New submission from Dimitar Tasev:
Hello, I have noticed a significant performance regression when allocating a
large shared array in Python 3.x versus Python 2.7. The affected module seems
to be `multiprocessing`.
The function I used for benchmarking:
from timeit import timeit
timeit
Dimitar Tasev added the comment:
If I understand correctly, there is no way to force the old behaviour in Python
3.5, i.e. to use an anonymous memory mapping in multiprocessing.heap.Arena so
that the memory can be shared between the processes instead of writing to a
shared file?
The data
Dimitar Tasev added the comment:
I have looked into your advice of changing multiprocessing.heap.Arena.__init__,
I have removed the code that allocated the file and reverted to the old
behaviour.
I have done some brief runs and it seems to bring back the old behaviour which
is allocating the
Dimitar Tasev added the comment:
Thank you, that is indeed the solution I ended up with, along with a large
explanation of why it was necessary.
Do you think that it's worth updating the `multiprocessing` documentation to
make users aware of that beha
