[ltt-dev] Experiments on CPU time statistics
Michel Dagenais
michel.dagenais at polymtl.ca
Thu Nov 11 14:23:50 EST 2010
>> time statistics:
>> real 0m10.715s
>>
>> user 0m0.420s
>>
>> sys 0m6.350s
...
> Elapsed time is the total of the per-thread elapsed time I think (it's
> really been a while since I played with this code though). It would make
> sense if you have 54 threads in your system.
>
> I don't have entire confidence that the elapsed time is correct.
As a side note, while the elapsed time provided by "time" is probably
reliable, the user and system time are obtained by sampling under
asumptions which are sometimes not met. Arbitrarily large deviations
from the reality are possible. The CPU time computed from the LTTng
trace data is exact, not statistical.
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