This PR contains multiple fixes for issue https://github.com/pytorch/pytorch/issues/135279:
## First part:
Moves the GPU guard (`cudaSetDevice`) before the `currentStreamCaptureStatusMayInitCtx` call.
As its name suggests, it May Init Ctx.
## Second part:
Even with the above fix, additional contexts are still observed during Work object destruction, e.g.
```
work = dist.all_reduce(tensor, async_op=True)
time.sleep(5) <-- no additional context yet
del work <-- additional context shows up
```
### Debug process
Chasing it down to destruction of a `Future` object -- a member variable of `Work`.
Then further down to the following member of `Future`:
```
std::vector<c10::Event> events_;
```
When the `events_` are destroyed, we hit the road down to:
1f3a793790/c10/cuda/impl/CUDAGuardImpl.h (L106-L121)
When there is no "preset" CUDA context (**which is the case for python garbage collector**), line 112: `c10::cuda::GetDevice(&orig_device)` will set `orig_device` to 0. Then, at line 120, `c10::cuda::SetDevice(orig_device)` will "officially" set the context to device 0 --
**that's where rank 1, 2, ... can create extra context on device 0!**
### Solution
This PR adds an explicit destructor to `Future`. In this destructor, destroy each event with a device guard.
## Test
Added test_extra_cuda_context, implemented via
- `pynvml` (if available), or
- memory consumption check.
`python test/distributed/test_c10d_nccl.py -k test_extra_cuda_context`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/135273
Approved by: https://github.com/fduwjj, https://github.com/wconstab, https://github.com/eqy
ghstack dependencies: #137161
This PR contains multiple fixes for issue https://github.com/pytorch/pytorch/issues/135279:
## First part:
Moves the GPU guard (`cudaSetDevice`) before the `currentStreamCaptureStatusMayInitCtx` call.
As its name suggests, it May Init Ctx.
## Second part:
Even with the above fix, additional contexts are still observed during Work object destruction, e.g.
```
work = dist.all_reduce(tensor, async_op=True)
time.sleep(5) <-- no additional context yet
del work <-- additional context shows up
```
### Debug process
Chasing it down to destruction of a `Future` object -- a member variable of `Work`.
Then further down to the following member of `Future`:
```
std::vector<c10::Event> events_;
```
When the `events_` are destroyed, we hit the road down to:
1f3a793790/c10/cuda/impl/CUDAGuardImpl.h (L106-L121)
When there is no "preset" CUDA context (**which is the case for python garbage collector**), line 112: `c10::cuda::GetDevice(&orig_device)` will set `orig_device` to 0. Then, at line 120, `c10::cuda::SetDevice(orig_device)` will "officially" set the context to device 0 --
**that's where rank 1, 2, ... can create extra context on device 0!**
### Solution
This PR adds an explicit destructor to `Future`. In this destructor, destroy each event with a device guard.
## Test
Added test_extra_cuda_context, implemented via
- `pynvml` (if available), or
- memory consumption check.
`python test/distributed/test_c10d_nccl.py -k test_extra_cuda_context`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/135273
Approved by: https://github.com/fduwjj, https://github.com/wconstab, https://github.com/eqy
skip_if_rocm is used only in multiprocess case (when UT test class is a child of MultiProcessTestCase). Each individual process can exit with a skip code. If used for single process UT, it will cause the UT to fail as the process returns a non-zero exit code. Use skipIfRocm in single process UTs.
To avoid the above confusion, this PR renamed skip_if_rocm to skip_if_rocm_multiprocess.
Fixes #ISSUE_NUMBER
Pull Request resolved: https://github.com/pytorch/pytorch/pull/136161
Approved by: https://github.com/jithunnair-amd, https://github.com/kwen2501, https://github.com/fegin
This PR creates these `GroupedSchedulerNode`s:
- One for each all-gather code block (cast + copy-in + all-gather)
- One for each all-gather-wait code block (all-gather-wait + copy-out)
- One for each reduce-scatter code block (copy-in + reduce-scatter)
- One for each reduce-scatter-wait code block (reduce-scatter-wait)
This serves two goals:
- Prevent outside ops from being fused into these op groups, in order to have more predicable memory usage.
