It seems my laptop (an Acer Aspire One AOA150) runs out of MTRRs at boot. I've done some googling on the problem and read that people recommend turning on MTRR sanitizing to fix it, however, it still occurs. I'm running Arch Linux (but that shouldn't matter). You can see that I have enabled MTRR sanitization here:
[chris@helios ~]$ zgrep 'SANITIZER' /proc/config.gz
CONFIG_MTRR_SANITIZER=y
CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1
Here is my relevant system info:
uname -a:
Linux helios 2.6.38-aao-light #1 SMP PREEMPT Fri Apr 1 03:02:37 BST 2011 i686 Intel(R) Atom(TM) CPU N270 @ 1.60GHz GenuineIntel GNU/Linux
dmesg potential warnings:
[ 0.000000] Notice: NX (Execute Disable) protection missing in CPU!
[ 0.000000] RCU-based detection of stalled CPUs is disabled.
[ 0.000000] Verbose stalled-CPUs detection is disabled.
[ 0.157222] ACPI Error: [CAPB] Namespace lookup failure, AE_ALREADY_EXISTS (20110112/dsfield-143)
[ 0.157393] ACPI Error: Method parse/execution failed [\_SB_.PCI0._OSC] (Node f682fca8), AE_ALREADY_EXISTS (20110112/psparse-536)
[ 0.157578] ACPI: Marking method _OSC as Serialized because of AE_ALREADY_EXISTS error
[ 0.160212] pci 0000:00:1b.0: PME# disabled
[ 0.160354] pci 0000:00:1c.0: PME# disabled
[ 0.160498] pci 0000:00:1c.1: PME# disabled
[ 0.160642] pci 0000:00:1c.2: PME# disabled
[ 0.160787] pci 0000:00:1c.3: PME# disabled
[ 0.161441] pci 0000:00:1d.7: PME# disabled
[ 0.162043] pci 0000:00:1f.2: PME# disabled
[ 0.162677] pci 0000:02:00.0: PME# disabled
[ 0.166197] pci 0000:00:1e.0: bridge window [io 0xf000-0x0000] (disabled)
[ 0.166207] pci 0000:00:1e.0: bridge window [mem 0xfff00000-0x000fffff] (disabled)
[ 0.166219] pci 0000:00:1e.0: bridge window [mem 0xfff00000-0x000fffff pref] (disabled)
[ 0.167559] ACPI Error: [CAPB] Namespace lookup failure, AE_ALREADY_EXISTS (20110112/dsfield-143)
[ 0.167729] ACPI Error: Method parse/execution failed [\_SB_.PCI0._OSC] (Node f682fca8), AE_ALREADY_EXISTS (20110112/psparse-536)
[ 0.168113] ACPI Error: [CAPB] Namespace lookup failure, AE_ALREADY_EXISTS (20110112/dsfield-143)
[ 0.168279] ACPI Error: Method parse/execution failed [\_SB_.PCI0._OSC] (Node f682fca8), AE_ALREADY_EXISTS (20110112/psparse-536)
[ 0.178246] ACPI: PCI Interrupt Link [LNKE] (IRQs 3 4 5 7 9 10 11 12) *0, disabled.
[ 0.178612] ACPI: PCI Interrupt Link [LNKF] (IRQs 3 4 5 7 9 10 11 12) *0, disabled.
[ 0.179008] ACPI: PCI Interrupt Link [LNKG] (IRQs 3 4 5 7 9 10 11 12) *0, disabled.
[ 0.179375] ACPI: PCI Interrupt Link [LNKH] (IRQs 3 4 5 7 9 10 11 12) *0, disabled.
[ 0.190814] pnp 00:04: [irq 0 disabled]
[ 0.235056] pci 0000:00:1e.0: bridge window [io disabled]
[ 0.235135] pci 0000:00:1e.0: bridge window [mem disabled]
[ 0.235212] pci 0000:00:1e.0: bridge window [mem pref disabled]
[ 0.254489] Marking TSC unstable due to TSC halts in idle states deeper than C2
[ 0.332589] [drm] MTRR allocation failed. Graphics performance may suffer.
