ziming-zh
commented
2 months ago @namhyung Thank you for the feedback! I've made the requested changes:
- [x] Updated the commit message to include a "report:" prefix.
- [x] Removed unrelated changes from the commit.
- [x] Added example output of the new user-facing changes, including the standard deviation of the
Fibonacciandabcexample in the report. - [x] Updated the test suite to verify the behavior of the new changes.
- [x] Updated the documentation for uftrace-report and uftrace-tui to include information about the new fields.
Please review the changes and let me know if there are any further suggestions or modifications needed.
namhyung
Hello @namhyung,
I've tried to incorporate STDDEV calculation in the report output. It can now be displayed from
report -f allcommand. In order to minimize the calculation overhead, I employ efficient running STDDEV calculation following the method according this post:stdev = sqrt((sum_x2 / n) - (mean * mean)), wheremean = sum_x / n.This method involves sqrt calculation, which is the main calculation overhead, the sqrt result should be rounded to uint_64 (ns) in consistency with the format of other statistics. I've tried optimization targeted on (int) -> (int) sqrt calculation. However, it turns out that the fastest way is still using the std C math library, and cast the result to an int value. Relevant discussion could be found in this post
result = (int) sqrt(i)(Note: In that case, the compilation tag -lm should be added to the makefile)
I've run on the tests and see that the pass/fail condition would be the same before / after the modification. I've also run defect detection tool Infer to guarantee that no more new defects have been introduced.
Subsequently, I've run the uftrace w/ & w/o STDDEV calculation on the same
mnist.pycode (adopted frompytorch/example). Despite the two new columns added to the report, there seems no significant difference of the avg/min/max execution time in other columns, which means that the added STDDEV feature would not evidently interfere the original tracer functionality.I've also run Facebook's Infer tool to check for potential defection in the current code base. I've made three adjustment to the file handling (no close for open) and memory deallocation (no free after xalloc) in
utils/dwarfs.c. I've attached the complete infer report in bugs.txt and report.csv, please see if you need help to check and correct the remaining of them.Finally, I must say this is such a good projects with very well-done documentation and superb functionality. Thank you for your effort! Please let me know for further revision of this PR.