- Make it easier to specify the dependency e.g. from `i+1` all-gather group node to the `i` all-gather-wait group node, to enforce FSDP2 comm ordering (i.e. "serialization of comms").
The actual "reorder-for-FSDP-compute-comm-overlap" PR will come next.
Test commands:
- `pytest -rA test/distributed/test_compute_comm_reordering.py::TestComputeCommReorderingMultiProc`
- `pytest -rA test/distributed/_composable/fsdp/test_fully_shard_compile.py::TestFullyShardCompile::test_transformer_backend_inductor`
- `pytest -rA test/distributed/_composable/fsdp/test_fully_shard_compile.py::TestFullyShardCompile::test_nested_fully_shard_backend_inductor`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/131510
Approved by: https://github.com/yifuwang
Summary: `test/distributed/_composable/test_replicate_with_compiler.py` exercises inductor. This change introduces a version of MultiProcessTestCase that derives from the inductor TestCase class to make sure we always get a clean cache dir.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/129494
Approved by: https://github.com/eellison
**Summary**
This PR switches the default TCPStore server backend to a new implementation that utilizes [`libuv`](https://github.com/libuv/libuv) for significantly lower initialization time and better scalability:
<img width="714" alt="image" src="https://github.com/pytorch/pytorch/assets/12968408/18503011-da5d-4104-8ba9-abc456438b02">
We hope this improvement would benefit users from a much shorter startup time in large-scale jobs. Eventually, we hope to fully replace the old TCPStore backend implementation with the libuv one.
**What it changes**
This PR changes the underlying TCPStore server backend to `libuv` if users don't explicitly specify to use the old TCPStore server. This change is not supposed to cause any user notice except significant faster TCPStore startup for large-scale jobs.
One thing to note is, we do not support the initialization approach where user passes in a socket for libuv backend. We plan to support it as a next step but we choose to disable it before fully testing. If you are initializing TCPStore in this approach, you can see the next section to remain using the old TCPStore server.
**Fallback/Remain using the old TCPStore server**
For users who want to stay with the old TCPStore backend, there're 3 ways:
1. If user is directly instantiating TCPStore object, user can pass in argument `use_libuv=False` to use the old TCPStore server backend e.g. `store = torch.distributed.TCPStore(..., use_libuv=False)`.
2. Or, specify the TCPStore backend option in `init_method` when calling default ProcessGroup init, e.g. `torch.distributed.init_process_group(..., init_method="{YOUR_RENDEZVOUS_METHOD}://{YOUR_HOSTNAME}:{YOUR_PORT}?use_libuv=0")`
3. Or, user can set environment variable `USE_LIBUV` to `"0"` when launching.
These 3 approach are in order of precedence. That being said, if user specifies `use_libuv=0` in `init_method` and also sets environment var `USE_LIBUV="1"`, the former will take effect and the TCPStore backend instantiated will be the old one instead of the one using libuv.
**Operating Systems Compatibility**
From the CI signals, we believe the new implementation has the same behavior as the old TCPStore server on all supported platforms. If you notice any behavior discrepancy, please file an issue with `oncall: distributed` label.
**Test Plan**
`pytest test/distributed/test_store.py`
<img width="2548" alt="image" src="https://github.com/pytorch/pytorch/assets/12968408/dc0aebeb-6d5a-4daa-b98c-e56bd39aa588">
note: `TestMultiThreadedWait::test_wait` is a broken test that has been there for some time.
