Merge pull request #4176 from ver217/feature/pipeline-policy

[pipeline] fit shardformer policy

colossalai/shardformer/policies/auto_policy.py

@@ -3,7 +3,7 @@ from dataclasses import dataclass
 
 import torch.nn as nn
 
-from .basepolicy import Policy
+from .base_policy import Policy
 
 __all__ = ["PolicyLocation", "get_autopolicy", "import_policy"]
 

colossalai/shardformer/policies/base_policy.py

@@ -2,9 +2,13 @@
 
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
-from typing import Any, Callable, Dict, List, Type, Union
+from typing import Any, Callable, Dict, List, Optional, Union
 
 import torch.nn as nn
+from torch import Tensor
+from torch.nn import Module
+
+from colossalai.pipeline.stage_manager import PipelineStageManager
 
 from ..shard.shard_config import ShardConfig
 
@@ -71,9 +75,8 @@ class Policy(ABC):
     """
 
     def __init__(self) -> None:
-        self.shard_config = None
-        self.model = None
-        self.shard_config = None
+        self.shard_config: Optional[ShardConfig] = None
+        self.model: Optional[Module] = None
 
     def set_model(self, model: nn.Module) -> None:
         r"""
@@ -94,6 +97,12 @@ class Policy(ABC):
         self.shard_config = shard_config
         self.config_sanity_check()
 
+    @property
+    def pipeline_stage_manager(self) -> Optional[PipelineStageManager]:
+        if self.shard_config is not None:
+            return self.shard_config.pipeline_stage_manager
+        return None
+
     @abstractmethod
     def config_sanity_check(self):
         """
@@ -151,3 +160,19 @@ class Policy(ABC):
             policy[target_key] = ModulePolicyDescription(sub_module_replacement=description)
 
         return policy
+
+    def get_held_layers(self) -> List[Module]:
+        """Get layers that should be held in current stage. This method should be implemented by subclass.
+
+        Returns:
+            List[Module]: List of layers that should be hold in current stage
+        """
+        raise NotImplementedError
+
+    def get_shared_params(self) -> List[Dict[int, Tensor]]:
+        """Get parameters that should be shared across stages. This method should be implemented by subclass.
+
+        Returns:
+            List[Dict[int, Tensor]]: List of parameters that should be shared across stages. E.g. [{0: module.model.embed_tokens.weight, 3: module.lm_head.weight}]
+        """
+        return []

colossalai/shardformer/policies/bert.py

@@ -3,7 +3,7 @@ import torch.nn as nn
 import colossalai.shardformer.layer as col_nn
 
 from .._utils import getattr_, setattr_
-from .basepolicy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
+from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
 
 __all__ = [
     'BertPolicy', 'BertModelPolicy', 'BertForPretrainingPolicy', 'BertLMHeadModelPolicy', 'BertForMaskedLMPolicy',

colossalai/shardformer/policies/bloom.py

@@ -4,7 +4,7 @@ import colossalai.shardformer.layer as col_nn
 
 from .._utils import getattr_, setattr_
 from ..modeling.bloom import build_bloom_alibi_tensor_fn
-from .basepolicy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
+from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
 
 
 class BloomPolicy(Policy):

colossalai/shardformer/policies/gpt2.py

@@ -3,7 +3,7 @@ import torch.nn as nn
 import colossalai.shardformer.layer as col_nn
 
 from .._utils import getattr_, setattr_
-from .basepolicy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
+from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
 
 __all__ = [
     'GPT2Policy', 'GPT2ModelPolicy', 'GPT2LMHeadModelPolicy', 'GPT2DoubleHeadsModelPolicy',

colossalai/shardformer/policies/llama.py

@@ -4,7 +4,7 @@ import torch.nn as nn
 
 from colossalai.shardformer.layer import FusedRMSNorm, Linear1D_Col, Linear1D_Row, VocabParallelEmbedding1D
 
-from .basepolicy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
+from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
 
 __all__ = ['LlamaPolicy', 'LlamaForCausalLMPolicy', 'LlamaForSequenceClassificationPolicy']
 

colossalai/shardformer/policies/opt.py

@@ -1,7 +1,7 @@
 from colossalai.shardformer.layer import FusedLayerNorm, Linear1D_Col, Linear1D_Row, VocabParallelEmbedding1D
 
 from .._utils import getattr_, setattr_
-from .basepolicy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
+from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
 
