Author: Jonathan Hudson Date: To: hampshire Subject: Re: [Hampshire] How to tell how much memory?
On Sat, 14 Jul 2007 18:18:37 +0100
"Victor Churchill" <victorchurchill@???> wrote:
> Hi all, hope the barbie is going/went well ;-)
>
> Here's a funny thing.
> Acer box from a reputable source; 1 GB memory ordered, 1 GB on the
> delivery note, 1GB on the label on the front of the PC.
> BIOS says Total memory 1048576K.
> On booting up, the initial screen (which only shows for a couple of
> seconds) says Memory Testing... 104xxxxx OK. (didn't have time to get
> it fully.)
> I have just had the side off the box for cleaning and it appears to be
> fitted with two identical memory modules each labelled 512 MB.
>
> But ...
> memtest says it is testing 768 MB.
> 'top' says 769500 K.
> System Monitor 751.5 MB.
> /proc/meminfo 769500 .
> dmesg : 762904K/786368K total.
>
> All I can think of is that one of my mem sticks is faulty and thinks
> it is 512 MB, and reports this, but in fact has 'lost' half of it
> (address line stuck?)
>
> Any clues? I think the m/c may still be under warranty, under 1 yr
> old, but I'm reluctant to send it away and anyway I had to peel off
> the warranty sticker to take the side off. (It really did need a clean
> up inside; I live/work in a rather dusty old-house environment and
> there are building works in progress.)
>
> cheers all,
>
> victor
>
You have a kernel build with the (old) <1G memory model. In this mode
Linux does only see 768K.
You need to build the kernel with 1+3 or 2+2 (mapping of VM between
kernel and user space) or whatever its called.
