On Sat, Sep 5, 2009 at 9:40 PM, Sebastien Roy<[email protected]> wrote:
> On Sat, 2009-09-05 at 16:31 +0800, Aubrey Li wrote:
>> On Sat, Sep 5, 2009 at 10:59 AM, Sebastien Roy<[email protected]> wrote:
>> > On Sat, 2009-09-05 at 10:38 +0800, Aubrey Li wrote:
>> >  I wonder what changed.
>>
>> to put this simply, the default mode is event driving, which makes the 
>> p-state
>> transition decision by several sampling points. It's more aggressive.
>>
>> "poll-mode" makes the transition decision by a tunable sampling period. The
>> period is 1s on your system (cpu-threshold 1s). It's more stable.
>
> Hmm, is it then possible that when event driven mode is used, powertop
> simply can't observe the lower p-states because of its probe effect?
>

I'm not clear what powertop reports on your system. Assume that you are using
powertop V1.2. Did you see 100% highest p-state residency?

The alternative way is checking the current clock by kstat
$ kstat -i 1 | grep current_clock_Hz

You could check it from time to time (10s or longer maybe), the instance
option(-i) here helps to reduce the load effect.

Need to mention, I upgraded my system(24 logical cores) to b122 just now and
tried powertop in event mode. I saw 100% lowest frequency residency on my side.

-Aubrey
_______________________________________________
indiana-discuss mailing list
[email protected]
http://mail.opensolaris.org/mailman/listinfo/indiana-discuss

Reply via email to