[indiana-discuss] b111a: Power Management and nwam-issue ?

[Mark Haywood]

Mark Haywood wrote:
> Brock Pytlik wrote:
>> Mark Haywood wrote:
>>> Brock Pytlik wrote:
>>>> [snip]
>>>> Thanks, that made a huge difference. I'm now spending about 65-70% 
>>>> of time in C1 (down from 80%), but now I'm seeing my P-states 
>>>> change instead of being pegged at 2531Mhz. When I'm essentially 
>>>> idling, I'm @ 800Mhz, and popping up to higher P states periodically.
>>>
>>> That seems like a lot of time to be spending in C0. Is your system 
>>> supposed to be essentially idle? I see a lot of wakeups due to audiohd?
>>>
>> Yeah, I'm not sure why audiohd is firing that much. I was "idle" not 
>> idle. I had a few apps running, firefox, thunderbird, pidgin if I 
>> remember right, but nothing that was taxing the machine in any 
>> meaningful way. Whatever it was though apparently went away b/c I'm 
>> now at 88% in C1 and audiohd isn't showing up at all in that list. 
>> I'm not sure why it was in the first place.
>
> Hmm. event-mode might work for you now then.
>
>>>>
>>>>
>>>> One other thing I'm noticing that seems suspicious is that my 
>>>> percentage is always at 100% for one P state. It seems somewhat 
>>>> unlikely (to me at least) that it's changing P states exactly on 
>>>> every 5 second interval that powertop's using to sample. Is it 
>>>> possible that the percentage isn't doing quite what's expected?
>>>
>>> This doesn't surprise me all that much. In poll-mode the P-State 
>>> transitions are much less frequent. You probably won't see them 
>>> change often at all unless you either go from being idle to pretty 
>>> busy or from busy to idle. In event-mode you should see transitions 
>>> many times a second even on a somewhat idle system.
>>>
>> Well, I guess I expected that the percentage being reported was the 
>> percent of time (roughly) spent in that P-state during the last 
>> sampling interval (5 seconds). So, when I taxed the machine and made 
>> it jump from 800Mhz to 2531Mhz, I was surprised that during that 
>> interval, the percentage was still 100%. For example if I started 
>> taxing the machine 2.5 seconds after the last refresh, I would've 
>> expected 50% @ 800Mhz and 50% @ 2531Mhz. Perhaps I'm just 
>> misunderstanding the meaning of the number I'm seeing, but that's 
>> what this sentence from the man page would lead me to believe:
>> The tool analyzes system activity periodically and  displays a  
>> summary  of  how  long the processor is executing at each supported 
>> power state.
>
> No. I think you have it right. I just figured you might have misses 
> the 5 second window where it jumped. Maybe one of the powertop experts 
> will jump into with their opinion on this.

A known problem. See: 
http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6829404

Mark


>
> Mark
>
>>
>> Thanks,
>> Brock
>>> Mark
>>>
>>>>
>>>> Brock
>>
>
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