[PyTorch] Bunch of memory management fixes (#1686)

* init
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

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* fixes
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

* clear() fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

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* lint fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

* revert adding cpu offload tests for mxfp8
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

* fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

* fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

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* fixes
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

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* fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

* fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

* fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

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* fix
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

* forgot to uncomment assert
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>

---------
Signed-off-by: Pawel Gadzinski <pgadzinski@nvidia.com>
Co-authored-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

tests/pytorch/test_sanity.py

@@ -366,7 +366,9 @@ def _test_sanity_e2e_T5(block, dtype, config, fp8_recipe, skip_wgrad):
     torch.cuda.synchronize()
 
 
-def _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad):
+def _test_sanity_common(
+    block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad, microbatching=True
+):
     if skip_dgrad and skip_wgrad:
         pytest.skip("No gradient computation; Skipping to avoid PyTorch RuntimeError.")
 
@@ -382,7 +384,11 @@ def _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad
 
     use_fp8 = fp8_recipe is not None
     with fp8_autocast(enabled=use_fp8, fp8_recipe=fp8_recipe):
+        if not microbatching:
             te_out = block(te_inp)
+        else:
+            _ = block(te_inp, is_first_microbatch=True)
+            te_out = block(te_inp, is_first_microbatch=False)
     if isinstance(te_out, tuple):
         te_out = te_out[0]
     loss = te_out.sum()
@@ -436,8 +442,16 @@ def test_sanity_normalization_amp(dtype, model, skip_wgrad, skip_dgrad, normaliz
 @pytest.mark.parametrize("zero_centered_gamma", all_boolean)
 @pytest.mark.parametrize("skip_dgrad", all_boolean)
 @pytest.mark.parametrize("normalization", all_normalizations)
+@pytest.mark.parametrize("microbatching", all_boolean)
 def test_sanity_layernorm_linear(
-    dtype, fp8_recipe, model, skip_wgrad, zero_centered_gamma, skip_dgrad, normalization
+    dtype,
+    fp8_recipe,
+    model,
+    skip_wgrad,
+    zero_centered_gamma,
+    skip_dgrad,
+    normalization,
+    microbatching,
 ):
     config = model_configs[model]
 
@@ -463,7 +477,7 @@ def test_sanity_layernorm_linear(
         params_dtype=dtype,
         device="cuda",
     )
-    _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad)
+    _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad, microbatching)
 
 
 @pytest.mark.parametrize("dtype", param_types)
@@ -471,7 +485,8 @@ def test_sanity_layernorm_linear(
 @pytest.mark.parametrize("model", ["small", "weird"])
 @pytest.mark.parametrize("skip_wgrad", all_boolean)
 @pytest.mark.parametrize("skip_dgrad", all_boolean)
-def test_sanity_linear(dtype, fp8_recipe, model, skip_wgrad, skip_dgrad):
+@pytest.mark.parametrize("microbatching", all_boolean)
+def test_sanity_linear(dtype, fp8_recipe, model, skip_wgrad, skip_dgrad, microbatching):
     config = model_configs[model]
 
     if fp8_recipe is not None:
@@ -494,7 +509,7 @@ def test_sanity_linear(dtype, fp8_recipe, model, skip_wgrad, skip_dgrad):
         params_dtype=dtype,
         device="cuda",
     )
-    _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad)
+    _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad, microbatching)
 
 
 @pytest.mark.parametrize("dtype", param_types)
@@ -593,8 +608,17 @@ def test_sanity_grouped_linear(
 @pytest.mark.parametrize("skip_dgrad", all_boolean)
 @pytest.mark.parametrize("activation", all_activations)
 @pytest.mark.parametrize("normalization", all_normalizations)
+@pytest.mark.parametrize("microbatching", all_boolean)
 def test_sanity_layernorm_mlp(
-    dtype, fp8_recipe, model, skip_wgrad, zero_centered_gamma, skip_dgrad, activation, normalization
+    dtype,
+    fp8_recipe,
+    model,
+    skip_wgrad,
+    zero_centered_gamma,
+    skip_dgrad,
+    activation,
+    normalization,
+    microbatching,
 ):
     config = model_configs[model]
 
@@ -623,7 +647,7 @@ def test_sanity_layernorm_mlp(
         params_dtype=dtype,
         device="cuda",
     )
-    _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad)
+    _test_sanity_common(block, dtype, config, fp8_recipe, skip_wgrad, skip_dgrad, microbatching)
 