zgrep -i MTRR /proc/config.gz
CONFIG_MTRR=y
CONFIG_MTRR_SANITIZER=y
CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=2
/proc/iomem:
00000000-0000ffff : reserved
00010000-0009fbff : System RAM
0009fc00-0009ffff : reserved
000a0000-000bffff : PCI Bus 0000:00
000a0000-000bffff : Video RAM area
000c0000-000c7fff : Video ROM
000cf000-000cffff : Adapter ROM
000e0000-000fffff : reserved
000f0000-000fffff : System ROM
00100000-3f375fff : System RAM
01000000-0148cffe : Kernel code
0148cfff-015e417f : Kernel data
01646000-016b2fff : Kernel bss
3f376000-3f3befff : reserved
3f3bf000-3f46cfff : System RAM
3f46d000-3f4befff : ACPI Non-volatile Storage
3f4bf000-3f4effff : System RAM
3f4f0000-3f4fefff : ACPI Tables
3f4ff000-3f4fffff : System RAM
3f500000-3fffffff : reserved
40000000-febfffff : PCI Bus 0000:00
40000000-4fffffff : 0000:00:02.0
50000000-50ffffff : PCI Bus 0000:01
51000000-520fffff : PCI Bus 0000:02
51000000-5100ffff : 0000:02:00.0
51000000-5100ffff : r8169
51010000-51010fff : 0000:02:00.0
51010000-51010fff : r8169
51020000-5103ffff : 0000:02:00.0
52100000-530fffff : PCI Bus 0000:03
53100000-540fffff : PCI Bus 0000:04
54100000-551fffff : PCI Bus 0000:04
55200000-562fffff : PCI Bus 0000:03
55200000-5520ffff : 0000:03:00.0
55200000-5520ffff : ath5k
56300000-572fffff : PCI Bus 0000:02
57300000-583fffff : PCI Bus 0000:01
58400000-5847ffff : 0000:00:02.1
58480000-584fffff : 0000:00:02.0
58500000-5853ffff : 0000:00:02.0
58540000-58543fff : 0000:00:1b.0
58540000-58543fff : ICH HD audio
58544400-585447ff : 0000:00:1d.7
58544400-585447ff : ehci_hcd
58545000-58545fff : Intel Flush Page
e0000000-efffffff : PCI MMCONFIG 0000 [bus 00-ff]
e0000000-efffffff : reserved
e0000000-efffffff : pnp 00:01
fec00000-fec00fff : reserved
fec00000-fec003ff : IOAPIC 0
fed00000-fed003ff : HPET 0
fed14000-fed19fff : reserved
fed14000-fed17fff : pnp 00:01
fed18000-fed18fff : pnp 00:01
fed19000-fed19fff : pnp 00:01
fed1c000-fed1ffff : reserved
fed1c000-fed1ffff : pnp 00:01
fee00000-fee00fff : Local APIC
fee00000-fee00fff : reserved
fee00000-fee00fff : pnp 00:01
fff00000-ffffffff : reserved
/proc/cpuinfo:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 28
model name : Intel(R) Atom(TM) CPU N270 @ 1.60GHz
stepping : 2
cpu MHz : 1600.000
cache size : 512 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm dts
bogomips : 3192.06
clflush size : 64
cache_alignment : 64
address sizes : 32 bits physical, 32 bits virtual
power management:
processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 28
model name : Intel(R) Atom(TM) CPU N270 @ 1.60GHz
stepping : 2
cpu MHz : 1600.000
cache size : 512 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 1
initial apicid : 1
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm dts
bogomips : 3191.83
clflush size : 64
cache_alignment : 64
address sizes : 32 bits physical, 32 bits virtual
power management:
/proc/mtrr:
reg00: base=0x0fffe0000 ( 4095MB), size= 128KB, count=1: write-protect
reg01: base=0x0fffc0000 ( 4095MB), size= 128KB, count=1: uncachable
reg02: base=0x000000000 ( 0MB), size= 512MB, count=1: write-back
reg03: base=0x020000000 ( 512MB), size= 512MB, count=1: write-back
reg04: base=0x03f800000 ( 1016MB), size= 8MB, count=1: uncachable
reg05: base=0x03f600000 ( 1014MB), size= 2MB, count=1: uncachable
reg06: base=0x03f500000 ( 1013MB), size= 1MB, count=1: uncachable
reg07: base=0x000000000 ( 0MB), size= 128KB, count=1: uncachable
lshw:
helios
description: Computer
product: AOA150 (Napa_Fab5)
vendor: Acer
version: 1
serial: LUS050A0748370F93B2535
width: 32 bits
capabilities: smbios-2.4 dmi-2.4
configuration: boot=normal family=Intel_Mobile sku=Napa_Fab5 uuid=E081A8C2-6CE0-D411-BB0B-001E68E42BCA
*-core
description: Motherboard
vendor: Acer
physical id: 0
version: Base Board Version
serial: Base Board Serial Number
slot: Base Board Chassis Location
*-firmware
description: BIOS
vendor: Acer
physical id: 0
version: v0.3301
date: 05/09/2008
size: 1MiB
capabilities: pci upgrade shadowing cdboot bootselect socketedrom edd int13floppynec int13floppytoshiba int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int9keyboard int10video acpi usb
*-memory
description: System Memory
physical id: 14
slot: System board or motherboard
size: 1GiB
*-bank:0
description: DIMM DDR2 Synchronous 533 MHz (1.9 ns)
product: HYMP164S64CP6-Y5
vendor: Hynix Semiconductor (Hyundai Electronics)
physical id: 0
serial: 0x00000000
slot: J2
size: 512MiB
width: 64 bits
clock: 533MHz (1.9ns)
*-bank:1
description: DIMM DDR2 Synchronous 533 MHz (1.9 ns)
product: HYMP164S64CP6-Y5
vendor: Hynix Semiconductor (Hyundai Electronics)
physical id: 1
serial: 0x00002337
slot: J6H2
size: 512MiB
width: 64 bits
clock: 533MHz (1.9ns)
*-cpu
description: CPU
product: Intel(R) Atom(TM) CPU N270 @ 1.60GHz
vendor: Intel Corp.
