Re: [PATCH] Updated: Dynamic Tick version 050408-1 - C-state measures

Tony Lindgren
2005-04-20T20:01:09Z

* Pavel Machek <pavel@suse.cz> [050419 14:10]:
> Hi!
>
> > The machine is a Pentium M 2.00 GHz, supporting C0-C4 processor power states.
> > The machine run at 2.00 GHz all the time.
> ..
> > _passing bm_history=0xFFFFFFFF (default) to processor module:_
> >
> > Average current the last 470 seconds: *1986mA* (also measured better
> > values ~1800, does battery level play a role?!?)
>
> Probably yes. If voltage changes, 2000mA means different ammount of power.

Thomas, thanks for doing all the stats and patches to squeeze some
real power savings out of this! :)

We should display both average mA and average Watts with pmstats.
BTW, I've posted Thomas' version of pmstats as pmstats-0.2.gz to
muru.com also.

> > (cmp. ftp://ftp.suse.com/pub/people/trenn/dyn_tick_c_states/measures_C4_machine/1000_HZ_bm_history_FFFFFFFF)
> >
> >
> > _passing bm_history=0xFF to processor module:_
> >
> > Average current the last 190 seconds: *1757mA*
> > (cmp. ftp://ftp.suse.com/pub/people/trenn/dyn_tick_c_states/measures_C4_machine/1000_HZ_bm_history_FF)
> > (Usage count could be bogus, as some invokations could not succeed
> > if bm has currently been active).
>
> Ok.
>
> > idle_ms == 100, bm_promote_bs == 30
> > Average current the last 80 seconds: *1466mA*
> > (cmp.
> > ftp://ftp.suse.com/pub/people/trenn/dyn_tick_c_states/measures_C4_machine/tony_dyn_tick_processor_idle_100_bm_30)
>
> Very nice indeed. That seems like ~5W saved, right? That might give
> you one more hour of battery life....

Depending on your battery capacity. But looking at the average Watts
on the first 8 lines of the two stats above:

1000_HZ_bm_history_FFFFFFFF:
(21.43 + 23.32 + 23.32 + 21.71 + 21.71 + 23.84 + 23.84 + 22.62) / 8
= 22.724W

tony_dyn_tick_processor_idle_100_bm_30:
(16.07 + 16.07 + 16.00 + 16.00 + 16.08 + 16.08 + 16.29 + 16.29) / 8
= 16.11W

And then comparing these two:
22.72 / 16.11 = 1.4103

So according to my calculations this should provide about 1.4 times
longer battery life compared to what you were getting earlier...
That is assuming system is mostly idle, of course.

Tony