Re: 4Gb ram not showing up

From: Wakko Warner
Date: Mon Jun 04 2007 - 19:18:19 EST


Tom Moore wrote:
> Thank you for the reply back. Your answer makes perfect sense to me,
> and it is what I had suspected but was not sure about. The math seems
> to indicate that 4Gb of ram plus 1Gb of PCI address space equals 5Gb of
> memory space. So it does sound like I should have a larger kernel model.
>
> What confused me the most (and still does), is the help message string
> that is presented for the CONFIG_HIGHMEM4G option:
> "Select this if you have a 32-bit processor and between 1 and 4
> gigabytes of physical RAM."

4 is not between 1 and 4.

> Well that sounds like the amount of memory that I have, so that is what
> I selected.

You should select CONFIG_HIGHMEM64G.

> Also, although I know what PAE stands for, I don't know how to select it
> when building a kernel. Would I get this from the CONFIG_HIGHMEM64G
> option? The help text for that says:
> "Select this if you have a 32-bit processor and more than 4 gigabytes
> of physical RAM."

Personally, I feel the wording should say:
Select this if you have a 32-bit processor and 4 or more gigabytes of
physical RAM.

It may not hurt to say 3 or more, but I'm not that familiar with x86
hardware in regards to memory.

> This does not sound like it applies to my hardware. There is something
> wrong with my understanding, or with these message strings. I am still
> confused.

It does.

Here's my system (4gb of memory):
total used free shared buffers cached
Mem: 3619996 3289352 330644 0 469764 2025416
-/+ buffers/cache: 794172 2825824
Swap: 0 0 0

I know it says 3.6gb of memory, but 4gb is installed. I had 5gb in this
machine and I saw all 5gb. This is a 32-bit dual xeon (12gb max memory)

I would be interested to know where the last 400mb of memory went.

--
Lab tests show that use of micro$oft causes cancer in lab animals
Got Gas???
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/