 __all__ = [
     'OPTPolicy', 'OPTModelPolicy', 'OPTForCausalLMPolicy', 'OPTForSequenceClassificationPolicy',

colossalai/shardformer/policies/t5.py

@@ -6,10 +6,10 @@ from colossalai.shardformer.layer import (
     Linear1D_Row,
     VocabParallelEmbedding1D,
 )
-from colossalai.shardformer.policies.basepolicy import ModulePolicyDescription
+from colossalai.shardformer.policies.base_policy import ModulePolicyDescription
 
 from .._utils import getattr_, setattr_
-from .basepolicy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
+from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
 
 __all__ = ["T5ModelPolicy", "T5ForConditionalGenerationPolicy", "T5EncoderPolicy"]
 

colossalai/shardformer/policies/vit.py

@@ -4,7 +4,7 @@ import torch.nn as nn
 
 from colossalai.shardformer.layer import DropoutForReplicatedInput, FusedLayerNorm, Linear1D_Col, Linear1D_Row
 
-from .basepolicy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
+from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
 
 __all__ = ['ViTPolicy']
 

colossalai/shardformer/shard/shard_config.py

@@ -1,8 +1,11 @@
 from dataclasses import dataclass
+from typing import Optional
 
 import torch.distributed as dist
 from torch.distributed import ProcessGroup
 
+from colossalai.pipeline.stage_manager import PipelineStageManager
+
 __all__ = ['ShardConfig']
 
 
@@ -12,12 +15,14 @@ class ShardConfig:
     The config for sharding the huggingface model
 
     Args:
-        tensor_parallel_process_group (int): The process group for tensor parallelism, defaults to None, which is the global process group.
+        tensor_parallel_process_group (Optional[ProcessGroup]): The process group for tensor parallelism, defaults to None, which is the global process group.
+        pipeline_stage_manager (Optional[PipelineStageManager]): The pipeline stage manager, defaults to None, which means no pipeline.
         enable_tensor_parallelism (bool): Whether to turn on tensor parallelism, default is True.
         enable_fused_normalization (bool): Whether to use fused layernorm, default is False.
         enable_all_optimization (bool): Whether to turn on all optimization, default is False.
     """
-    tensor_parallel_process_group: ProcessGroup = None
+    tensor_parallel_process_group: Optional[ProcessGroup] = None
+    pipeline_stage_manager: Optional[PipelineStageManager] = None
     enable_tensor_parallelism: bool = True
     enable_fused_normalization: bool = False
     enable_all_optimization: bool = False

colossalai/shardformer/shard/sharder.py

@@ -1,11 +1,15 @@
 from typing import Any, Callable, Dict, List, Union
 
 import torch.nn as nn
+from torch import Tensor
+
+from colossalai.lazy import LazyTensor
 
 from .._utils import getattr_, setattr_
-from ..policies.autopolicy import get_autopolicy
-from ..policies.basepolicy import Policy, SubModuleReplacementDescription
+from ..policies.auto_policy import get_autopolicy
+from ..policies.base_policy import Policy, SubModuleReplacementDescription
 from .shard_config import ShardConfig
+from .utils import set_tensors_to_none
 
 __all__ = ['ModelSharder', 'shard_model']
 
@@ -25,15 +29,18 @@ class ModelSharder(object):
         self.policy = get_autopolicy(self.model) if policy is None else policy
         self.shard_config = shard_config
 
-    def shard(self) -> None:
+    def shard(self) -> List[Dict[int, Tensor]]:
         r"""
         Shard the model according to the policy
         """
         self.policy.set_model(self.model)
         self.policy.set_shard_config(self.shard_config)
         self._preprocess()
+        self._release_unheld_layers()
         self._replace_module()
+        self._materialize()
         self._postprocess()
+        return self.policy.get_shared_params()
 
     def _preprocess(self) -> None:
         self.model = self.policy.preprocess()
@@ -172,3 +179,23 @@ class ModelSharder(object):
                 )
 
             setattr_(org_layer, suffix, replace_layer)
+
+    def _release_unheld_layers(self) -> None:
+        r"""
+        Release the unheld layers in the model
+        """
+        if self.shard_config and self.shard_config.pipeline_stage_manager:
+            held_layers = self.policy.get_held_layers()
+            set_tensors_to_none(self.model, exclude=set(held_layers))
+
+    def _materialize(self) -> None:
+        r"""
+        Materialize the model if lazy initialization is used
+        """
+        for p in self.model.parameters():
+            if isinstance(p, LazyTensor):
+                p.materialize()
+
+        for b in self.model.buffers():
+            if isinstance(b, LazyTensor):
+                b.materialize()

colossalai/shardformer/shard/shardformer.py

@@ -1,8 +1,11 @@
+from typing import Dict, List, Tuple
+
 import torch.nn as nn
+from torch import Tensor
 
 from colossalai.cluster import DistCoordinator
 
-from ..policies.basepolicy import Policy
+from ..policies.base_policy import Policy
 from .shard_config import ShardConfig
 from .sharder import ModelSharder
 
