linux-kernel - Opteron box and 4Gb memory

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20071025230904.03d5f46a@werewolf>
Date:	Thu, 25 Oct 2007 23:09:04 +0200
From:	"J.A. Magallon" <magallon@...zar.es>
To:	"Linux-Kernel, " <linux-kernel@...r.kernel.org>
Subject: Opteron box and 4Gb memory

Hi...

I have some Quad-Opteron boxes with 4Gb memory and two of them are
running two different Linux distros.

Box one sees 4Gb of memory, but box two just sees 3.
Their mtrr setups are different:

one:
[    0.000000] Linux version 2.6.20...
...
[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
[    0.000000]  BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
[    0.000000]  BIOS-e820: 00000000000e6000 - 0000000000100000 (reserved)
[    0.000000]  BIOS-e820: 0000000000100000 - 00000000b7fd0000 (usable)
[    0.000000]  BIOS-e820: 00000000b7fd0000 - 00000000b7fde000 (ACPI data)
[    0.000000]  BIOS-e820: 00000000b7fde000 - 00000000b8000000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
[    0.000000]  BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
[    0.000000]  BIOS-e820: 00000000ff780000 - 0000000100000000 (reserved)
[    0.000000]  BIOS-e820: 0000000100000000 - 0000000145000000 (usable)
[    0.000000] Entering add_active_range(0, 0, 159) 0 entries of 3200 used
[    0.000000] Entering add_active_range(0, 256, 753616) 1 entries of 3200 used
[    0.000000] Entering add_active_range(0, 1048576, 1331200) 2 entries of 3200 
used
[    0.000000] end_pfn_map = 1331200

cat /proc/mtrr:
reg00: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg01: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
reg02: base=0x140000000 (5120MB), size=  64MB: write-back, count=1
reg03: base=0x144000000 (5184MB), size=  16MB: write-back, count=1
reg04: base=0xb8000000 (2944MB), size= 128MB: uncachable, count=1
reg05: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1

two:
Linux version 2.6.22.9...
...
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
 BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000e6000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 00000000b8fd0000 (usable)
 BIOS-e820: 00000000b8fd0000 - 00000000b8fde000 (ACPI data)
 BIOS-e820: 00000000b8fde000 - 00000000b9000000 (ACPI NVS)
 BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
 BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
 BIOS-e820: 00000000ff780000 - 0000000100000000 (reserved)
Entering add_active_range(0, 0, 159) 0 entries of 3200 used
Entering add_active_range(0, 256, 757712) 1 entries of 3200 used
end_pfn_map = 1048576

cicely:~# cat /proc/mtrr
reg00: base=0x00000000 (   0MB), size=2048MB: write-back, count=1
reg01: base=0x80000000 (2048MB), size= 512MB: write-back, count=1
reg02: base=0xa0000000 (2560MB), size= 256MB: write-back, count=1
reg03: base=0xb0000000 (2816MB), size= 128MB: write-back, count=1
reg04: base=0xb8000000 (2944MB), size=  16MB: write-back, count=1


Why ? Is it a bios setup problem ? A kernel problem ?
grep HIGHMEN in configs for both kernels does not give anything, so
I still understand less this thing...

-- 
J.A. Magallon <magallon()unizar!es>     \               Software is like sex:
                                         \         It's better when it's free
MacOS X 10.4.8 Tiger - Darwin Kernel Version 8.8.0 PPC

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/