[gentoo-user] Kernel freezes

[Alexander Puchmayr]

Hi there!

This week I've tried to setup a home-server, but the system is highly 
instable. The first symptoms were lots of page allocation errors, which 
disappeared after setting the internal memory allocator from SLUB to SLAB 
and increasing the min_free_kbytes in /proc/sys/vm from 8MB to 20MB. 

The machine is a AMD Athlon64X2 5050e on a asus M3A78-Pro board with 2x2GB 
RAM. I'm using kernel 2.6.29.4 (vanilla, but the result is the same as 
using 2.6.29-gentoo-r5), and I also upgraded the board's BIOS to the latest 
version (which is 0902)

But still the system freezes after some hours. It just freezes. Console is 
dead, no entry in the logs, no network connectivity, even sysrq doesn't 
seem to do anything. The worst thing is I don't even have an idea what the 
error could be, and in the rare situations when it crashed and the console 
was not blanked, I only see the end of a stack trace, and the intresting 
parts are scrolled out (and I can't scroll back as the console is 
absolutely dead :-(    ) The only button that is still working is the reset 
button, and after rebooting the log does't tell anything (just ends without 
any message)

I inspected my dmesg-output right after booting more precisely, and I've 
found some strange entries which could indicate a problem. What do you 
think about them?

[    0.000000] ACPI Warning (tbfadt-0568): 32/64X length mismatch in 
Gpe0Block: 64/32 [20081204]
[    0.000000] FADT: X_PM1a_EVT_BLK.bit_width (16) does not match 
PM1_EVT_LEN (4)
...
[    0.000000] 4 Processors exceeds NR_CPUS limit of 2
[    0.000000] SMP: Allowing 2 CPUs, 0 hotplug CPUs
...
[    0.000999] Aperture pointing to e820 RAM. Ignoring.
[    0.000999] Your BIOS doesn't leave a aperture memory hole
[    0.000999] Please enable the IOMMU option in the BIOS setup
[    0.000999] This costs you 64 MB of RAM
[    0.000999] Mapping aperture over 65536 KB of RAM @ 20000000
[    0.000999] PM: Registered nosave memory: 0000000020000000 - 
0000000024000000
...
[    0.099055] mtrr: your CPUs had inconsistent fixed MTRR settings
[    0.099059] mtrr: probably your BIOS does not setup all CPUs.
[    0.099116] mtrr: corrected configuration.
...
[    0.151260] PCI-DMA: Disabling AGP.
[    0.151260] PCI-DMA: aperture base @ 20000000 size 65536 KB
[    0.151260] PCI-DMA: using GART IOMMU.
[    0.151260] PCI-DMA: Reserving 64MB of IOMMU area in the AGP aperture
...
[    0.163241] system 00:09: iomem range 0xfec00000-0xfec00fff has been 
reserved
[    0.163305] system 00:09: iomem range 0xfee00000-0xfee00fff has been 
reserved
[    0.163365] system 00:0a: ioport range 0x4d0-0x4d1 has been reserved
[    0.163422] system 00:0a: ioport range 0x40b-0x40b has been reserved
[    0.163480] system 00:0a: ioport range 0x4d6-0x4d6 has been reserved
[    0.163537] system 00:0a: ioport range 0xc00-0xc01 has been reserved
[    0.163595] system 00:0a: ioport range 0xc14-0xc14 has been reserved
[    0.163653] system 00:0a: ioport range 0xc50-0xc51 has been reserved
[    0.163711] system 00:0a: ioport range 0xc52-0xc52 has been reserved
[    0.163769] system 00:0a: ioport range 0xc6c-0xc6c has been reserved
[    0.163827] system 00:0a: ioport range 0xc6f-0xc6f has been reserved
[    0.163885] system 00:0a: ioport range 0xcd0-0xcd1 has been reserved
[    0.163942] system 00:0a: ioport range 0xcd2-0xcd3 has been reserved
[    0.163999] system 00:0a: ioport range 0xcd4-0xcd5 has been reserved
[    0.164070] system 00:0a: ioport range 0xcd6-0xcd7 has been reserved
[    0.164127] system 00:0a: ioport range 0xcd8-0xcdf has been reserved
[    0.164184] system 00:0a: ioport range 0x800-0x89f has been reserved
[    0.164241] system 00:0a: ioport range 0xb00-0xb3f has been reserved
[    0.164305] system 00:0a: ioport range 0x900-0x90f has been reserved
[    0.164363] system 00:0a: ioport range 0x910-0x91f has been reserved
[    0.164421] system 00:0a: ioport range 0xfe00-0xfefe has been reserved
[    0.164480] system 00:0a: iomem range 0xffb80000-0xffbfffff has been 
reserved
[    0.164538] system 00:0a: iomem range 0xfec10000-0xfec1001f has been 
reserved
[    0.164598] system 00:0c: ioport range 0xe00-0xe0f has been reserved
[    0.164656] system 00:0c: ioport range 0xe80-0xe8f has been reserved
[    0.164713] system 00:0c: ioport range 0xf40-0xf4f has been reserved
[    0.164771] system 00:0c: ioport range 0xa30-0xa3f has been reserved
[    0.164830] system 00:0d: iomem range 0xe0000000-0xefffffff has been 
reserved
[    0.164890] system 00:0e: iomem range 0x0-0x9ffff could not be reserved
[    0.164947] system 00:0e: iomem range 0xc0000-0xcffff has been reserved
[    0.165018] system 00:0e: iomem range 0xe0000-0xfffff could not be 
reserved
[    0.165076] system 00:0e: iomem range 0x100000-0xdfffffff could not be 
reserved
[    0.165158] system 00:0e: iomem range 0xfec00000-0xffffffff could not be 
reserved
...
[   21.298450] ACPI: I/O resource piix4_smbus [0xb00-0xb07] conflicts with 
ACPI region SOR1 [0xb00-0xb0f]
[   21.298454] ACPI: Device needs an ACPI driver
[   21.298461] piix4_smbus 0000:00:14.0: SMBus Host Controller at 0xb00, 
revision 0
...
[   73.861479] ACPI: I/O resource it87 [0xe85-0xe86] conflicts with ACPI 
region HWRE [0xe85-0xe86]
[   73.861483] ACPI: Device needs an ACPI driver

Whats does this message "4 Processors exceeds NR_CPUS" say? the system is a 
Dual-Core AMD Athlon64 5050e, AFAIK it has two cores and nothing more. The 
mttr-Message later also indicate that there could be more than 2 CPUs 
available. wondering...

The next thing which seems somewhat strange to me is the AGP aperture and 
the IOMMU. The Mainboard does not have an AGP port, nor does the bios have 
any option to enable. The only thing I can set is the size of the memory 
reservered for the onboad video card, which I set to the smallest value of 
32MB as the machine will usually not even have a display.

The iomem-range reservation errors at the end? Harmful or not?

The last messages come after loading the hw-sensors modules it87.ko and 
i2c_piix4.

Thanks in advance for suggestions
	Alex