I can confirm that yade is about 30% faster when profiling is disabled,
and that callgring still give similar results (except that it is a lot
more readable since you don't have to mentaly remove time spent in
mcount). No debug symbols needed either.
Bruno
Bruno Chareyre a écrit :
I just ran a profiling job, and I have a questionning result.
45% of cpu time is used for the function mcount from libc.
According to some googling :
gcc inserts calls to mcount() at the start and end of functions if
profiling (-p) is enabled.
That is good, it seems this operation will not take time if profiling
is disabled (and it takes so much time because of function calls like
iterator++ or body::byId(i)).
But then I have two questions in mind :
1. How comes valgrind/kcachegrind is not removing the time for mcount
from results? It would make sense.
2. Why could I profile for years without option -p and I could get
(apparently) consistent results?
Just asking in case somebody knows the answer already.
Bruno
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