[squeak-dev] Re: How to profile a server image?

Andreas Raab andreas.raab at gmx.de
Thu Mar 5 07:31:58 UTC 2009


Thanks! I've updated

   http://bugs.squeak.org/view.php?id=7301

with your version.

Cheers,
   - Andreas

Juan Vuletich wrote:
> Juan Vuletich wrote:
>> ...
>>
>> - I removed the SpyPriority classVar. If spying on all processes, I 
>> use a really high priority. If spying on single process, I use a 
>> slightly higher priority than his (using a a really high priority 
>> would not hurt, though). This is just a matter of taste.
>> ...
> Thinking better about it, now I believe using any priority but the 
> maximum possible is wrong. The new code uses Processor preemptedProcess 
> to know which process we are tallying. But #preemptedProcess will never 
> answer a process with higher priority than the current. This makes 
> sense, otherwise it would be called #previousRunningProcess or something 
> like that.
> 
> Now, let's suppose that the tally process wakes up after a higher 
> priority process ends or yields, after using some cpu. #preemptedProcess 
> will answer another process, one with lower priority, and its time slice 
> will be added to it. So it will seem as if the higher priority process 
> never ran and the lower priority one used all the time. This is an 
> incorrect answer.
> 
> So this is a real bug. The attached version fixes this, and a couple of 
> other bugs, especially when tallying a single process. So, please 
> disregard the one I sent earlier. I also added acouple of examples in 
> the comment in class methods.
> 
> Andreas, please take a look.
> 
> Thanks,
> Juan Vuletich
> 
> 
> ------------------------------------------------------------------------
> 
> 




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