`test/distributed/elastic/utils/distributed_test.py`
<img width="2558" alt="image" src="https://github.com/pytorch/pytorch/assets/12968408/a6a3266d-b798-41c4-94d2-152056a034f6">
**TODO**
1. Update the doc at
- https://pytorch.org/docs/stable/distributed.html#distributed-key-value-store
- https://pytorch.org/docs/stable/distributed.html#tcp-initialization
2. Make torch elastic rendezvous to use libuv TCPStore as well. See `torch/distributed/elastic/rendezvous/c10d_rendezvous_backend.py` cc @mrshenli @pritamdamania87 @zhaojuanmao @satgera @gqchen @aazzolini @osalpekar @jiayisuse @H-Huang @kwen2501 @awgu @penguinwu @fegin @wanchaol @fduwjj @wz337 @tianyu-l @wconstab @yf225 @chauhang @d4l3k @kurman
3. Test if libuv backend is okay with initialization with socket. Change `LibUvTCPStoreTest::test_take_over_listen_socket`.
**Test Plan**
`pytest test/distributed/test_store.py`
<img width="2548" alt="image" src="https://github.com/pytorch/pytorch/assets/12968408/dc0aebeb-6d5a-4daa-b98c-e56bd39aa588">
note: `TestMultiThreadedWait::test_wait` is a broken test that has been there for some time.
`test/distributed/elastic/utils/distributed_test.py`
<img width="2558" alt="image" src="https://github.com/pytorch/pytorch/assets/12968408/a6a3266d-b798-41c4-94d2-152056a034f6">
Differential Revision: [D58259591](https://our.internmc.facebook.com/intern/diff/D58259591)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/127957
Approved by: https://github.com/kurman
ghstack dependencies: #127956
This CI showcases FSDP2 works with `torch.compile` root model, since FSDP1 can do the same
compiling root Transformer without AC: `pytest test/distributed/_composable/fsdp/test_fully_shard_training.py -k test_train_parity_multi_group`
compiling root Transformer with AC: `pytest test/distributed/_composable/fsdp/test_fully_shard_training.py -k test_train_parity_with_activation_checkpointing`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/127832
Approved by: https://github.com/awgu
## Problem this PR resolves
Today, most of distributed tests are arranged like this:
```
def test_allreduce(self):
pg = self._create_process_group_nccl(store, self.opts())
pg.allreduce(tensor)
...
```
Thus, we are paying PG creation time **per test**. That's bad. But why were we doing that? Is there a constraint?
If we look deeper, we would find that most of our test cases inherit from `torch.testing._internal.common_distributed.MultiProcessTestCase`. From the name, nothing seems wrong, and probably fits distributed well. But a "problem" exists in its `setUp()` and `tearDown()` methods, which basically do the following:
```
def setUp(self):
self._spawn_processes()
def tearDown(self):
for p in self.processes:
p.terminate()
```
Since `setUp` and `tearDown` are "**test-scope fixtures"**, meaning, they are called per test, each test will have brand new processes. Of course we'd have to recreate ProcessGroup every time.
## How we are fixing it
First, obviously, we need to put a PG's lifetime into a longer scope. Python `unittest` provides such a helper, called **"class-scope fixtures."** It is embodied by a `setUpClass` method and a `tearDownClass` method (note the name difference), which are called only once for all tests in the same test class. Therefore, we would do:
```
@classmethod
def setUpClass(self):
dist.init_process_group(...)
@classmethod
def tearDownClass(self):
dist.destroy_process_group()
```
**In this PR, we create a new test template for distributed: `MultiProcContinousTest`, to hold this class-scope fixture.**
Second, we'd need to avoid per-test process spawn and terminate. That's easy, we can either:
1. launch the whole test file with `torchrun --nproc-per-node=...` or
2. use `mp.spawn()` under `if __name__ == "__main__":`.
Point is, launch the processes only once.
## Result
We moved the "positive tests" from test_c10d_nccl.py to test_c10d_ops_nccl.py.
Before this PR:
```
$ python test_c10d_nccl.py -k ProcessGroupNCCLTest
Ran 24 tests in 174.457s
```
After this PR:
```
$ torchrun --nproc-per-node 2 test_c10d_ops_nccl.py
or
$ python test_c10d_ops_nccl.py
Ran 24 tests in 16.247s
```
10X speedup.
