Rafael Vanoni wrote: > 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.
I'm sure that the 15s is the whitepaper was taken from my blog. I suggested 15s in my blog because of the PM framework min scan of 15 seconds. Mark
