Re: PROBLEM: Linux 2.6.0-test11 only lets me use 1GB out of 2GB ram.

[Nick Piggin <piggin@cyberone.com.au>]

Raul Miller wrote:

>On Wed, Dec 10, 2003 at 11:06:46PM -0600, Donald Maner wrote:
>
>>The kernel you're using WAS compiled with CONFIG_HIGHMEM4G=y, correct?
>>
>
>No.
>
>
>On Thu, Dec 11, 2003 at 04:13:25PM +1100, Nick Piggin wrote:
>
>>Or ARCH=x86_64 ?
>>
>
>Yes.  Well, no... I don't see that option in my .config.  I
>did specify the amd64 bit archictecture, but I don't know
>what that means in .config terms.  Here's what's set under
>"# Processor type and features":
>

This optimises the kernel for your chip when its in 32-bit mode.
make 'ARCH=x64_64' to make a 64-bit kernel, however you would
need a cross compiler.

>
>On Thu, Dec 11, 2003 at 04:48:51PM +1100, Nick Piggin wrote:
>
>>At any rate, Raul, highmem shouldn't hurt your performance significantly
>>with the 2.6 kernel. If it does then send a note to the list.
>>
>
>Ok, I guess I'll try that (tomorrow, unless I hear any better suggestions
>before then).
>
>[I thought highmem was something completely different -- that it declared
>a watermark and memory above that watermark was treated differently.
>However, I guess I understand that this might have the side effect of
>bumping things around such that I get access to the memory.]
>

No you're right, but the kernel tries not to use highmem for data it
accesses a lot. cache and anonymous memory for example.