## Limitation
For tests intended to test destroy or abort of PGs, we'd need to go back to the old style. So it would make sense to divide our tests into two classes: one for positive tests where we would reuse the PGs, and the other one for abort/destroy and negative tests like watchdog timeout.
## Next step
Migrate the tests of distributed that would fit with this test style!
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125648
Approved by: https://github.com/wconstab
Update ruff to 0.4.1 .
This version fixes a lot false negatives/false positives, is 20-40% faster, and has various other bug fixes.
Below is a before and after table showing the execution time of ruff lint and ruff format in milliseconds courtesy of https://astral.sh/blog/ruff-v0.4.0
| Repository | Linter (v0.3) | Linter (v0.4) | Formatter (v0.3) | Formatter (v0.4) |
|----------------------------------------------------|---------------|---------------|------------------|------------------|
| [pytorch/pytorch](https://github.com/pytorch/pytorch) | 328.7 | 251.8 | 351.1 | 274.9 |
Pull Request resolved: https://github.com/pytorch/pytorch/pull/124549
Approved by: https://github.com/ezyang
## Summary
After this PR, the functional collective Python APIs will stop honoring `TORCH_DISABLE_NATIVE_FUNCOL` and only use native funcol ops. Specifically, this PR:
- Removed `use_native_funcol()`.
- Removed the code path in the Python APIs when `use_native_funcol()` is `False`.
- Changed the CI tests that runs on both native funcol and legacy funcol through the Python API to only run with native funcol.
## Test Changes
`test_functional_api.py`
- Removed the tests where only one of output_split_sizes or input_split_sizes is specified. This behavior is unreliable has been removed from the native funcol.
- Removed `TestWaitiness` which tests an implementation detail of the legacy funcol. We have equivalent tests for native funcol in `test/distributed/test_c10d_functional_native.py` b7fac76fc2/test/distributed/test_c10d_functional_native.py (L114-L116)
`test/distributed/_tensor/test_dtensor.py`
`test/distributed/_tensor/test_dtensor_compile.py`
`test/distributed/test_device_mesh.py`
`test/distributed/_tensor/experimental/test_tp_transform.py`
`test/distributed/_tensor/test_matrix_ops.py`
`test/distributed/test_inductor_collectives.py`
- All these tests were double running with both native funcol and legacy funcol. Changed to only run with native funcol.
`test/distributed/test_c10d_functional_native.py`
- Removed the `run_with_native_funcol` decorators.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/123777
Approved by: https://github.com/wanchaol
ghstack dependencies: #123776
Today `GroupRegistry` employs thread isolation by default, i.e. every thread sees its own process group registry. This is intended to work for one-device-per-process (for python use cases) and one-device-per-thread case (for custom native runtimes).
However, there's a problem - there are python use cases that initializes/registers process groups in one thread, and runs collectives in another thread. This use case should be supported. However, since `GroupRegistry` employs thread isolation by default, collectives in different threads can't find the registered process groups.
This PR fixes the issue by:
- Make `GroupRegistry` work in non-thread isolation mode by default. This would match the behavior w/o the native process group registry.
- Introduces `set_thread_isolation_mode` so one-device-per-thread runtimes can enable thread isolation mode explicitly.
Differential Revision: [D54658515](https://our.internmc.facebook.com/intern/diff/D54658515)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/121457
Approved by: https://github.com/wanchaol
Previous, we parametrize some tests to run with both native and py funcol by flipping a global variable. However, some of these tests are multi-threaded tests, and the parametrization mechanism could lead to race condition.
