Use legacy logic + add to benchmark to avoid regression (#1969)

Summary:
Pull Request resolved: #1969

PrefetchTrainPipelineSparseDist - use legacy TrainPipeline API and will refactor newer internals assuming memory neutral / or better.

Reviewed By: henrylhtsang

Differential Revision: D57143337

fbshipit-source-id: 37df010a3e2fe16365b1190367869016ab386f72

Author: dstaay-fb

torchrec/distributed/train_pipeline/tests/pipeline_benchmarks.py

@@ -36,7 +36,10 @@
     TrainPipelineBase,
     TrainPipelineSparseDist,
 )
-from torchrec.distributed.train_pipeline.train_pipelines import TrainPipelineSemiSync
+from torchrec.distributed.train_pipeline.train_pipelines import (
+    PrefetchTrainPipelineSparseDist,
+    TrainPipelineSemiSync,
+)
 from torchrec.distributed.types import ModuleSharder, ShardingEnv, ShardingType
 from torchrec.modules.embedding_configs import EmbeddingBagConfig
 
@@ -260,6 +263,7 @@ def runner(
             TrainPipelineBase,
             TrainPipelineSparseDist,
             TrainPipelineSemiSync,
+            PrefetchTrainPipelineSparseDist,
         ]:
             pipeline = pipeline_clazz(
                 model=sharded_model,

torchrec/distributed/train_pipeline/train_pipelines.py

@@ -197,26 +197,26 @@ def __init__(
         self._batch_ip2: Optional[In] = None
         self._context: TrainPipelineContext = context_type(version=0)
 
+    def _set_module_context(self, context: TrainPipelineContext) -> None:
+        for module in self._pipelined_modules:
+            module.forward.set_context(context)
+
     def enqueue_batch(self, dataloader_iter: Iterator[In]) -> bool:
         batch, context = self.copy_batch_to_gpu(dataloader_iter)
         if batch is None:
             return False
         self.batches.append(batch)
         # pyre-ignore [6]
         self.contexts.append(context)
+
         return True
 
     def dequeue_batch(self) -> None:
         self.batches.popleft()
         self.contexts.popleft()
         # update PipelineForwards context to match next forward pass
         if len(self.batches) >= 1:
-            for module in self._pipelined_modules:
-                module.forward.set_context(self.contexts[0])
-
-            # legacy support
-            self._context = self.contexts[0]
-            self._context.version = 0
+            self._set_module_context(self.contexts[0])
 
     def fill_pipeline(self, dataloader_iter: Iterator[In]) -> None:
         # pipeline is already filled
@@ -247,6 +247,9 @@ def progress(self, dataloader_iter: Iterator[In]) -> Out:
         if not self.batches:
             raise StopIteration
 
+        # TODO: Remove once Bulk Eval migrated (needed for bwd compat, this class only)
+        self._set_module_context(self.contexts[0])
+
         if self._model.training:
             with record_function("## zero_grad ##"):
                 self._optimizer.zero_grad()
@@ -298,8 +301,7 @@ def _init_pipelined_modules(
         the splits collective in the input dist.
         """
         if self._pipelined_modules:
-            for module in self._pipelined_modules:
-                module.forward.set_context(context)
+            self._set_module_context(context)
             self.start_sparse_data_dist(batch, context)
             return
 
@@ -385,6 +387,7 @@ def _copy_batch_to_gpu(self, dataloader_iter: Iterator[In]) -> Optional[In]:
         """
         DEPRECATED: exists for backward compatibility on TrainPipelineContext.version 0
         """
+        self._set_module_context(self._context)
         batch, _ = self.copy_batch_to_gpu(dataloader_iter)
         return batch
 
@@ -393,6 +396,7 @@ def _start_sparse_data_dist(self, batch: Optional[In]) -> None:
         DEPRECATED: exists for backward compatibility
         Waits for batch to finish getting copied to GPU, then starts the input dist.
         """
+        self._set_module_context(self._context)
         self.start_sparse_data_dist(batch, self._context)
 
     def _wait_sparse_data_dist(self) -> None:
@@ -401,7 +405,7 @@ def _wait_sparse_data_dist(self) -> None:
         Waits on the input dist splits requests to get the input dist tensors requests,
         and populates the context with them.
         """
-        assert self._context.version == 0, "Context version == 0 is required"
+        self._set_module_context(self._context)
         with record_function("## wait_sparse_data_dist ##"):
             with torch.cuda.stream(self._data_dist_stream):
                 self._context.module_contexts = (
@@ -676,73 +680,67 @@ def __init__(
             apply_jit=apply_jit,
             context_type=PrefetchTrainPipelineContext,
         )
+        self._context = PrefetchTrainPipelineContext(version=0)
         self._prefetch_stream: Optional[torch.cuda.streams.Stream] = (
             (torch.cuda.Stream()) if self._device.type == "cuda" else None
         )
         self._default_stream: Optional[torch.cuda.streams.Stream] = (
             (torch.cuda.Stream()) if self._device.type == "cuda" else None
         )
+        self._batch_ip3: Optional[In] = None
 
-    def fill_pipeline(self, dataloader_iter: Iterator[In]) -> None:
-        # pipeline is full
-        if len(self.batches) >= 3:
+    def _fill_pipeline(self, dataloader_iter: Iterator[In]) -> None:
+        # pipeline is already filled
+        if self._batch_i and self._batch_ip1 and self._batch_ip2:
             return
-        # executes last batch(es) in pipeline
-        if self.batches and self._execute_all_batches:
+        # executes last batch in pipeline
+        if self._execute_all_batches and (self._batch_i or self._batch_ip1):
             return
 
