[shardformer] hybridparallelplugin support gradients accumulation. (#5246)

* support gradients acc

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colossalai/booster/plugin/hybrid_parallel_plugin.py

@@ -165,7 +165,6 @@ class HybridParallelModule(ModelWrapper, AMPModelMixin):
         Returns:
             None
         """
-
         if self.tp_group.size() > 1 and self.shard_config.enable_sequence_parallelism:
             if grads is not None:
                 # Synchronize provided gradient tensors across the tensor parallelism group.
@@ -487,7 +486,6 @@ class HybridParallelAMPOptimizer(MixedPrecisionOptimizer):
         Returns:
             None
         """
-
         # Call the superclass backward method to compute gradients.
         super().backward(loss, *args, **kwargs)
 
@@ -513,7 +511,6 @@ class HybridParallelAMPOptimizer(MixedPrecisionOptimizer):
         Returns:
             None
         """
-
         # Call the superclass backward method to compute gradients.
         super().backward_by_grad(tensor, grad)
 
@@ -674,7 +671,6 @@ class HybridParallelZeroOptimizer(LowLevelZeroOptimizer):
         Returns:
             None
         """
-
         # Call the superclass `_sync_grad` method to synchronize gradients.
         super()._sync_grad()
 
@@ -1081,7 +1077,7 @@ class HybridParallelPlugin(PipelinePluginBase):
         return True
 
     def support_no_sync(self) -> bool:
-        return False
+        return True
 
     def control_checkpoint_io(self) -> bool:
         return True
@@ -1175,9 +1171,14 @@ class HybridParallelPlugin(PipelinePluginBase):
                 model, data_iter, criterion, optimizer, return_loss, return_outputs
             )
 
+        # run with gradients accumulation
+        if model.require_grad_sync == False or (
+            isinstance(optimizer, HybridParallelZeroOptimizer) and optimizer.require_grad_sync == False
+        ):
+            return outputs
+
         # Synchronize the grads of shared parameters of the model.
         model.sync_shared_params()
-
         # Synchronize sequence parallelism gradients of the model.
         model.sync_sp_grads()
 
@@ -1241,5 +1242,8 @@ class HybridParallelPlugin(PipelinePluginBase):
     def get_checkpoint_io(self) -> CheckpointIO:
         return HybridParallelCheckpointIO(self.dp_group, self.pp_group, self.tp_group, self.zero_stage)
 
-    def no_sync(self, model: Module) -> Iterator[None]:
+    def no_sync(self, model: Module, optimizer: OptimizerWrapper) -> Iterator[None]:
-        raise NotImplementedError
+        assert (
+            self.zero_stage != 2
+        ), "ZERO2 is not compatible with no_sync function, please run gradient accumulation with gradient synchronization allowed."
+        return optimizer.no_sync() if isinstance(optimizer, HybridParallelZeroOptimizer) else model.no_sync()

tests/test_booster/test_plugin/test_3d_plugin.py

@@ -1,8 +1,11 @@
+import copy
 from contextlib import nullcontext
 from typing import Optional
 
 import torch
 import torch.distributed as dist
+from torch.testing import assert_close
+from torch.utils.data import Dataset
 
 import colossalai
 from colossalai.booster import Booster
@@ -11,9 +14,33 @@ from colossalai.fx import is_compatible_with_meta
 from colossalai.lazy.lazy_init import LazyInitContext
 from colossalai.nn.optimizer import HybridAdam
 from colossalai.testing import clear_cache_before_run, parameterize, rerun_if_address_is_in_use, spawn
+from colossalai.utils import get_current_device, set_seed
 from tests.kit.model_zoo import model_zoo
 
 
+class RandomDataset(Dataset):
+    def __init__(self, num_samples: int = 100, max_length: int = 512, vocab_size: int = 32000):
+        self.num_samples = num_samples
+        self.max_length = max_length
+        set_seed(42)
+        self.input_ids = torch.randint(0, vocab_size, (num_samples, max_length), device=get_current_device())
+        self.attention_mask = torch.ones_like(self.input_ids)
+
+    def __len__(self):
+        return self.num_samples
+
+    def __getitem__(self, idx):
+        return {
+            "input_ids": self.input_ids[idx],
+            "attention_mask": self.attention_mask[idx],
+            "labels": self.input_ids[idx],
+        }
+
+
+def move_to_cuda(batch):
+    return {k: v.cuda() for k, v in batch.items()}
+
+
 @clear_cache_before_run()
 def run_fn(init_method, model_fn, data_gen_fn, output_transform_fn) -> Optional[str]:
     try:
@@ -85,10 +112,145 @@ def check_3d_plugin(init_method: str = "none", early_stop: bool = True):
     assert len(failed_info) == 0, "\n".join([f"{k}: {v}" for k, v in failed_info.items()])
 
