Reported in https://github.com/pytorch/pytorch/issues/143470, we have a dangling references in `CudaEventCache`. So we want to fix it.
1. We add a unit test to repro the issue mentioned in the issue.
2. Instead of converting variables to shared pointers as suggested in the issue, we then make the cache itself a shared pointer. So if the thread creates the cache dies before all events get recycled, the cache is still there until the last CudaEvent get deleted. (thanks for the suggestion from @kwen2501 )
Pull Request resolved: https://github.com/pytorch/pytorch/pull/144496
Approved by: https://github.com/kwen2501
We added `CudaEventCache` in https://github.com/pytorch/pytorch/pull/133727 and this is a feature which tries to reuse CudaEvent so that we don't call destroy of CudaEvent which causes hang in the past. We had a bunch of tests and testing on TorchTitan and internal workload already. So far no errors or crash are found at the moment so we decide to roll out to all OSS users. For internal workload, this PR would not affect it because of some internal gating.
Also we observed some multi-device use cases in OSS, so that we want to bring back multi-device support originally proposed in https://github.com/pytorch/pytorch/pull/122732/files.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/140975
Approved by: https://github.com/eqy, https://github.com/kwen2501
Previously:
```
[W Utils.hpp:133] Warning: Environment variable NCCL_ASYNC_ERROR_HANDLING is deprecated; use TORCH_NCCL_ASYNC_ERROR_HANDLING instead (function getCvarInt)
[W Utils.hpp:133] Warning: Environment variable NCCL_ASYNC_ERROR_HANDLING is deprecated; use TORCH_NCCL_ASYNC_ERROR_HANDLING instead (function getCvarInt)
```
With this PR, those warnings disappear. They were introduced in #114077
This change was generated with this sed script, applied with `sed -i -f /tmp/x **/*.{py,hpp,cpp,cc}` and hand inspected.
```
s/\bNCCL_BLOCKING_WAIT\b/TORCH_NCCL_BLOCKING_WAIT/g
s/\bNCCL_ENABLE_TIMING\b/TORCH_NCCL_ENABLE_TIMING/g
s/\bNCCL_DESYNC_DEBUG\b/TORCH_NCCL_DESYNC_DEBUG/g
s/\bNCCL_ASYNC_ERROR_HANDLING\b/TORCH_NCCL_ASYNC_ERROR_HANDLING/g
s/\bENABLE_NCCL_HEALTH_CHECK\b/TORCH_ENABLE_NCCL_HEALTH_CHECK/g
s/\bNCCL_USE_TENSOR_REGISTER_ALLOCATOR_HOOK\b/TORCH_NCCL_USE_TENSOR_REGISTER_ALLOCATOR_HOOK/g
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/114880
Approved by: https://github.com/kwen2501
- [c10d] (retry) Opportunistically use `ncclCommSplit` when creating new NCCL groups (#112889)
- Guard use of `split_from` with a `hasattr` check for cases when NCCL (or RCCL) lacks `ncclCommSplit`
Fixes cause of revert of original PR
Pull Request resolved: https://github.com/pytorch/pytorch/pull/114385
Approved by: https://github.com/huydhn
Currently `ncclCommInitRankConfig` is always used when creating new
communicator groups. This is wasteful as it creates non-shared pairs
of endpoint queues as well as costs time to re-establish
communication.
This change is transparent and opportunistic; when `dist.new_group` is
called, it will use the existing, healthy world process group to
select the right ranks to include in the process group.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/112889
Approved by: https://github.com/kwen2501
NCCL_ prefix should only be used for NCCL library's environment variables. We currently use a few environment variables in PyTorch with the NCCL_ prefix that are the NCCL library does not understand.
This patch renames such environment variables to use the TORCH_NCCL_ prefix instead. We still maintain the old NCCL_ variables, but throw a warning when they are used.