@@ -24,7 +27,7 @@ class ShardFormer:
     org_model = BertForMaskedLM.from_pretrained('bert-base-uncased')
     shard_config = ShardConfig()
     shard_former = ShardFormer(shard_config=shard_config)
-    model = shard_former.optimize(org_model)
+    model, shared_params = shard_former.optimize(org_model)
     ```
     """
 
@@ -32,7 +35,7 @@ class ShardFormer:
         self.coordinator = DistCoordinator()
         self.shard_config = shard_config
 
-    def optimize(self, model: nn.Module, policy: Policy = None):
+    def optimize(self, model: nn.Module, policy: Policy = None) -> Tuple[nn.Module, List[Dict[int, Tensor]]]:
         r"""
         This method will optimize the model based on the given policy.
 
@@ -40,7 +43,9 @@ class ShardFormer:
             model (`torch.nn.Model`): the origin huggingface model
             shard_config (`ShardConfig`): the config for distribute information
             policy (`Policy`): the custom policy for sharding
+
+        Returns: the sharded model and the shared parameters
         """
         sharder = ModelSharder(model=model, shard_config=self.shard_config, policy=policy)
-        sharder.shard()
-        return model
+        shared_params = sharder.shard()
+        return model, shared_params

colossalai/shardformer/shard/utils.py

@@ -0,0 +1,19 @@
+from typing import Set
+
+import torch.nn as nn
+
+
+def set_tensors_to_none(model: nn.Module, exclude: Set[nn.Module] = set()) -> None:
+    """Set all parameters and buffers of model to None
+
+    Args:
+        model (nn.Module): The model to set
+    """
+    if model in exclude:
+        return
+    for child in model.children():
+        set_tensors_to_none(child, exclude=exclude)
+    for n, p in model.named_parameters(recurse=False):
+        setattr(model, n, None)
+    for n, buf in model.named_buffers(recurse=False):
+        setattr(model, n, None)

tests/test_shardformer/test_model/_utils.py

@@ -12,8 +12,8 @@ def build_model(model_fn, enable_fused_normalization=True, enable_tensor_paralle
                                enable_tensor_parallelism=enable_tensor_parallelism)
     model_copy = copy.deepcopy(org_model)
     shard_former = ShardFormer(shard_config=shard_config)
-    sharded_model = shard_former.optimize(model_copy).cuda()
-    return org_model, sharded_model
+    sharded_model, shared_params = shard_former.optimize(model_copy)
+    return org_model, sharded_model.cuda()
 
 
 def run_forward(original_model, sharded_model, data_gen_fn, output_transform_fn, loss_fn):

tests/test_shardformer/test_shard_utils.py

@@ -0,0 +1,27 @@
+import torch
+import torch.nn as nn
+
+from colossalai.shardformer.shard.utils import set_tensors_to_none
+
+
+class Net(nn.Module):
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.layers = nn.Sequential(nn.Linear(1, 2), nn.Linear(2, 3))
+        self.out = nn.Linear(3, 1)
+
+
+def test_release_layer():
+    orig_cuda_allocated = torch.cuda.memory_allocated()
+    model = Net().cuda()
+    set_tensors_to_none(model, exclude={model.layers[0]})
+    assert model.layers[1].weight is None
+    assert model.layers[1].bias is None
+    assert model.out.weight is None
+    assert model.out.bias is None
+    set_tensors_to_none(model)
+    assert model.layers[0].weight is None
+    assert model.layers[0].bias is None
+    assert len(list(model.parameters())) == 0
+    assert torch.cuda.memory_allocated() == orig_cuda_allocated

tests/test_shardformer/test_with_torch_ddp.py

@@ -44,7 +44,7 @@ def check_shardformer_with_ddp(rank, world_size, port):
     for name, (model_fn, data_gen_fn, output_transform_fn, loss_fn, _) in sub_model_zoo.items():
         # create and shard model
         model = model_fn().cuda()
-        sharded_model = shardformer.optimize(model)
+        sharded_model, _ = shardformer.optimize(model)
 
         # add ddp
         sharded_ddp_model = DDP(sharded_model, process_group=dp_process_group)