Mark Haywood wrote: > Li, Aubrey wrote: >> Rafael Vanoni Polanczyk wrote: >> >> >>> Aubrey Li wrote: >>> >>>> 2008/6/23 Rafael Vanoni <Rafael.Vanoni at sun.com>: >>>> >>>>> Forgot to zero cstate_info[i].events, here's the correct diff. >>>>> >>>>> >>>> Thanks for the great work, :-) >>>> This one looks good except this: >>>> >>>> -static char cpupm_treshold[] = " echo cpu-threshold 1s >> >>>> /etc/power.conf"; +static char cpupm_treshold[] = " echo >>>> cpu-threshold 5s >> /etc/power.conf"; >>>> >>>> why do we need this change? >>>> >>>> >>> Sorry I didn't comment this one before. 1s seems a bit too little, >>> don't you think? I can't remember the default, tho. >>> >>> thanks >>> rafael >>> >> Not really, intel processor can switch very quickly (in microseconds). >> That's why we are working on the subsecond p-state. So here, we should >> set this threshold as small as possible, 1s is the right value. > > I've not really been following this thread. But why is this change being > proposed and is the proposal that the change be a productized change to > Solaris? If so, please don't. I'm currently looking into making this > same change, enabling CPU power management by default and modifying the > Solaris PM framework to scan CPU devices once a second: > > 6647538 cpupm should be on by default > 6714184 x86 CPU power management could be a little more aggressive. > > Just changing cpu-threshold to 1 second (as I think you are proposing > above) isn't going to have much effect without the changes I'm planning > with the CRs above. Also, I'm currently running these changes through > our PerfPIT to see if they will have any impact on performance.
Sounds good. We just have to pay some attention to this value in the future. For instance, I have a white paper with me that suggested setting the threshold to 15s. thanks Rafael