physical id: 1c
bus info: cpu@0
version: 6.12.2
serial: 0001-06C2-0000-0000-0000-0000
slot: CPU
size: 800MHz
capacity: 1600MHz
width: 32 bits
clock: 533MHz
capabilities: fpu fpu_exception wp vme de tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm cpufreq
configuration: id=0
*-cache:0
description: L2 cache
physical id: 1d
slot: Unknown
size: 512KiB
capacity: 512KiB
capabilities: synchronous internal write-back unified
*-cache:1
description: L1 cache
physical id: 1e
slot: Unknown
size: 32KiB
capacity: 32KiB
capabilities: synchronous internal write-back instruction
*-logicalcpu:0
description: Logical CPU
physical id: 0.1
width: 32 bits
capabilities: logical
*-logicalcpu:1
description: Logical CPU
physical id: 0.2
width: 32 bits
capabilities: logical
*-pci
description: Host bridge
product: Mobile 945GME Express Memory Controller Hub
vendor: Intel Corporation
physical id: 100
bus info: pci@0000:00:00.0
version: 03
width: 32 bits
clock: 33MHz
configuration: driver=agpgart-intel
resources: irq:0
*-display:0
description: VGA compatible controller
product: Mobile 945GME Express Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 03
width: 32 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:16 memory:58480000-584fffff ioport:60c0(size=8) memory:40000000-4fffffff memory:58500000-5853ffff
*-display:1 UNCLAIMED
description: Display controller
product: Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2.1
bus info: pci@0000:00:02.1
version: 03
width: 32 bits
clock: 33MHz
capabilities: pm bus_master cap_list
configuration: latency=0
resources: memory:58400000-5847ffff
*-multimedia
description: Audio device
product: N10/ICH 7 Family High Definition Audio Controller
vendor: Intel Corporation
physical id: 1b
bus info: pci@0000:00:1b.0
version: 02
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list
configuration: driver=HDA Intel latency=0
resources: irq:45 memory:58540000-58543fff
*-pci:0
description: PCI bridge
product: N10/ICH 7 Family PCI Express Port 1
vendor: Intel Corporation
physical id: 1c
bus info: pci@0000:00:1c.0
version: 02
width: 32 bits
clock: 33MHz
capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:40 ioport:5000(size=4096) memory:57300000-583fffff ioport:50000000(size=16777216)
*-pci:1
description: PCI bridge
product: N10/ICH 7 Family PCI Express Port 2
vendor: Intel Corporation
physical id: 1c.1
bus info: pci@0000:00:1c.1
version: 02
width: 32 bits
clock: 33MHz
capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:41 ioport:3000(size=8192) memory:56300000-572fffff ioport:51000000(size=17825792)
*-network DISABLED
description: Ethernet interface
product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:02:00.0
logical name: eth0
version: 02
serial: 00:1e:68:e4:2b:ca
size: 10Mbit/s
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
Best Answer
Thanks to harrymc, I discovered that you can actually rewrite /proc/mtrr. I put the following in /etc/rc.local, rebooted, and my MTRR table was correct.
Also, after talking to a few people that are involved with kernel development, I have been informed that
CONFIG_MTRR_SANITIZERhas been broken for the past few kernels, hence why it worked for others in the past.