Bill Holler wrote:

> I was thinking of adding decision rates to cpudrv kstat.
> Powertop may be better because it would use dtrace probes
> that do not effect performance when not in use.
> 
> Regards,
> Bill
> 
> 
> On 12/04/08 16:58, Raj, Ashok wrote:
>> Should we add some sort of logging facility to powertop
> (maybe it already does?) to get history or log generated with
> decisions to switch pstate/cstate/intr rate or other
> parameters. This will help analyze running different workloads
> and see how our PAD scheduler was good/bad with choices made?

I believe the "dump [count]" option of powertop is what you suggested.

-Aubrey

>> 
>> 
>> 
>> 
>>> -----Original Message-----
>>> From: tesla-dev-bounces at opensolaris.org
> [mailto:tesla-dev-bounces at opensolaris.org] On Behalf Of Bill
>>> Holler
>>> Sent: Thursday, December 04, 2008 12:03 PM
>>> To: tesla-dev at opensolaris.org
>>> Subject: [tesla-dev] Some experiments with C-state
> throttleing based on number of active CPUs
>>> 
>>> Hi Tesla Dev,
>>> 
>>> I have been experimenting not going into C3 or C2 when
>>> the number of non-idle CPUs in the cpu-partion exceeds
>>> a threshold.  This is an attempt to regain the high load
>>> performance. These numbers are on a 2-socket system.
>>> 
>>> With C3 threshold = 40% active and C2 threshold = 60% active
>>> the libmicro fork_1000 benchmark completes in 80/100 the time.
>>> 
>>> With C3 threshold = 20% active and C2 threshold = 30% active
>>> the libmicro fork_1000 benchmark completes in 50/100 the time.
>>> These numbers are still about 80/100 slower than with c-states
>>> totally disabled. 
>>> 
>>> 
>>> I am also going to experiment with cpu idle/wakeup rate.
>>> I suspect this may be more important for performance than
>>> the number of active cpus.
>>> 
>>> Regards,
>>> Bill
>>> _______________________________________________
>>> tesla-dev mailing list
>>> tesla-dev at opensolaris.org
>>> http://mail.opensolaris.org/mailman/listinfo/tesla-dev
>>> 
> 
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