> The frequencies is designated as P-state level. > If powertop display 100% at 2400Mhz, how could the users know it's > in P0 or P1? And When APERF/MPERF < 1 in P0, the actual speed > may < 2400 due to T-state or hardware temperature limitation. why put > it in 2400 statistics? The frequencies here are P0,P1, ... Pn. > I understand you want to show the actual speed, but doing it just in P0 > may make more sense. > > Another thing comes in my mind is, if the acutal speed 2400< P0 < 2401, > let's display 2401 as well. An increment < 1Mhz is meaningless. Let's > set > the resolution of P-state frequency to 1Mhz.
Makes sense. Will alter the code appropriately. Thanks, Vinay ----- Original Message ----- From: "Li, Aubrey" <[email protected]> Date: Thursday, August 14, 2008 6:46 pm Subject: Re: [tesla-dev] PowerTop must support Turbo mode: webrev link onopensolaris To: Vinay Devadas <Vinay.Devadas at Sun.COM> Cc: tesla-dev at opensolaris.org > Vinay Devadas wrote: > > >> P0 is not equal to turbo mode. P0 means the system is requesting to > >> the speed of the max performance. When Turbo mode is enabled, P0 give > >> the system a chance to go into turbo mode, but whether the processor > >> enter turbo mode or not is determined by the hardware. So, even if > >> APERF/MPERF may be < 1, if DTrace says we are in P0, we should let > >> PowerTOP and users know the system is requesting max performance > >> speed, not max non turbo speed. > > > > I agree with what you say above, but I am sorry I need more > > clarification on the display issue. > > > > Now say max non-turbo frequency is 2400 and P0 is 2401 as > > displayed by powertop. PowerTop does not diplay P0, P1 ... > > etc. It only displays frequencies 2000, 2400, 2401 etc. i.e. > > the display is something like, > > P-state Frequency > > 2000 > > 2400 > > 2401 > > > > Now considering your case, let us say IDA is enabled and > > Dtrace says we are in P0. CURRENTLY powertop display 100% in > > 2401. However, sampling the APERF/MPERF values, if the ratio > > <=1 we are running at 2400 MHz (*I agree in P0, but it is 2400 > > and NOT 2401*). If the ratio is larger than one, then we are > > running at some frequency higher than 2400Hz. > > > > This is precisely what I do. IDA enabled and APERF/MPERF <=1, > > I display 100% next to 2400Mhz (This means we are in P0 and > > running at 2400 Mhz). If APERF/MPERF > 1, I display AVERAGE > > frequency instead of *2401 Mhz* and the *time spent there*. > > Just because IDA is enabled will it not be incorrect to > > display 100% next to 2401 just because Dtrace probe tells we > > are in P0 as powertop does currently ? > > > > The frequencies is designated as P-state level. > If powertop display 100% at 2400Mhz, how could the users know it's > in P0 or P1? And When APERF/MPERF < 1 in P0, the actual speed > may < 2400 due to T-state or hardware temperature limitation. why put > it in 2400 statistics? The frequencies here are P0,P1, ... Pn. > I understand you want to show the actual speed, but doing it just in P0 > may make more sense. > > Another thing comes in my mind is, if the acutal speed 2400< P0 < 2401, > let's display 2401 as well. An increment < 1Mhz is meaningless. Let's > set > the resolution of P-state frequency to 1Mhz. > > Thanks, > -Aubrey > > _______________________________________________ > tesla-dev mailing list > tesla-dev at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/tesla-dev
