Fix TE ops API compatibility with PyTorch versions < 2.4.3 (#1494)

* Fix te sequential for older pytorch versions
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

* FIxes
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

---------
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

tests/pytorch/distributed/test_torch_fsdp2.py

@@ -7,19 +7,9 @@ import pytest
 import subprocess
 from pathlib import Path
 from transformer_engine.pytorch.fp8 import FP8GlobalStateManager
-import torch
-from packaging.version import Version as PkgVersion
-
-
-def get_torch_version():
-    """Get PyTorch version from __version__"""
+from transformer_engine.pytorch.utils import torch_version
 
-    def get_torch_version_str():
-        import torch
-
-        return str(torch.__version__)
-
-    return PkgVersion(get_torch_version_str())
+import torch
 
 
 fp8_available, reason_for_no_fp8 = FP8GlobalStateManager.is_fp8_available()
@@ -44,7 +34,7 @@ def _run_test(fp_init, sharding_dims):
 
 @pytest.mark.skipif(NUM_PROCS < 4, reason="Requires 4+ GPUs")
 @pytest.mark.skipif(NUM_PROCS % 2 != 0, reason="Requires even number of GPUs")
-@pytest.mark.skipif(not get_torch_version() >= PkgVersion("2.4"), reason="Requires PyTorch 2.4.0+")
+@pytest.mark.skipif(not torch_version() >= (2, 4, 0), reason="Requires PyTorch 2.4.0+")
 @pytest.mark.parametrize("sharding_dims", ([NUM_PROCS], [2, NUM_PROCS // 2]))
 @pytest.mark.parametrize("fp8_init", (False, True))
 def test_distributed(fp8_init, sharding_dims):

transformer_engine/pytorch/ops/_common.py

@@ -16,6 +16,7 @@ from ..utils import (
     canonicalize_device,
     canonicalize_dtype,
     devices_match,
+    torch_version,
 )
 
 
@@ -98,8 +99,13 @@ def maybe_autocast_dtype(
     default_dtype: Optional[torch.dtype] = None,
 ) -> torch.dtype:
     """Get autocast dtype if enabled"""
+
+    if torch_version() >= (2, 4, 3):
         if torch.is_autocast_enabled(device_type):
             return torch.get_autocast_dtype(device_type)
+    else:
+        if torch.is_autocast_enabled():
+            return torch.get_autocast_gpu_dtype()
     return canonicalize_dtype(default_dtype)
 
 

transformer_engine/pytorch/utils.py

@@ -8,6 +8,7 @@ import functools
 import math
 import os
 from typing import Any, Callable, List, Optional, Tuple
+from packaging.version import Version as PkgVersion
 
 import torch
 import transformer_engine.pytorch.cpp_extensions as ext
@@ -386,3 +387,9 @@ def nvtx_range_pop(msg: Optional[str] = None) -> None:
 
     # Pop NVTX range
     torch.cuda.nvtx.range_pop()
+
+
+@functools.lru_cache(maxsize=None)
+def torch_version() -> tuple[int, ...]:
+    """Get PyTorch version"""
+    return PkgVersion(str(torch.__version__)).release