 
+@parameterize(
+    "test_args",
+    [
+        {
+            "batch_size": 8,
+            "num_steps": 4,
+            "tp": 2,
+            "pp": 2,
+            "pp_style": "1f1b",
+            "num_model_chunks": 1,
+            "num_microbatches": 4,
+            "zero": 0,
+            "precision": "fp16",
+            "initial_scale": 1,
+            "max_length": 512,
+            "gradient_accumulation_step": 2,
+        },
+        {
+            "batch_size": 8,
+            "num_steps": 4,
+            "tp": 1,
+            "pp": 2,
+            "pp_style": "1f1b",
+            "num_model_chunks": 1,
+            "num_microbatches": 4,
+            "zero": 1,
+            "precision": "fp16",
+            "initial_scale": 1,
+            "max_length": 512,
+            "gradient_accumulation_step": 2,
+        },
+        {
+            "batch_size": 1,
+            "num_steps": 4,
+            "tp": 2,
+            "pp": 1,
+            "pp_style": "1f1b",
+            "num_model_chunks": 1,
+            "num_microbatches": 1,
+            "zero": 2,
+            "precision": "fp16",
+            "initial_scale": 1,
+            "max_length": 512,
+            "gradient_accumulation_step": 2,
+        },
+        {
+            "batch_size": 1,
+            "num_steps": 4,
+            "tp": 2,
+            "pp": 1,
+            "pp_style": "1f1b",
+            "num_model_chunks": 1,
+            "num_microbatches": 1,
+            "zero": 0,
+            "precision": "fp16",
+            "initial_scale": 1,
+            "max_length": 512,
+            "gradient_accumulation_step": 2,
+        },
+    ],
+)
+def run_grad_acc_test(test_args):
+    model_fn, *_ = next(iter(model_zoo.get_sub_registry("transformers_gpt_lm").values()))
+    model = model_fn()
+    optimizer = HybridAdam(model.parameters())
+    origin_model = copy.deepcopy(model).cuda()
+    origin_optimizer = HybridAdam(origin_model.parameters())
+
+    plugin = HybridParallelPlugin(
+        tp_size=test_args["tp"],
+        pp_size=test_args["pp"],
+        pp_style=test_args["pp_style"],
+        zero_stage=test_args["zero"],
+        num_model_chunks=test_args["num_model_chunks"],
+        enable_fused_normalization=True,
+        num_microbatches=test_args["num_microbatches"],
+        precision=test_args["precision"],
+    )
+    booster = Booster(plugin=plugin)
+
+    dataset = RandomDataset(
+        num_samples=test_args["batch_size"] * test_args["num_steps"] * plugin.dp_size,
+        max_length=test_args["max_length"],
+        vocab_size=model.config.vocab_size,
+    )
+    dataloader = plugin.prepare_dataloader(dataset, batch_size=test_args["batch_size"], shuffle=True, drop_last=True)
+
+    model, optimizer, _, dataloader, _ = booster.boost(model, optimizer, dataloader=dataloader)
+
+    grad_accu_step = test_args["gradient_accumulation_step"]
+    for step, batch in enumerate(dataloader):
+        batch = move_to_cuda(batch)
+        # train origin model
+        origin_output = origin_model(**batch)
+        origin_loss = origin_output[0] / grad_accu_step
+        origin_loss.backward()
+
+        if (step + 1) % grad_accu_step != 0 and test_args["zero"] != 2:
+            ctx = booster.no_sync(model, optimizer)
+        else:
+            ctx = nullcontext()
+
+        with ctx:
+            if plugin.stage_manager is not None:
+                batch = iter([batch])
+                booster.execute_pipeline(
+                    batch,
+                    model,
+                    criterion=lambda outputs, inputs: outputs[0] / grad_accu_step,
+                    optimizer=optimizer,
+                    return_loss=False,
+                )
+            else:
+                outputs = model(**batch)
+                loss = outputs[0] / grad_accu_step
+                booster.backward(loss, optimizer)
+
+        if (step + 1) % grad_accu_step == 0:
+            # update origin model weight
+            origin_optimizer.step()
+            origin_optimizer.zero_grad()
+
+            # update sharded model
+            optimizer.step()
+            optimizer.zero_grad()
+
+    # tricky code here, shard the origin model inorder to check the parameters in the same stage.
+    origin_model, origin_optimizer, _, dataloader, _ = booster.boost(
+        origin_model, origin_optimizer, dataloader=dataloader
+    )
+    for p1, p2 in zip(model.unwrap().parameters(), origin_model.unwrap().parameters()):
+        assert_close(p1.to(p2.dtype), p2, atol=1e-2, rtol=1e-2)
+
+
 def run_dist(rank, world_size, port, early_stop: bool = True):
     # init dist env
     colossalai.launch(config=dict(), rank=rank, world_size=world_size, port=port, host="localhost")
     check_3d_plugin(early_stop=early_stop)
+    run_grad_acc_test()
 
 
 @rerun_if_address_is_in_use()