mtrr errors - /proc/mtrr settings on 64 bit systems

toad · 2009-09-02 19:56:09

Hi,

I've got what I think is a very decent system but it underperforms at times quite horrendously In the logs I've come across the following:

Sep  2 15:53:55 deskarch kernel: mtrr: no MTRR for d0000000,10000000 found
Sep  2 15:53:58 deskarch kernel: mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining
Sep  2 15:53:58 deskarch kernel: mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining
Sep  2 15:53:58 deskarch kernel: mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining
Sep  2 15:53:58 deskarch kernel: mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining
Sep  2 15:53:58 deskarch kernel: mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining

Since I am not sure what is at fault here some more info just in case:

cat /proc/mtrr
reg00: base=0x000000000 (    0MB), size= 4096MB, count=1: write-back
reg01: base=0x100000000 ( 4096MB), size= 1024MB, count=1: write-back
reg02: base=0x0c0000000 ( 3072MB), size= 1024MB, count=1: uncachable

cat /proc/cpuinfo 
processor       : 0                               
vendor_id       : GenuineIntel                    
cpu family      : 6                               
model           : 23                              
model name      : Intel(R) Core(TM)2 CPU         E8400  @ 3.00GHz
stepping        : 10                                             
cpu MHz         : 2953.328                                       
cache size      : 6144 KB                                        
physical id     : 0                                              
siblings        : 2                                              
core id         : 0                                              
cpu cores       : 2                                              
apicid          : 0                                              
initial apicid  : 0                                              
fpu             : yes                                            
fpu_exception   : yes                                            
cpuid level     : 13                                             
wp              : yes                                            
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall lm constant_tsc arch_perfmon pebs bts rep_good pni monitor tm2 ssse3 lahf_lm    
bogomips        : 5909.76                                                                                        
clflush size    : 64                                                                                             
cache_alignment : 64                                                                                             
address sizes   : 36 bits physical, 48 bits virtual                                                              
power management:

(same for the second processor)

So I've got a 64 bit system with some memory allocation problem (as far as I can gather). Have any of you got different settings in /proc/mtrr? If so, could you post them so I could try them out?

Naturally I'd also be very interested in any other ideas since mine is nothing but conjecture...

And some more data:

07:00.0 VGA compatible controller: ATI Technologies Inc RV505 [Radeon X1550 Series] (prog-if 00 [VGA controller])
        Subsystem: Giga-byte Technology Device 2164
        Flags: bus master, fast devsel, latency 0, IRQ 16
        Memory at d0000000 (64-bit, prefetchable) [size=256M]
        Memory at febe0000 (64-bit, non-prefetchable) [size=64K]
        I/O ports at e000 [size=256]
        Expansion ROM at febc0000 [disabled] [size=128K]
        Capabilities: <access denied>

Last edited by toad (2009-09-02 20:04:09)

Arch Linux

#1 2009-09-02 19:56:09

mtrr errors - /proc/mtrr settings on 64 bit systems

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