 
 @pytest.mark.parametrize("dtype", param_types)

transformer_engine/pytorch/module/base.py

@@ -1106,7 +1106,16 @@ class TransformerEngineBaseModule(torch.nn.Module, ABC):
                 raise ValueError(
                     "tensor and quantizer kwargs must be provided to construct FP8 workspace"
                 )
+
+            if cache_name is not None:
+                # Ensure the tensor in the cache is an instance of torch.Tensor,
+                # as it persists beyond a single forward pass.
+                # Setting internal=True would cause the data to be removed in prepare_for_saving(...).
+                quantizer_internal = quantizer.internal
+                quantizer.internal = False
             out = quantizer.quantize(tensor, dtype=workspace_dtype)
+            if cache_name is not None:
+                quantizer.internal = quantizer_internal
 
             # Update cache
             if cache_name is not None:

transformer_engine/pytorch/module/layernorm_linear.py

@@ -137,8 +137,10 @@ class _LayerNormLinear(torch.autograd.Function):
         # Make sure input dimensions are compatible
         out_features, in_features = weight.shape
         inp_shape = inp.shape
+        inp_requires_grad = inp.requires_grad
         assert inp_shape[-1] == in_features, "GEMM not possible"
-        inputmat = inp.view((-1, in_features))
+        inp = inp.view((-1, in_features))
+        inputmat = inp
         if fp8:
             assert_dim_for_fp8_exec(inputmat, weight)
 
@@ -399,7 +401,7 @@ class _LayerNormLinear(torch.autograd.Function):
             )
             ctx.save_for_backward(*tensors_to_save)
             ctx.tensor_objects = tensor_objects
-            ctx.requires_dgrad = inp.requires_grad
+            ctx.requires_dgrad = inp_requires_grad
             ctx.requires_wgrad = weight.requires_grad
             ctx.quantized_weight = quantized_weight
             if fuse_wgrad_accumulation and weight.requires_grad:
@@ -432,7 +434,7 @@ class _LayerNormLinear(torch.autograd.Function):
             ctx.ub_bulk_wgrad = ub_bulk_wgrad
             ctx.ub_bulk_dgrad = ub_bulk_dgrad
             ctx.ub_name = ub_name
-            ctx.requires_dgrad = inp.requires_grad
+            ctx.requires_dgrad = inp_requires_grad
             ctx.normalization = normalization
             ctx.reduce_and_update_bwd_fp8_tensors = False
             if ctx.fp8 and requires_grad(inp, ln_weight, ln_bias, weight, bias):
@@ -462,7 +464,7 @@ class _LayerNormLinear(torch.autograd.Function):
 
         if return_layernorm_output:
             if return_layernorm_output_gathered:
-                shape = list(inp.shape)
+                shape = list(inp_shape)
                 shape[0] *= tp_size
                 return out, ln_out_return.view(shape)
             return out, ln_out_return.view_as(inp)

transformer_engine/pytorch/module/linear.py

@@ -126,8 +126,7 @@ class _Linear(torch.autograd.Function):
 
         # Make sure input dimensions are compatible
         out_features, in_features = weight.shape
-        inp_shape = inp.shape
-        assert inp_shape[-1] == in_features, "GEMM not possible"
+        assert inp.shape[-1] == in_features, "GEMM not possible"
 
         tp_world_size = get_distributed_world_size(tp_group)
         backward_needs_input = is_grad_enabled and weight.requires_grad
@@ -135,7 +134,8 @@ class _Linear(torch.autograd.Function):
         # Prepare input tensor
         # Note: Cast to expected dtype and perform tensor-parallel communication
         nvtx_range_push(f"{nvtx_label}.input_cast_comm")
-        inputmat = inp.view(-1, in_features)
+
+        inputmat = inp
         inputmat_total = None
         with_input_all_gather_nccl = (
             parallel_mode == "column" and sequence_parallel and not ub_overlap_ag_fprop
@@ -256,7 +256,7 @@ class _Linear(torch.autograd.Function):
         if ub_overlap_rs_fprop:
             ub_obj = get_ub(ub_name + "_fprop")
             ub_type = tex.CommOverlapType.RS
-            out_shape = [reduce(multiply_op, inp_shape[:-1]) // tp_world_size, out_features]
+            out_shape = [reduce(multiply_op, inp.shape[:-1]) // tp_world_size, out_features]
             rs_out = torch.empty(out_shape, dtype=activation_dtype, device=inputmat_total.device)
 
         elif ub_overlap_ag_fprop:
@@ -365,7 +365,7 @@ class _Linear(torch.autograd.Function):
             ctx.use_bias = bias is not None
             ctx.sequence_parallel = sequence_parallel
             ctx.tensor_parallel = tensor_parallel
-            ctx.inp_shape = inp_shape
+            ctx.inp_shape = inp.shape
             ctx.parallel_mode = parallel_mode
             ctx.tp_group = tp_group
             ctx.ub_overlap_ag = ub_overlap_ag_dgrad
@@ -377,6 +377,7 @@ class _Linear(torch.autograd.Function):
             ctx.requires_dgrad = inp.requires_grad
             ctx.requires_wgrad = weight.requires_grad
             ctx.reduce_and_update_bwd_fp8_tensors = False
+
             ctx.owns_input = saved_inputmat is not inp
             if ctx.fp8 and requires_grad(inp, weight, bias):
                 _first_fp8_module = FP8GlobalStateManager.IS_FIRST_FP8_MODULE
@@ -399,7 +400,6 @@ class _Linear(torch.autograd.Function):
                     out, _ = allreduce(out, tp_group)
             nvtx_range_pop(f"{nvtx_label}.row_parallel_comm")
 
