[tesla-dev] last five bugs listed on the page

[Rafael Vanoni]

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