[gemini] collect cpu-gpu moving volume in each iteration (#813)

colossalai/gemini/stateful_tensor_mgr.py

@@ -28,6 +28,8 @@ class StatefulTensorMgr(object):
         self._compute_list: List[StatefulTensor] = []
         self._compute_idx: int = -1
 
+        self._cpu_gpu_move_volume = 0
+
     def register_stateful_param(self, param: ShardedParamV2) -> None:
         assert isinstance(param, ShardedParamV2)
         for t in param.get_payload_tensors():
@@ -56,20 +58,26 @@ class StatefulTensorMgr(object):
                     cuda_demand += colo_tensor_mem_usage(tensor.payload)[1]
             else:
                 raise RuntimeError
-        self._tensor_placement_policy.evict_tensors(hold_cuda_tensor_list,
+        self._cpu_gpu_move_volume += self._tensor_placement_policy.evict_tensors(hold_cuda_tensor_list,
-                                                    cuda_demand=cuda_demand,
+                                                                                 cuda_demand=cuda_demand,
-                                                    warmup=self._warmup,
+                                                                                 warmup=self._warmup,
-                                                    compute_list=self._compute_list,
+                                                                                 compute_list=self._compute_list,
-                                                    compute_idx=self._compute_idx)
+                                                                                 compute_idx=self._compute_idx)
         # move COMPUTE tensors to CUDA
         for t in move_to_cuda_tensor_list:
             colo_model_data_tensor_move_inline(t, get_current_device())
+            self._cpu_gpu_move_volume += t.payload.numel() * t.payload.element_size()
+
+    @property
+    def cpu_gpu_move_volume(self):
+        return self._cpu_gpu_move_volume
 
     def reset(self):
         """This function must be called when each iteration finishes
         """
         self._warmup = False
         self._compute_idx = -1
+        self._cpu_gpu_move_volume = 0
 
     def _trans_state(self, trans_state_func, stateful_tensor, state):
         trans_state_func(state)

colossalai/gemini/tensor_placement_policy.py

@@ -27,9 +27,12 @@ class CPUTensorPlacementPolicy(TensorPlacementPolicy):
     def __init__(self, mem_stats_collector: Optional[MemStatsCollector] = None) -> None:
         super().__init__(torch.device('cpu'), mem_stats_collector=mem_stats_collector)
 
-    def evict_tensors(self, hold_cuda_tensor_list: List[StatefulTensor], **kwargs) -> None:
+    def evict_tensors(self, hold_cuda_tensor_list: List[StatefulTensor], **kwargs) -> int:
+        volume = 0
         for t in hold_cuda_tensor_list:
             colo_model_data_tensor_move_inline(t, self.device)
+            volume += t.payload.numel() * t.payload.element_size()
+        return volume
 
 
 class CUDATensorPlacementPolicy(TensorPlacementPolicy):
@@ -38,8 +41,8 @@ class CUDATensorPlacementPolicy(TensorPlacementPolicy):
         assert torch.cuda.is_available(), 'Cannot use CUDATensorPlacementPolicy when CUDA is not available'
         super().__init__(get_current_device(), mem_stats_collector=mem_stats_collector)
 
-    def evict_tensors(self, hold_cuda_tensor_list: List[StatefulTensor], **kwargs) -> None:
+    def evict_tensors(self, hold_cuda_tensor_list: List[StatefulTensor], **kwargs) -> int:
-        pass
+        return 0
 
 
 class AutoTensorPlacementPolicy(TensorPlacementPolicy):
@@ -57,7 +60,24 @@ class AutoTensorPlacementPolicy(TensorPlacementPolicy):
                       warmup: bool = True,
                       compute_list: List[StatefulTensor] = [],
                       compute_idx: int = 0,
-                      **kwargs) -> None:
+                      **kwargs) -> int:
+        """
+        Evict tensors from CUDA device.
+
+        Args:
+            hold_cuda_tensor_list (List[StatefulTensor]): the list of tensor in state of HOLD-like
+            cuda_demand (int, optional): the volume of data needed on cuda device. Defaults to 0.
+            warmup (bool, optional): a flag indicates whether in the phase of warmup. Defaults to True.
+            compute_list (List[StatefulTensor], optional): TODO. Defaults to [].
+            compute_idx (int, optional): the idx of computing device. Defaults to 0.
+
+        Raises:
+            RuntimeError:
+
+        Returns:
+            int: the volume of memory that is evicted
+        """
+        volume = 0
         cuda_capacity = colo_device_memory_capacity(get_current_device())
         used_cuda_model_data = GLOBAL_MODEL_DATA_TRACER.cuda_usage
         if warmup:
@@ -87,11 +107,14 @@ class AutoTensorPlacementPolicy(TensorPlacementPolicy):
                     break
                 freed_cuda_model_data += colo_tensor_mem_usage(t)[0]
                 colo_model_data_tensor_move_inline(t, torch.device('cpu'))
+                volume += t.payload.numel() * t.payload.element_size()
             if freed_cuda_model_data < to_free_cuda_model_data:
                 raise RuntimeError(
                     f"Adjust layout failed! No enough CUDA memory! Need {to_free_cuda_model_data}, freed {freed_cuda_model_data}"
                 )
 
+        return volume
+
 
 class TensorPlacementPolicyFactory:
 

colossalai/zero/utils/zero_hook.py

@@ -2,6 +2,7 @@ from typing import Optional
 
 import torch
 import torch.distributed as dist
+from colossalai.logging import get_dist_logger
 from colossalai.registry import OPHOOKS
 
 from colossalai.utils import get_current_device
@@ -27,6 +28,7 @@ class ZeroHook(BaseOpHook):
                  stateful_tensor_mgr: Optional[StatefulTensorMgr] = None,
                  process_group: Optional[dist.ProcessGroup] = None):
         super().__init__()
+        self.logger = get_dist_logger("ZeROHook")
         self.shard_strategy = shard_strategy
         self.process_group = process_group
 
@@ -112,4 +114,6 @@ class ZeroHook(BaseOpHook):
 
     def post_iter(self):
         if self._stateful_tensor_mgr:
+            self.logger.info(
+                f"CPU-GPU data moving this iteration {self._stateful_tensor_mgr.cpu_gpu_move_volume/1e9} GB", ranks=[0])
             self._stateful_tensor_mgr.reset()