Rafael Vanoni wrote:
> Eric Saxe wrote:
>> [snip]
>>>   
>> I guess there's two ways of looking at this:
>> A) PowerTOP is reporting on the events that are causing CPUs to wake up.
>> B) PowerTOP is reporting on the events that are (or can) cause CPUs to 
>> wake up.
>>
>> Perhaps one could be the default behavior, and the other could be 
>> enabled with an option. My impression is that A is the default that 
>> folks would expect, but I think B is useful. I think B is the way the 
>> tool works now.
>>
>> To get A, I think PowerTOP needs "D" code that is able to correlate 
>> firing of the cyclic-fire probe with a firing of the 
>> idle-state-transition, and reports only the cyclic-firing that 
>> actually caused the CPU to wake up.
> 
> Ok, I modified the D script that events.c uses (cyclic-wakeups.d).
> I believe it does what Eric is suggesting, but not with the desired 
> output (output.txt). It only reports cyclic events that generate an idle 
> to active state transition. I'm not sure that's what we want.
> 
> I ran some tests and the timestamp for the firing of unix`cbe_hres_tick, 
> genunix`clock and genunix`cyclic_timer are extremely close to each 
> other. I'm running some tests that set a granularity for observing 
> activity. It fixes our current problem and could eventually be used as a 
> feature.

Ok, that turned out to be a bad idea ;)

I changed the dtrace script on events.c (attached) so that clock 
activity would only take unix`cbe_hres_tick into account, ignoring 
genunix`clock and genunix`cyclic_timer. I'm assuming that unix`cbe will 
always fire first - not sure if that's correct.

However, the aggregate cpu wakeups still don't add up correctly. I'm 
looking into that now.

Rafael


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