[Solved] Dualcore Macbook using only one cpu

Question

Hello,
I have a dual core macbook running Arch, default installation with default kernel (64bit). I just noticed that I only have one cpu running, even when I do some cpu-intensive work. Here is the output of /proc/cpuinfo:
└─■ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU T7500 @ 2.20GHz
stepping : 11
cpu MHz : 800.000
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 10
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 nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm dts tpr_shadow vnmi flexpriority
bogomips : 4391.55
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:
processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU T7500 @ 2.20GHz
stepping : 11
cpu MHz : 800.000
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
apicid : 1
initial apicid : 1
fpu : yes
fpu_exception : yes
cpuid level : 10
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 nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm dts tpr_shadow vnmi flexpriority
bogomips : 4390.91
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:
which shows two cpus registered to the system, but when I do top, I get the following output:
top - 00:29:07 up 7:33, 0 users, load average: 0.05, 0.05, 0.05
Tasks: 93 total, 2 running, 91 sleeping, 0 stopped, 0 zombie
Cpu(s): 9.0%us, 4.1%sy, 0.2%ni, 86.1%id, 0.7%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 4020236k total, 1386244k used, 2633992k free, 53056k buffers
Swap: 0k total, 0k used, 0k free, 826672k cached
Which tells me I only have one cpu. Am I doing something wrong? I have cpufreq-utils and laptop-mode running, but I don't think it should affect this. The following is the output of cpufreq-info
└─■ cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to [email protected], please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.20 GHz
available frequency steps: 2.20 GHz, 2.00 GHz, 1.80 GHz, 1.60 GHz, 1.40 GHz, 1.20 GHz, 800 MHz
available cpufreq governors: ondemand, performance
current policy: frequency should be within 800 MHz and 2.20 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 1
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.20 GHz
available frequency steps: 2.20 GHz, 2.00 GHz, 1.80 GHz, 1.60 GHz, 1.40 GHz, 1.20 GHz, 800 MHz
available cpufreq governors: ondemand, performance
current policy: frequency should be within 800 MHz and 2.20 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
and it also shows the two cpus, and cpu1 frequency gets higher when I do cpu intensive work, as it should, but cpu0 always stays at 800MHz. Can anybody help me please? Thanks!
Last edited by kcirick (2011-01-24 15:41:21)

Answer 1

Thanks foutrelis. I installed htop and monitored my cpu usage. It seems to be in working order. When I mentioned "cpu intensive work", it turned out that I was talking about something that was using average 50% on both cores, and assumed that meant one was at 100% and the other was 0% (I have conky tell me the average cpu usage).
Marking this as solved. Thanks again!