edu.au>
> Date: Fri, 31 May 1996 17:02:55 +1000 (EST)
>
> Wow. If you need that much, then you are better off not letting the
> kernel have it in the first place. Simply boot with "mem=7m" and
> you can meddle with the upper 25MB as you see fit. The kernel won't
> touch it, and you don't need to futz about with kmalloc().
>
>I don't think it's quite that simple. I tried this once, and if I recall
>correctly, the memory above the mem= value won't be mapped at all and the
>kernel will fault trying to access it. There probably is a way, but it's more
>complicated than this.

The memory will get mapped in if you vremap() it in, won't it?
vremap is supposed to take an offset greater than the high end
of memory and a length and return a virtual address with all
that area mapped in.

No idea. I've never used vremap.

Leonard