[gentoo-user] Only 4 of 8 GB usable

[Alex Schuster]

Hi there!

So I installed another 4 GiB RAM into a Gentoo amd64 system that had 4 GiB
already. But it still sees only 4 GiB, not 8 GiB:

leela ~ # uname -a
Linux leela 3.6.11-gentoo #3 SMP Mon Feb 4 15:37:48 CET 2013 x86_64 AMD
A6-3500 APU with Radeon(tm) HD Graphics AuthenticAMD GNU/Linux 

leela ~ #
free -m total       used       free     shared    buffers     cached
Mem:          3688       3269        419          0        108       1050
-/+ buffers/cache:       2110       1577
Swap:         2047         54       1993

Huh? Any idea why this is? The BIOS shows the full 8GiB, and lshw finds
it. dmidecode shows that 8G should work:

leela ~ # dmidecode -t 16
# dmidecode 2.11
SMBIOS 2.7 present.

Handle 0x0008, DMI type 16, 23 bytes
Physical Memory Array
        Location: System Board Or Motherboard
        Use: System Memory
        Error Correction Type: None
        Maximum Capacity: 8 GB
        Error Information Handle: Not Provided
        Number Of Devices: 2

In case this helps, I uploaded the outputs of dmesg [1], lshw -c memory
[2] and full dmidecode output [3]. The dmesg output is somewhat weird
though, it has several 'vmalloc: allocation failure: 0 bytes' entries. I
suspected those were causing the problem, but I found that I needed to
activate CONFIG_KALLSYMS=y, and they are gone. But still only 4 GiB RAM.
The system is using an old kernel right now, so I cannot get the current
dmesg, sorry for this.

Probably related: Since I inserted this 2nd RAM module, wakeup
from hibernate-ram does no longer work.

Does this ring any bells? I'm out of ideas. Except than pulling out the 4
GB, or trying another mainboard.

[1] http://www.wonkology.org/tmp/lshw.txt
[2] http://www.wonkology.org/tmp/dmesg.txt
[3] http://www.wonkology.org/tmp/dmidecode.txt

	Wonko