The following env changes have been made:
`NCCL_BLOCKING_WAIT` -> `TORCH_NCCL_BLOCKING_WAIT`
`NCCL_ENABLE_TIMING` -> `TORCH_NCCL_ENABLE_TIMING`
`NCCL_DESYNC_DEBUG` -> `TORCH_NCCL_DESYNC_DEBUG`
`NCCL_ASYNC_ERROR_HANDLING` -> `TORCH_NCCL_ASYNC_ERROR_HANDLING`
`ENABLE_NCCL_HEALTH_CHECK` -> `TORCH_ENABLE_NCCL_HEALTH_CHECK`
`NCCL_USE_TENSOR_REGISTER_ALLOCATOR_HOOK` -> `TORCH_NCCL_USE_TENSOR_REGISTER_ALLOCATOR_HOOK`
Fixes #ISSUE_NUMBER
Pull Request resolved: https://github.com/pytorch/pytorch/pull/114077
Approved by: https://github.com/fduwjj
Summary:
The getCvar* functions allow us to provide multiple environment variables for the same value. This allows us to deprecate some variables in favor of others, while still allowing users to temporarily use the old variables for some time.
Test Plan: OSS CI
Reviewed By: fduwjj, XilunWu
Differential Revision: D51225487
Fixes #ISSUE_NUMBER
Pull Request resolved: https://github.com/pytorch/pytorch/pull/113797
Approved by: https://github.com/fduwjj
If code is compiled without `glog`, there are no way to control log levels other than explicitly calling `c10::initLogging()`
Test plan: Run `TORCH_CPP_LOG_LEVEL=0 ./bin/ProcessGroupNCCLTest` and observe extra log messages
Pull Request resolved: https://github.com/pytorch/pytorch/pull/112809
Approved by: https://github.com/fduwjj
Avoid changing default for other backends as CPU backend (GLOO) may need
longer timeouts.
Motivated by trying to save cluster time when encountering collective
hangs. Generally collectives should time out within seconds and 30
minutes (or 10 minutes) should provide ample headroom for edge cases.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110947
Approved by: https://github.com/xw285cornell, https://github.com/fduwjj
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/88330
### Implementation
Move backend-specific (NCCL, Gloo, etc) collective implementations to corresponding `Backend` class. Update ProcessGroup to support multiple backends and use dispatcher to calls backends based on tensor device type.
### Changes
#### c++ changes (ProcessGroup files, `Ops.cpp`, `init.cpp`)
- Update pybind definitions for new process group base class and new backend class
- Update pybinded backend class with collective definitions to keep BC with Python PG instances (e.g. `dist.ProcessGroupGloo`, `dist.ProcessGroupNCCL`) which are used in tests
- Switch `ProcessGroupGloo`, `ProcessGroupNCCL`, `ProcessGroupMPI`, `ProcessGroupUCC` to derive from the `Backend` class.
- Update CPU/CUDA `Ops.cpp` and `OpsImpl.cpp` to perform this dispatching by querying the backend using the device type
- Update internal dispatched implementation of `barrier` to use a tensor which allows operation to be dispatched.
- Update `allgather` collective to use `TensorList`. For some reason it was using the default implementation of `allgather` rather than dispatching it correctly. I still don't understand why and had originally filed an issue in 85122.
#### python changes (`distributed_c10d.py`, test files)
- Add BackendConfig class to specify the default configurations of backends and `get_backend_config()` API
- `get_backend()` deprecation warning
- `init_process_group` how returns a generic `ProcessGroup` object, it contains a list of backends (the ones stated above) which it will dispatch operations to.
- `new_group` updated to return the same as above
- Update `test_c10d_gloo.py`, Update `DistributedDataParallelTest` to use `init_process_group`, Update `ReducerTest`, update `test_broadcast_coalesced_gloo` to move from PG instance and gloo options
- Update `test_c10d_nccl.py`, Update `DistributedDataParallelTest` to use `init_process_group`
- Specific tests updated: `test_Backend_enum_class`
### Changes missing
- lazy initialization of backends
- support parsing of BackendConfig
### open questions
- Pure Python PG extensions (https://github.com/pytorch/pytorch/pull/66338)
# Example
This is a basic script (using 2 backends within a process group)
```python
# python -m torch.distributed.run --nnodes=1 --nproc_per_node=2 basic_scenario.py
import torch.distributed as dist
import torch
import os
if __name__ == "__main__":
rank = os.environ.get("RANK")
# initialize with both gloo and nccl
dist.init_process_group()
# with gloo
dist.all_reduce(torch.tensor([1.0]))
print(f"Rank {rank} finished")
# with nccl
dist.all_reduce(torch.tensor([1.0], device=f"cuda:{rank}"))
```
Test Plan: Imported from OSS
Differential Revision: D42069829
Pulled By: H-Huang
Pull Request resolved: https://github.com/pytorch/pytorch/pull/90997
Approved by: https://github.com/awgu, https://github.com/fduwjj
Headers under torch/csrc/distributed may be referened with relative path, e.g., "<c10d/...>". However, relative path cannot be gracefully handled by Meta internal build when the NCCL PG is hipified to support AMD/RCCL because the "hipified" header files are generated in other directories. Moreover, using absolute path for header inclusion is the state-of-the-art in most components in Pytorch. Thus, this patch refactors all header paths in torch/csrc/distributed to be absolute.
