GitLab

* [test]: add a more general test case

- also rebalance the tests a bit

* added missing arg

* balance

* better checking

* balance

* make test smaller and faster

* make ddp results cached and enable sync_bn

* clean up

* fix tests

* changelog

* blance

* fix

* addressing comments
Co-authored-by: Min Xu <min.xu@acm.org>

* [feat] experimental.nn.SyncBatchNorm: initial commit

Fast/simple re-implementation of SyncBatchNorm.

When profiling SSL Vision, I was seeing a majority of cycles spent in
SyncBatchNorm. With this change, I see a 10% to 20% speedup on the
model I was profiling.

When running benchmarks/experimental/sync_batchnorm.py on 8 x V100,
I get a 6x speedup:

<class 'torch.nn.modules.batchnorm.BatchNorm2d'>
Elapsed time is  0.08709120750427246
Elapsed time is  0.12632274627685547
Elapsed time is  0.14095258712768555
Elapsed time is  0.16529417037963867
Elapsed time is  0.1419970989227295
Elapsed time is  0.15166854858398438
Elapsed time is  0.12000870704650879
Elapsed time is  0.17534875869750977
<class 'torch.nn.modules.batchnorm.SyncBatchNorm'>
Elapsed time is  2.5087168216705322
Elapsed time is  2.497001886367798
Elapsed time is  2.5204885005950928
Elapsed time is  2.526789903640747
Elapsed time is  2.5080230236053467
Elapsed time is  2.524489641189575
Elapsed time is  2.513214588165283
Elapsed time is  2.5359973907470703
<class 'fairscale.experimental.nn.sync_batchnorm.SyncBatchNorm'>
Elapsed time is  0.4126114845275879
Elapsed time is  0.39051294326782227
Elapsed time is  0.40685415267944336
Elapsed time is  0.4159870147705078
Elapsed time is  0.42383885383605957
Elapsed time is  0.4080159664154053
Elapsed time is  0.41202712059020996
Elapsed time is  0.42400121688842773

* [feat] save memory by using bucket buffer only in backward

- this fixes bug #627
- added documentation to clarify the buffer's cost and speed/memory
  tradeoff
- added setup/teardown calls so that the buffer is only allocated
  during the backward pass, saving more memory for forward and stepping
  so that they can be used for things like activations.
- added a unit test that assert the memory is in range.

Comparing with DDP:

  1. buffer size scales with # of FSDP not model size
  2. buffer is only allocated during backward
  3. buffer is used for small tensors only to reduce overhead
  4. overlapping of compute-reduction is very different

* add PR number to changelog

* filled in with memory number on 1.9

* addressed comments

* update comments

* fix for 1.6

* add a todo
Co-authored-by: Min Xu <min.xu@acm.org>

* [fix]: let FSDP handle model with multiple forward pass and checkpoint

* try CI again

* save

* save

* fixed case with bn

* minor

* add the new file

* minor

* added test of a single case, runtime is about 50s

* enable all 8 test cases

* cleanup

* cleanup

* skip flatten case with 1.6 and 1.7

* minor
Co-authored-by: Min Xu <min.xu@acm.org>

* relax checking root condition

* formatting

* add unittest

* add unittest to ci test list

* isort for import of unittest

* format black .

* move test to list 1

* add skip no cuda

* black and isort

* FSDP: fixing training with freezing weights

- an assert is changed to catch this case correctly
- unit test added (based on Quentin's test code) for this case and
  compare DDP and FSDP

fixes: #610

* added test file to list 1

* Use better and simpler code as suggested by Myle

* testing both methods of freezing as well
Co-authored-by: Min Xu <min.xu@acm.org>

* [feat]: checkpoint and normalization

- added special handling of BN for track_running_stats and checkpointing
- we test BN/LN and checkpointing
- we test them with mixed precision

This adds a context manager that assists in making child modules with similar defaults.
Usage:
```
from fairscale.nn.misc import enable_wrap, wrap

with enable_wrap(**handleful_of_important_params):
    layer_1 = wrap(torch.nn.Linear(5, 5))
    layer_2 = wrap(torch.nn.Linear(5, 5), flatten_parameters=True) # Override parameters if you'd like

# without the context manager, creates Linear layer
layer_1 = wrap(torch.nn.Linear(5, 5))
```
If not within the FSDP context, this would be a no-op. This makes it easier to annotate layers without having to copy any changes in parameters.

* [chores]: CI py39 on GPU and more efficiency

* add test list files

* fix

* add test list files

* split benchmark run into 2 runs

* fix 1.8 version and balance benchmarks

* fix

* fix

* fix

* fix

* recording tests

* py39 install fix

* test again

* move tests

* reorg tests

* skip tests for torch 1.8 due to an upstream bug

* removed __init__.py from tests since it confuses pytest

* Revert "removed __init__.py from tests since it confuses pytest"

This reverts commit 7e156ba33dfaa5ed052031780613ec0cb57a45b0.

* don't include __init__ in file list

* notes on __init__.py and added missing ones

* fixed mypy in a test file

* balance test runtime

* better pip install

* balance more

* pip fix

* balance

* balance more, all test should finish within 20m now

* minor license update

* trying cu102

* more doc and addressed Ben's comments

* debugging

* debugging

* better capture the errors

* debugging

* fix pyenv command

* add universe repo

* update to cuda 11 for 171

* add a test file, improved the checking script