RE: crash in profiling mode
Another question: The profiling mode of GHC-4.08.2 did also output (in mode +RTS -p) the time spent on garbage collection (as an additional percentage of overall running time). With the programs I tested so far under GHC-5.04.1, I never saw such an indication in a.out.prof, although for the same programs under GHC-4.08.2 considerable garbage collection times were measured.
Does this mean that:
a) the indication of garbage collection times has been dropped from profiling reports (can I obtain them in another way?),
or
b) the newer GHC is so smart that it optimised away the need for garbage collection in the particular (few) programs I tested, but otherwise the GC times will show up in profiling reports,
or
c) something else?
The inclusion of GC time in the report was wrong, since GC time wasn't included in the figure for total time, so you could get GC times of > 100%. You can get a measure of GC time vs. mutator time by adding '+RTS -sstderr' to the command line. Cheers, Simon
Hello, I want to profile a program, to find out: a) the time spent in expression evaluation per function (mutator time) b) the amount of garbage collection caused by the whole program It seems I have two options: A) compile without profiling support and run the compiled program with +RTS -sstderr B) compile with profiling support -prof -auto-all and run the compiled program with +RTS -p -sstderr In case A, I get a good measure of GC vs. mutator time, but I don't know the amount of time used by single functions, so I can't seperate between mutator time spent in the functions that really interest me and the time spent for the test frame. In case B, I can seperate mutator time spent in single functions, but I have the impression that the GC time I then get includes the GC for the profiler, and hence is useless for me, because different GC times for different algorithms might just mean that one of the algorithms requires more profiling overhead. Is this impression correct? If so, then it seems I can't obtain all the information about my program that I want, except there is an option C, of which I don't know? Any hints welcome, Janis. -- Janis Voigtlaender http://wwwtcs.inf.tu-dresden.de/~voigt/ mailto:voigt@tcs.inf.tu-dresden.de
participants (2)
-
Janis Voigtlaender -
Simon Marlow