-        # batch 0
-        if not self.enqueue_batch(dataloader_iter):
-            return
+        # batch 1
+        self._batch_i = self._copy_batch_to_gpu(dataloader_iter)
+        if self._batch_i is None:
+            raise StopIteration
+
         self._init_pipelined_modules(
-            # pyre-ignore [6]
-            self.batches[0],
-            self.contexts[0],
-            # pyre-ignore [6]
+            self._batch_i,
+            self._context,
+            # pyre-ignore
             PrefetchPipelinedForward,
         )
-        self.wait_sparse_data_dist(self.contexts[0])
-        self._prefetch(self.batches[0], self.contexts[0])
-
-        # batch 1
-        if not self.enqueue_batch(dataloader_iter):
-            return
-        self.start_sparse_data_dist(self.batches[1], self.contexts[1])
-        self.wait_sparse_data_dist(self.contexts[1])
+        self._start_sparse_data_dist(self._batch_i)
+        self._wait_sparse_data_dist()
+        self._prefetch(self._batch_i)
 
         # batch 2
-        if not self.enqueue_batch(dataloader_iter):
-            return
+        self._batch_ip1 = self._copy_batch_to_gpu(dataloader_iter)
+        self._start_sparse_data_dist(self._batch_ip1)
+        self._wait_sparse_data_dist()
+
+        # batch 3
+        self._batch_ip2 = self._copy_batch_to_gpu(dataloader_iter)
 
     def progress(self, dataloader_iter: Iterator[In]) -> Out:
-        self.fill_pipeline(dataloader_iter)
-        if not self.batches:
-            raise StopIteration
+        self._fill_pipeline(dataloader_iter)
 
         if self._model.training:
             with record_function("## zero_grad ##"):
                 self._optimizer.zero_grad()
 
         with record_function("## wait_for_batch ##"):
-            _wait_for_batch(cast(In, self.batches[0]), self._prefetch_stream)
+            _wait_for_batch(cast(In, self._batch_i), self._prefetch_stream)
 
-        if len(self.batches) >= 3:
-            self.start_sparse_data_dist(self.batches[2], self.contexts[2])
+        self._start_sparse_data_dist(self._batch_ip2)
 
-        # batch 3
-        self.enqueue_batch(dataloader_iter)
+        self._batch_ip3 = self._copy_batch_to_gpu(dataloader_iter)
 
         # forward
         with record_function("## forward ##"):
-            losses, output = cast(
-                Tuple[torch.Tensor, Out], self._model(self.batches[0])
-            )
+            losses, output = cast(Tuple[torch.Tensor, Out], self._model(self._batch_i))
 
-        if len(self.batches) >= 2:
-            self._prefetch(self.batches[1], self.contexts[1])
+        self._prefetch(self._batch_ip1)
 
-        if len(self.batches) >= 3:
-            self.wait_sparse_data_dist(self.contexts[2])
+        self._wait_sparse_data_dist()
 
         if self._model.training:
             # backward
@@ -753,24 +751,30 @@ def progress(self, dataloader_iter: Iterator[In]) -> Out:
             with record_function("## optimizer ##"):
                 self._optimizer.step()
 
-        self.dequeue_batch()
+        self._batch_i = self._batch_ip1
+        self._batch_ip1 = self._batch_ip2
+        self._batch_ip2 = self._batch_ip3
+
         return output
 
-    def _prefetch(self, batch: Optional[In], context: TrainPipelineContext) -> None:
+    def _prefetch(self, batch: Optional[In]) -> None:
         """
         Waits for input dist to finish, then prefetches data.
         """
         if batch is None:
             return
-        with record_function(f"## sharded_module_prefetch {context.index} ##"):
+        self._context.module_input_post_prefetch.clear()
+        self._context.module_contexts_post_prefetch.clear()
+
+        with record_function("## sharded_module_prefetch ##"):
             with torch.cuda.stream(self._prefetch_stream):
                 batch.record_stream(torch.cuda.current_stream())
                 for sharded_module in self._pipelined_modules:
                     forward = sharded_module.forward
                     assert isinstance(forward, PrefetchPipelinedForward)
 
-                    assert forward._name in context.input_dist_tensors_requests
-                    request = context.input_dist_tensors_requests[forward._name]
+                    assert forward._name in self._context.input_dist_tensors_requests
+                    request = self._context.input_dist_tensors_requests[forward._name]
                     assert isinstance(request, Awaitable)
                     with record_function("## wait_sparse_data_dist ##"):
                         # Finish waiting on the dist_stream,
@@ -790,16 +794,16 @@ def _prefetch(self, batch: Optional[In], context: TrainPipelineContext) -> None:
                         data.record_stream(cur_stream)
                         data.record_stream(self._default_stream)
 
-                        module_context = context.module_contexts[forward._name]
-                        module_context.record_stream(cur_stream)
-                        module_context.record_stream(self._default_stream)
+                        ctx = self._context.module_contexts[forward._name]
+                        ctx.record_stream(cur_stream)
+                        ctx.record_stream(self._default_stream)
 
                     sharded_module.prefetch(
                         dist_input=data, forward_stream=self._default_stream
                     )
-                    context.module_input_post_prefetch[forward._name] = data
-                    context.module_contexts_post_prefetch[forward._name] = (
-                        context.module_contexts[forward._name]
+                    self._context.module_input_post_prefetch[forward._name] = data
+                    self._context.module_contexts_post_prefetch[forward._name] = (
+                        self._context.module_contexts[forward._name]
                     )