This PR changes the mechansim to use `mock.patch` which is applied on a per-thread basis.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120833
Approved by: https://github.com/wconstab
```
Between the time we switch to the native funcol by default and the time when
we are confident that we can remove the legacy implementation, we want to
ensure that the legacy funcol remains covered by unit tests. This is to
prepare for any potential (but unlikely) reverts. The following utilities
help achieve this goal.
run_with_{native,legacy}_funcol - mark a test to run with only
{native,legacy} funcol. These decorators are for impl specific tests (e.g.
verifying generated code with FileCheck).
run_with_both_funcol_impls - parametrize a test to run with both legacy and
native funcol.
run_with_both_funcol_impls_with_arg - same as run_with_both_funcol_impls, but
passes `enable_native_funcol` to the test so impl specific checks can be
carried out.
```
This PR also marks some tests we want to cover in this fashion. More tests will be marked in subsequent PRs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/119950
Approved by: https://github.com/wanchaol
ghstack dependencies: #119881
This is a lot of files changed! Don't panic! Here's how it works:
* Previously, we set `follow_imports = silent` for our mypy.ini configuration. Per https://mypy.readthedocs.io/en/stable/running_mypy.html#follow-imports, what this does is whenever we have an import to a module which is not listed as a file to be typechecked in mypy, we typecheck it as normal but suppress all errors that occurred in that file.
* When mypy is run inside lintrunner, the list of files is precisely the files covered by the glob in lintrunner.toml, but with files in excludes excluded.
* The top-level directive `# mypy: ignore-errors` instructs mypy to typecheck the file as normal, but ignore all errors.
* Therefore, it should be equivalent to set `follow_imports = normal`, if we put `# mypy: ignore-errors` on all files that were previously excluded from the file list.
* Having done this, we can remove the exclude list from .lintrunner.toml, since excluding a file from typechecking is baked into the files themselves.
* torch/_dynamo and torch/_inductor were previously in the exclude list, because they were covered by MYPYINDUCTOR. It is not OK to mark these as `# mypy: ignore-errors` as this will impede typechecking on the alternate configuration. So they are temporarily being checked twice, but I am suppressing the errors in these files as the configurations are not quite the same. I plan to unify the configurations so this is only a temporary state.
* There were some straggler type errors after these changes somehow, so I fixed them as needed. There weren't that many.
In the future, to start type checking a file, just remove the ignore-errors directive from the top of the file.
The codemod was done with this script authored by GPT-4:
```
import glob
exclude_patterns = [
...
]
for pattern in exclude_patterns:
for filepath in glob.glob(pattern, recursive=True):
if filepath.endswith('.py'):
with open(filepath, 'r+') as f:
content = f.read()
f.seek(0, 0)
f.write('# mypy: ignore-errors\n\n' + content)
```
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118414
Approved by: https://github.com/thiagocrepaldi, https://github.com/albanD
This replaces a bunch of unnecessary lambdas with the operator package. This is semantically equivalent, but the operator package is faster, and arguably more readable. When the FURB rules are taken out of preview, I will enable it as a ruff check.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/116027
Approved by: https://github.com/malfet
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
This test(8340762211/test/distributed/test_multi_threaded_pg.py (L133) ) is failing on internal sandbox with the following error msg:
```
File "/data/sandcastle/boxes/eden-trunk-hg-fbcode-fbsource/buck-out/v2/gen/fbcode/8c7462494077df89/caffe2/test/distributed/__multi_threaded__/multi_threaded#link-tree/torch/testing/_internal/distributed/multi_threaded_pg.py", line 255, in _start_coll
raise Exception(
Exception: world not ready, only 3 PG's registered but world has 4 ranks
exiting thread 1
ERROR
```
Internal error report: https://www.internalfb.com/intern/test/562950031915334?ref_report_id=0
We believe this is because we no longer perform barrier after init (see https://github.com/pytorch/pytorch/pull/99937).
This PR temporarily turn back on ```TORCH_DIST_INIT_BARRIER``` to avoid flaky test for the time being, but we should look into it to find a way to properly do this.
cc. @kumpera @kwen2501
Pull Request resolved: https://github.com/pytorch/pytorch/pull/103568
Approved by: https://github.com/H-Huang
