Re: [Boost-users] Profiling Boost with gprof

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-11-07 05:13:52

Dave wrote:

> Hello All,
> 
> I'm trying to profile Boost Graph examples using
> gprof, but can't get any reasonable results. My system
> is Mac OS X 10.3.9 and gcc version 3.3. I compile
> programs with -pg option, but the profile does not
> seem to contain any useful information. It only shows
> "no time accumulated", or 100% for main. What am I
> doing wrong?

For the record, I never managed to get gprof produce reasonably-looking
results for STL-intensive code. It usually reports that most time is spent
in vector::push_back, or something like that. With -pg, compiler inserts
extra code in every function, and for small once, that changes running time
quite a bit.

I suggest you try valgrind (http://valgrind.org), specifically, the
"callgrind" binary. Using GUI frontend, called "KCachegrind" is also highly
recommended. Note that for BGL, you *have* to build your binary with both

  -g

and 

  -O3

options (optimization + debug symbols). -03 makes order of magnitude
difference.

- Volodya