Bug 5752 - Dual Opteron - Memory missing
Dual Opteron - Memory missing
Status: REJECTED INSUFFICIENT_DATA
Product: Platform Specific/Hardware
Classification: Unclassified
Component: x86-64
i386 Linux
: P2 normal
Assigned To: Andi Kleen
:
Depends on:
Blocks:
  Show dependency treegraph
 
Reported: 2005-12-16 03:51 UTC by Fabio Bettio
Modified: 2006-04-22 12:43 UTC (History)
1 user (show)

See Also:
Kernel Version: 2.6.14
Tree: Mainline
Regression: ---


Attachments

Description Fabio Bettio 2005-12-16 03:51:29 UTC
Distribution: Gentoo
Linux 2.6.14-gentoo-r2 #1 SMP PREEMPT Tue Dec 13 16:36:52 CET 2005 x86_64 Dual
Core AMD Opteron(tm) Processor 265 AuthenticAMD GNU/Linux

Hardware Environment:
Mobo: TYAN S2895A2NRF
CPU: 2X AMD Opteron 265 Dual Core
RAM: 4X 1GB DDr PC3200 ECC Registered
HD: 2X250 GB SATA 7200 rpm
    2X74 GB SATA 10000 rpm
Graphics: 2X ASUS GF7800GTX 256MB PCI-Express

Software Environment:
ANY special env. only the system shell

Problem Description:
The system shows only ~2GB of memory instead of 4GB installed.
I found out that different bootloaders provide different behaviours:


***GRUB

Everything works fine but the memory size is small... 

# free -ml
total used free shared buffers cached
Mem: 2427 487 1939 0 62 294
Low: 2427 487 1939
High: 0 0 0
-/+ buffers/cache: 130 2297
Swap: 7820 62 7758



*** LILO

The memory size is ok

# free -ml
total used free shared buffers cached
Mem: 3942 93 3848 0 15 31
Low: 3942 93 3848
High: 0 0 0
-/+ buffers/cache: 47 3894
Swap: 7820 0 7820

BUT, X freezes the system (without errors, the screen gets black
and all is frozen)

--------------------

I enabled the following kernel parameters:
K8 NUMA Support
Memory Model (Discontiguous Memory)
IOMMU support

I configured the BIOS as follow:
BIOS/Advanced/Hammer Configuration/ Memory Hole
4GB Memory Hole Adjust [AUTO]
  4GB Memory Hole Size (EMPTY)
IOMMU [ENABLED]
Memhole mapping [HARDWARE]

Steps to reproduce:
Comment 1 Andi Kleen 2006-01-30 00:38:11 UTC
Please attach boot.msg for lilo / grub. 

What happens when you try other settings in the BIOS, e.g. other 
settings for memhole mapping and 4GB memory hole adjust?

BIOS/Advanced/Hammer Configuration/ Memory Hole
4GB Memory Hole Adjust [AUTO]
  4GB Memory Hole Size (EMPTY)
IOMMU [ENABLED]
Memhole mapping [HARDWARE]

Comment 2 Adrian Bunk 2006-04-22 12:43:52 UTC
Please reopen this bug if:
- it is still present in kernel 2.6.16 and
- you can provide the requested information.

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