See D39835774 for more details about Meta internal complication.
**How to test**: commit 9e5d199 removes -I./torch/csrc/distributed in compile options. Thus use it to verify we don't miss any relative path use of torch/csrc/distributed headers.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85780
Approved by: https://github.com/kumpera, https://github.com/huydhn
Headers under torch/csrc/distributed may be referened with relative path, e.g., "<c10d/...>". However, relative path cannot be gracefully handled by Meta internal build when the NCCL PG is hipified to support AMD/RCCL because the "hipified" header files are generated in other directories. Moreover, using absolute path for header inclusion is the state-of-the-art in most components in Pytorch. Thus, this patch refactors all header paths in torch/csrc/distributed to be absolute.
See D39835774 for more details about Meta internal complication.
**How to test**: commit 9e5d199 removes -I./torch/csrc/distributed in compile options. Thus use it to verify we don't miss any relative path use of torch/csrc/distributed headers.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85780
Approved by: https://github.com/kumpera
### Changes
- Move ProcessGroup::Work into its own class and update all the references to it / header includes.
#### Motivation
In the future PRs we will repurpose ProcessGroup to instead contain a list of Backends (ProcessGroupNCCL/Gloo/UCC) and perform dispatching to them based on tensor type. This change is prevent a circular dependency with ProcessGroup depending on Backend and Backend depending on ProcessGroup::Work.
Differential Revision: [D38839212](https://our.internmc.facebook.com/intern/diff/D38839212)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/83680
Approved by: https://github.com/kwen2501
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67668
This adds an env var to enable NCCL health check, which when left unspecified, results in the check not being run. Unit tests that need to test this functionality have the env variable set. Please see internal diff for more details.
Test Plan: CI
Reviewed By: yuguo68, mrshenli
Differential Revision: D32089763
fbshipit-source-id: dff5664a5e607f711515cd1042089ca769914fbb
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66744
Modified loops in files under fbsource/fbcode/caffe2/ from the format
`for(TYPE var=x0;var<x_max;x++)`
to the format
`for(const auto var: irange(xmax))`
This was achieved by running r-barnes's loop upgrader script (D28874212) with some modification to exclude all files under /torch/jit and a number of reversions or unused variable suppression warnings added by hand.
Test Plan: Sandcastle
Reviewed By: ngimel
Differential Revision: D31705358
fbshipit-source-id: d6ea350cbaa8f452fc78f238160e5374be637a48
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66234
Modified loops in files under fbsource/fbcode/caffe2/ from the format
`for(TYPE var=x0;var<x_max;x++)`
to the format
`for(const auto var: irange(xmax))`
This was achieved by running r-barnes's loop upgrader script (D28874212) with some modification to exclude all files under /torch/jit and a number of reversions or unused variable suppression warnings added by hand.
bypass_size_limit
allow-large-files
Test Plan: Sandcastle
Reviewed By: ngimel
Differential Revision: D30652629
fbshipit-source-id: 0ae6c4bbbb554bad42e372792a6430e1acf15e3e
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66393
Third try!
Fixes:
- test_nccl_timeout can be flaky because of 1s timeout, bump up the timeout to resolve the flakiness. But in general we should not have been relying on time.sleep for this test, filed https://github.com/pytorch/pytorch/issues/66354 to track that.
- ciflow/all did not actually run tests due to a bug causing multigpu tests to not be run. This has since been fixed.
ghstack-source-id: 140560113
Test Plan: CI
Reviewed By: mrshenli
Differential Revision: D31534735
fbshipit-source-id: 8b7e0f4fed3972b7a77cbcda28876c9eefb0c7e2
