This repository holds PyTorch bindings maintained by Intel for the Intel® oneAPI Collective Communications Library (oneCCL).
PyTorch is an open-source machine learning framework.
Intel® oneCCL (collective commnications library) is a library for efficient distributed deep learning training implementing such collectives like allreduce, allgather, alltoall. For more information on oneCCL, please refer to the oneCCL documentation.
torch-ccl module implements PyTorch C10D ProcessGroup API and can be dynamically loaded as external ProcessGroup and only works on Linux platform now.
We recommend Anaconda as Python package management system. The following is the corresponding branchs (tags) of torch-ccl and supported Pytorch.
torch |
torch-ccl |
|---|---|
master |
master |
| v1.6.0 | ccl_torch1.6 |
| v1.5-rc3 | 2021.1-beta09 |
The usage details can be found in the README of corresponding branch. The following part is about the usage of master. if you want to use other version of torch-ccl please checkout to that branch(tag).
Python 3.6 or later and a C++14 compiler
PyTorch master branch.
To install torch-ccl:
-
Install PyTorch from source code.
-
Install the
torch-ccl.
git clone https://github.com/intel/torch-ccl.git && cd torch-ccl
git submodule sync
git submodule update --init --recursive
python setup.py install- oneCCL is used as third party repo of torch-ccl but you need to source the oneCCL environment before runing.
$ torch_ccl_path=$(python -c "import torch; import torch_ccl; import os; print(os.path.abspath(os.path.dirname(torch_ccl.__file__)))")
$ source $torch_ccl_path/ccl/env/setvars.sh
example.py
import torch.nn.parallel
import torch.distributed as dist
import torch_ccl
...
os.environ['MASTER_ADDR'] = '127.0.0.1'
os.environ['MASTER_PORT'] = '29500'
os.environ['RANK'] = os.environ.get('PMI_RANK', -1)
os.environ['WORLD_SIZE'] = os.environ.get('PMI_SIZE', -1)
backend = 'ccl'
dist.init_process_group(backend, ...)
my_rank = dist.get_rank()
my_size = dist.get_world_size()
print("my rank = %d my size = %d" % (my_rank, my_size))
...
model = torch.nn.parallel.DistributedDataParallel(model, ...)
...$ torch_ccl_path=$(python -c "import torch; import torch_ccl; import os; print(os.path.abspath(os.path.dirname(torch_ccl.__file__)))")
$ source $torch_ccl_path/ccl/env/setvars.sh
$ mpirun -n <N> -ppn <PPN> -f <hostfile> python example.py
For debugging performance of communication primitives PyTorch's Autograd profiler can be used to inspect time spent inside oneCCL calls.
Example:
profiling.py
import torch.nn.parallel
import torch.distributed as dist
import torch_ccl
backend = 'ccl'
dist.init_process_group(backend, ...)
my_rank = dist.get_rank()
my_size = dist.get_world_size()
print("my rank = %d my size = %d" % (my_rank, my_size))
x = torch.ones([2, 2])
y = torch.ones([4, 4])
with torch.autograd.profiler.profile(record_shapes=True) as prof:
for _ in range(10):
dist.all_reduce(x)
dist.all_reduce(y)
dist.barrier()
print(prof.key_averages(group_by_input_shape=True).table(sort_by="self_cpu_time_total"))$ torch_ccl_path=$(python -c "import torch; import torch_ccl; import os; print(os.path.abspath(os.path.dirname(torch_ccl.__file__)))")
$ source $torch_ccl_path/ccl/env/setvars.sh
$ mpirun -n 2 -l python profiling.py
[0] rank = 0, size = 2
[0] ------------------------------ --------------- --------------- --------------- --------------- --------------- --------------- ---------------
[0] Name Self CPU total % Self CPU total CPU total % CPU total CPU time avg Number of Calls Input Shapes
[0] ------------------------------ --------------- --------------- --------------- --------------- --------------- --------------- ---------------
[0] pg::allreduce 37.70% 61.935us 37.70% 61.935us 6.194us 10 [[2, 2]]
[0] pg::allreduce 23.40% 38.438us 23.40% 38.438us 3.844us 10 [[4, 4]]
[0] pg::wait::allreduce::sz:16 19.64% 32.258us 19.64% 32.258us 3.226us 10 []
[0] pg::wait::allreduce::sz:4 19.26% 31.634us 19.26% 31.634us 3.163us 10 []
[0] ------------------------------ --------------- --------------- --------------- --------------- --------------- --------------- ---------------
[0] Self CPU time total: 164.265us
[0]
[1] rank = 1, size = 2
[1] ------------------------------ --------------- --------------- --------------- --------------- --------------- --------------- ---------------
[1] Name Self CPU total % Self CPU total CPU total % CPU total CPU time avg Number of Calls Input Shapes
[1] ------------------------------ --------------- --------------- --------------- --------------- --------------- --------------- ---------------
[1] pg::allreduce 50.27% 62.730us 50.27% 62.730us 6.273us 10 [[2, 2]]
[1] pg::allreduce 28.96% 36.133us 28.96% 36.133us 3.613us 10 [[4, 4]]
[1] pg::wait::allreduce::sz:4 13.83% 17.254us 13.83% 17.254us 1.725us 10 []
[1] pg::wait::allreduce::sz:16 6.95% 8.672us 6.95% 8.672us 0.867us 10 []
[1] ------------------------------ --------------- --------------- --------------- --------------- --------------- --------------- ---------------
[1] Self CPU time total: 124.789us
[1]