Bug 148330

Summary: frequency scaling is not using all throttling states
Product: [openSUSE] SUSE Linux 10.1 Reporter: k. t. <cooling.crystals>
Component: KernelAssignee: E-mail List <kernel-maintainers>
Status: RESOLVED INVALID QA Contact: E-mail List <qa-bugs>
Severity: Normal    
Priority: P5 - None    
Version: Beta 3   
Target Milestone: ---   
Hardware: i686   
OS: Other   
Whiteboard:
Found By: Other Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description k. t. 2006-02-06 08:50:59 UTC
kbeta@kohvi:~> cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T4
states:
    T0:                  00%
    T1:                  12%
    T2:                  25%
    T3:                  37%
   *T4:                  50%
    T5:                  62%
    T6:                  75%
    T7:                  87%

kbeta@kohvi:~> cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 13
model name      : Intel(R) Pentium(R) M processor 1.73GHz
stepping        : 8
cpu MHz         : 800.000
cache size      : 2048 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx est tm2
bogomips        : 1603.11

Suse 10.1beta3 (suse 10.0 also) only uses 800MHz or 1.73GHz.
I could be totally wrong about this but dmesg says:
ACPI: CPU0 (power states: C1[C1] C2[C2] C3[C3])
ACPI: Processor [CPU0] (supports 8 throttling states)
Comment 1 Andreas Kleen 2006-02-06 09:03:28 UTC
Throttling is only for when your CPU overheats. Hopefully never happens.
When it happens it's not controlled by software, but by the CPU itself.