yade-dev team mailing list archive

["Janek Kozicki (yade)" <jkozicki-yade@xxxxxxxxx>]

> Another note: I just realized that the compilation benchmarks might
> have not been fair, because I think that I added few more
> registrations (like Vector2c, or sth. like that) while doing pybind
> migration. I will compare again without these extra registrations.

OK, I have compared with the exact same registrations. And it seems
that pybind has many advantages, but not the one that it is compiling
faster. See:

pybind without debug info; call `ccache --clear` between every invocation.
-O3 -j 1                           -O3 -j 10
    wall clock time: 2:41.14           wall clock time: 0:40.67
    wall clock time: 2:46.56           wall clock time: 0:41.28
    wall clock time: 2:47.42           wall clock time: 0:42.54
    wall clock time: 2:43.79           wall clock time: 0:44.70
                                   
-O1 -j 1                           -O1 -j 10
    wall clock time: 2:09.88           wall clock time: 0:35.00
    wall clock time: 2:10.78           wall clock time: 0:33.46
    wall clock time: 2:08.19           wall clock time: 0:32.62
    wall clock time: 2:10.10           wall clock time: 0:32.73

================================================================================
boost::python without debug info; call `ccache --clear` between every invocation.
-O3 -j 1                           -O3 -j 10
    wall clock time: 2:16.83           wall clock time: 0:33.88
    wall clock time: 2:15.96           wall clock time: 0:32.84
    wall clock time: 2:16.00           wall clock time: 0:34.85
    wall clock time: 2:16.52           wall clock time: 0:32.32
                                   
-O1 -j 1                           -O1 -j 10
    wall clock time: 2:01.48           wall clock time: 0:28.56
    wall clock time: 2:00.70           wall clock time: 0:29.15
    wall clock time: 2:01.29           wall clock time: 0:28.05
    wall clock time: 2:00.56           wall clock time: 0:28.35

The main pybind disadvantage is unstable API. I don't like writing
extra code to support older linux distributions.


Also I think that if while copying minieigen into yade we did some
extra rebalancing between the .cpp files, so that in each file there's
about the same amount of registrations performed, then we could
reduce (parallel) compilation time to maybe 25 or 20 seconds.


If you wanted to compile and try yourself, the comparison was between
branches master and tryPybind. To see how to compile see .gitlab-ci.yml,
I'm sorry that it's a bit messy. I was never good at using build
systems ;) I just wanted parallel build quickly. That's why I wrote
such strange makefile.

best regards
Janek


 
> Another comparison note:
> 
> 8. boost::python is much more picky about the order of registered
>    functions, and sometimes does not work if the order is "wrong".
>    pybind always resolves the function overloads correctly.

-- 
--
Janek Kozicki, PhD. DSc. Arch. Assoc. Prof.
Gdańsk University of Technology
Faculty of Applied Physics and Mathematics
Department of Theoretical Physics and Quantum Information
--
http://yade-dem.org/
http://pg.edu.pl/jkozicki (click English flag on top right)