-        out = out.view(-1, *inp_shape[1:-1], out_features)
         return out
 
     @staticmethod

transformer_engine/pytorch/tensor/_internal/float8_blockwise_tensor_base.py

@@ -57,6 +57,17 @@ class Float8BlockwiseQTensorBase:
 
         return instance
 
+    def clear(self):
+        """Deallocate this tensor's memory. Typically not needed and must be used carefully."""
+        for t in (
+            self._rowwise_data,
+            self._columnwise_data,
+            self._rowwise_scale_inv,
+            self._columnwise_scale_inv,
+        ):
+            if t is not None:
+                t.data = torch.Tensor()
+
     def get_metadata(self) -> Dict[str, Any]:
         """Get this tensor's metadata."""
         return {
@@ -74,14 +85,17 @@ class Float8BlockwiseQTensorBase:
     ) -> Tuple[list[Optional[torch.Tensor]], Float8BlockwiseQTensorBase]:
         """
         Prepare the tensor base for saving for backward
-
-        This does not clear the tensors currently, because with PP config
-        that clears the weight cache between micro-batches. If the rowwise
-        data is not required for backward, this is a possible memory
-        pessimization, but is consistent with the other quantized tensor
-        classes.
         """
-        tensors = [self._rowwise_data, self._columnwise_data]
+        tensors = [
+            self._rowwise_data,
+            self._columnwise_data,
+            self._rowwise_scale_inv,
+            self._columnwise_scale_inv,
+        ]
+        self._rowwise_data = None
+        self._columnwise_data = None
+        self._rowwise_scale_inv = None
+        self._columnwise_scale_inv = None
         return tensors, self
 
     def restore_from_saved(
@@ -90,7 +104,9 @@ class Float8BlockwiseQTensorBase:
         """Restore the tensor base data from the saved tensors list."""
         self._rowwise_data = tensors[0]
         self._columnwise_data = tensors[1]
-        return tensors[2:]
+        self._rowwise_scale_inv = tensors[2]
+        self._columnwise_scale_inv = tensors[3]
+        return tensors[4:]
 
     def get_data_tensors(self):
         """Get this Tensor's data."""

transformer_engine/pytorch/tensor/_internal/float8_tensor_base.py

@@ -90,6 +90,13 @@ class Float8TensorBase:
 
         return instance
 
+    def clear(self):
+        """Deallocate this tensor's memory. Typically not needed and must be used carefully."""
+        for t in (self._data, self._transpose, self._scale_inv):
+            if t is not None:
+                t.data = torch.Tensor()
+        self._transpose_invalid = True
+
     def get_metadata(self) -> Dict[str, Any]:
         """Get this tensor's metadata."""
         return {
@@ -102,7 +109,10 @@ class Float8TensorBase:
 
     def prepare_for_saving(self) -> Tuple[list[Optional[torch.Tensor]], Float8TensorBase]:
         """Prepare the tensor base for saving for backward"""
-        tensors = [self._data, self._transpose]
+        tensors = [self._data, self._transpose, self._scale_inv]
+        self._data = None
+        self._transpose = None
+        self._scale_inv = None
         return tensors, self
 
     def restore_from_saved(
@@ -111,7 +121,8 @@ class Float8TensorBase:
         """Restore the tensor base data from the saved tensors list"""
         self._data = tensors[0]
         self._transpose = tensors[1]
-        return tensors[2:]
+        self._scale_inv = tensors[2]
+        return tensors[3:]
 
     def get_data_tensors(self):
         """Get this Tensor's data."""

