30 Sep
2017
30 Sep
'17
1:28 p.m.
2017-09-30 17:56 GMT+02:00 Joachim Breitner
[...] I also wonder whether, when using cachegrind, the results from different machines are actually comparable. [...]
In general, they are not really comparable: cachegrind doesn't collect *actual* cache statistics, it emulates a simplified version of the caching machinery, trying to auto-detect parameters, see e.g.: http://valgrind.org/docs/manual/cg-manual.html#cg-manual.overview This doesn't mean that the numbers are useless, but they are only (good) general hints, and in rare extreme cases, they can be totally off from the real numbers. For the "real stuff", one has to use "perf", but then you can only compare numbers from the same CPU models.