Re: Unified tracing buffer

From: Masami Hiramatsu
Date: Tue Sep 23 2008 - 15:02:48 EST


Hi Thomas,

Thomas Gleixner wrote:
>
> Do you have C-States enabled on that machine ?
>
> ls /sys/devices/system/cpu/cpu0/cpuidle/
>
> has it more than a state0 entry ?

Yes, there are state0 to state3
# ls /sys/devices/system/cpu/cpu0/cpuidle/
state0 state1 state2 state3

> If yes, please do:
>
> cat /sys/devices/system/cpu/cpu0/cpuidle/stateX/usage
>
> where X is the highest number in there.

# cat /sys/devices/system/cpu/cpu0/cpuidle/state3/usage
171210

>
> cat /proc/acpi/processor/CPU0/power
>
> might be useful as well.

# cat /proc/acpi/processor/CPU0/power
active state: C0
max_cstate: C8
bus master activity: 00000000
maximum allowed latency: 2000000000 usec
states:
C1: type[C1] promotion[--] demotion[--] latency[001] usage[00000016] duration[00000000000000000000]
C2: type[C2] promotion[--] demotion[--] latency[001] usage[00037969] duration[00000000000024288003]
C3: type[C3] promotion[--] demotion[--] latency[057] usage[00171818] duration[00000000001881257636]

Could these help you?

Thank you,

>
> Thanks,
>
> tglx

--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@xxxxxxxxxx

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