Mark.Haywood at Sun.COM wrote: > Li, Aubrey 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. >>> >>> Sorry, if I've misunderstood the intent and for not following this >>> thread more closely. >>> >>> >> >> PowerTOP will detect if cpupm is enabled in /etc/power.conf. >> If it does, then it will do nothing, otherwise it will insert "cpupm >> enable" "cpu-threshold 1s" >> into power.conf and run pmconfig. >> >> The original threshold is 1 second and Rafael want to change it >> to 5 seconds, I'm just suggesting not to do that. >> > > OK. I get to show my ignorance (again!). Why would PowerTOP modify the > system's configuration? Is this done at the request of the user? > Yes, PowerTOP will find if cpu is power managable, if so it gives a suggestion to the user to enable cpupm, and if the user wants, it will help to do it by just press one key.
I recommend you to have a try, :-) Thanks, -Aubrey
