Summary:
While working on https://github.com/pytorch/pytorch/issues/38911, I realized that `nccl.reduce` only needs a single output tensor, while our current implementation requires a list of output tensors. This, along with a TODO I fixed in reduce_add, should have some speed up for data parallel.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39688
Differential Revision: D22034547
Pulled By: mrshenli
fbshipit-source-id: e74d54d673ebbb062474b1bb5cc93a095a3a5f6c
Adds streams and comms as optional arguments to the NCCL calls in
torch.cuda.nccl. Also exposes ncclUniqueId and ncclCommInitRank for
multi-process mode.
Moves Py_RETURN_NONE statements after the GIL is re-acquired.
This ensures that we use the same library at the C++ level and with
Python ctypes. It moves the searching for the correct library from
run-time to compile-time.
Here's the command I used to invoke autopep8 (in parallel!):
git ls-files | grep '\.py$' | xargs -n1 -P`nproc` autopep8 -i
Several rules are ignored in setup.cfg. The goal is to let autopep8
handle everything which it can handle safely, and to disable any rules
which are tricky or controversial to address. We may want to come back
and re-enable some of these rules later, but I'm trying to make this
patch as safe as possible.
Also configures flake8 to match pep8's behavior.
Also configures TravisCI to check the whole project for lint.