transformer_engine/pytorch/tensor/_internal/mxfp8_tensor_base.py

@@ -81,6 +81,17 @@ class MXFP8TensorBase:
 
         return instance
 
+    def clear(self):
+        """Deallocate this tensor's memory. Typically not needed and must be used carefully."""
+        for t in (
+            self._rowwise_data,
+            self._columnwise_data,
+            self._rowwise_scale_inv,
+            self._columnwise_scale_inv,
+        ):
+            if t is not None:
+                t.data = torch.Tensor()
+
     def get_metadata(self) -> Dict[str, Any]:
         """Get this tensor's metadata."""
         return {
@@ -94,7 +105,16 @@ class MXFP8TensorBase:
 
     def prepare_for_saving(self) -> Tuple[list[Optional[torch.Tensor]], MXFP8TensorBase]:
         """Prepare the tensor base for saving for backward"""
-        tensors = [self._rowwise_data, self._columnwise_data]
+        tensors = [
+            self._rowwise_data,
+            self._columnwise_data,
+            self._rowwise_scale_inv,
+            self._columnwise_scale_inv,
+        ]
+        self._rowwise_data = None
+        self._columnwise_data = None
+        self._rowwise_scale_inv = None
+        self._columnwise_scale_inv = None
         return tensors, self
 
     def restore_from_saved(
@@ -103,7 +123,9 @@ class MXFP8TensorBase:
         """Restore the tensor base data from the saved tensors list."""
         self._rowwise_data = tensors[0]
         self._columnwise_data = tensors[1]
-        return tensors[2:]
+        self._rowwise_scale_inv = tensors[2]
+        self._columnwise_scale_inv = tensors[3]
+        return tensors[4:]
 
     def get_data_tensors(self):
         """Get this Tensor's data."""

transformer_engine/pytorch/tensor/float8_blockwise_tensor.py

@@ -432,11 +432,6 @@ class Float8BlockwiseQTensor(Float8BlockwiseQTensorBase, QuantizedTensor):
             return self
         raise ValueError("Float8BlockwiseQTensor does not support different memory formats!")
 
-    def clear(self):
-        """Deallocate this tensor's memory. Typically not needed and must be used carefully."""
-        self._rowwise_data = torch.Tensor() if self._rowwise_data is not None else None
-        self._columnwise_data = torch.Tensor() if self._columnwise_data is not None else None
-
     @classmethod
     def _make_in_reduce_ex(
         cls,

transformer_engine/pytorch/tensor/float8_tensor.py

@@ -516,12 +516,6 @@ class Float8Tensor(Float8TensorBase, QuantizedTensor):
         del self._transpose  # explicitly deletes the data for safety
         self._transpose = None
 
-    def clear(self):
-        """Deallocate this tensor's memory. Typically not needed and must be used carefully."""
-        self._data = torch.Tensor() if self._data is not None else None
-        self._transpose = torch.Tensor() if self._transpose is not None else None
-        self._transpose_invalid = True
-
     @classmethod
     def __torch_dispatch__(cls, func, types, args, kwargs=None):
 

transformer_engine/pytorch/tensor/mxfp8_tensor.py

@@ -304,11 +304,6 @@ class MXFP8Tensor(MXFP8TensorBase, QuantizedTensor):
             return self
         raise ValueError("MXFP8Tensor does not support different memory formats!")
 
-    def clear(self):
-        """Deallocate this tensor's memory. Typically not needed and must be used carefully."""
-        self._rowwise_data = torch.Tensor() if self._rowwise_data is not None else None
-        self._columnwise_data = torch.Tensor() if self._columnwise_data is not None else None
-
     @classmethod
     def __torch_dispatch__(cls, func, types, args, kwargs=None):
 

transformer_engine/pytorch/utils.py

@@ -14,8 +14,6 @@ import torch
 import transformer_engine.pytorch.cpp_extensions as ext
 from ..debug.pytorch.debug_quantization import DebugQuantizedTensor
 
-from .tensor.quantized_tensor import QuantizedTensor
-
 
 def requires_grad(*tensors: Tuple[Optional[torch.Tensor], ...]) -> None:
     """Check if any of the given tensors require gradient."""
@@ -34,7 +32,7 @@ def clear_tensor_data(*tensors: Tuple[Optional[torch.Tensor], ...]) -> None:
     """
     for t in tensors:
         if t is not None:
-            if isinstance(t, QuantizedTensor):
+            if hasattr(t, "clear"):
                 t.clear()
             else:
                 t.data = torch.Tensor()
@@ -421,10 +419,10 @@ def assert_dim_for_fp8_exec(*tensors: List[torch.Tensor]) -> None:
     """Assert that tensor or tensors dimensions are supported for FP8 TN GEMM."""
 
     for tensor in tensors:
-        assert tensor.dim() == 2 and tensor.size(0) % 8 == 0 and tensor.size(1) % 16 == 0, (
-            "FP8 execution requires 2D input matrices with "
-            "height divisible by 8 and width divisible by 16, "
-            f"but got tensor with dims={list(tensor.size())}"
+        assert math.prod(tensor.shape[:-1]) % 8 == 0 and tensor.shape[-1] % 16 == 0, (
+            "FP8 execution requires the product of all dimensions except the last to be divisible"
+            " by 8 and the last dimension to be divisible by 16, but got tensor with"
+            f" dims={list(tensor.size())}"
         )