Statistical theory behind OProfile
Donald Johnson <[email protected]>
| Newsgroups | gmane.linux.oprofile |
|---|---|
| Message-ID | <CAML0rej+C0R27HNHOey3t7TDrWc+BZizhboxFvT3in2mh2qF0w@mail.gmail.com> |
Hello, I wanted to use oprofile and apply some statistical work while profiling some the programs I work on. I'm wondering what the statistical theory and probably also computer science theory behind the program is. There are two sources I've found on the subject that I can currently access. "Yet another oprofile tutorial"[1] goes through statistical theory behind it, but I can't seem to cross-reference the entire source with anything and it does not have sources on its own. It seems solid, however, but it's in a weird place where since there's nothing to verify all of it with that I am skeptical. "A Randomized Sampling Clock for CPU Utilization Estimation and Code Profiling"[2] is a paper on the subject that I would like to find more material like it on, but I am terrible at traversing academia and the like. It goes through the general process that statistical profiling is and what distributions it comes from, but more interestingly it specifies the bias that can arise from timers that do not have sufficient randomness attached to them. However, the article is 12 years old, so the implementation details that produce bias may not apply. In short, I wondering what sort of behind-the-scenes process oprofile is statistically. It just returns samples. I'd like to know the distribution it would come from (which seems to be the Poisson distribution based on my sources) so I may gather some intuition from the output. I also want to know if OProfile does its sampling in a manner that may introduce bias. The environment I am working on is an armv5 board, which means I have to use release 0.9.9 for software interrupts. Any insight is appreciated. Thank you, Donald Johnson [1] - http://ssvb.github.io/2011/08/23/yet-another-oprofile-tutorial.html [2] - http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.50.3208&rep=rep1&type=pdf ------------------------------------------------------------------------------