Fix distribute offload bug.

Fix distribute offload bug.

lightx2v/models/networks/wan/audio_adapter.py

@@ -157,8 +157,8 @@ class PerceiverAttentionCA(nn.Module):
             v=v,
             cu_seqlens_q=torch.cat([q_lens.new_zeros([1]), q_lens]).cumsum(0, dtype=torch.int32).to(q.device, non_blocking=True),
             cu_seqlens_k=torch.cat([k_lens.new_zeros([1]), k_lens]).cumsum(0, dtype=torch.int32).to(q.device, non_blocking=True),
-            max_seqlen_q=q_lens.max(),
-            max_seqlen_k=k_lens.max(),
+            max_seqlen_q=q_lens.max().item(),
+            max_seqlen_k=k_lens.max().item(),
             dropout_p=0.0,
             softmax_scale=None,
             causal=False,

lightx2v/models/networks/wan/model.py

@@ -215,7 +215,7 @@ class WanModel:
                         weight_dict = self._load_quant_split_ckpt(unified_dtype, sensitive_layer)
 
             if self.config.get("device_mesh") is not None:
-                weight_dict = self._distribute_weights_multi_gpu(weight_dict, is_weight_loader)
+                weight_dict = self._load_weights_distribute(weight_dict, is_weight_loader)
 
             self.original_weight_dict = weight_dict
         else:
@@ -234,49 +234,62 @@ class WanModel:
         del self.original_weight_dict
         torch.cuda.empty_cache()
 
-    def _distribute_weights_multi_gpu(self, weight_dict, is_weight_loader):
-        """Distribute weights across multiple GPUs or CPUs based on offload config."""
+    def _load_weights_distribute(self, weight_dict, is_weight_loader):
         global_src_rank = 0
-
-        # Determine target device for distribution
         target_device = "cpu" if self.cpu_offload else "cuda"
 
         if is_weight_loader:
-            # Create metadata for broadcasting
             meta_dict = {}
             for key, tensor in weight_dict.items():
                 meta_dict[key] = {"shape": tensor.shape, "dtype": tensor.dtype}
 
-            # Broadcast metadata to all ranks
             obj_list = [meta_dict]
             dist.broadcast_object_list(obj_list, src=global_src_rank)
             synced_meta_dict = obj_list[0]
         else:
-            # Non-loader ranks receive metadata
             obj_list = [None]
             dist.broadcast_object_list(obj_list, src=global_src_rank)
             synced_meta_dict = obj_list[0]
 
-        # Create empty tensors on target device for all ranks
         distributed_weight_dict = {}
         for key, meta in synced_meta_dict.items():
             distributed_weight_dict[key] = torch.empty(meta["shape"], dtype=meta["dtype"], device=target_device)
 
-        # Synchronize before broadcasting
         if target_device == "cuda":
             dist.barrier(device_ids=[torch.cuda.current_device()])
         else:
             dist.barrier()
 
-        # Broadcast weights from rank 0 to all ranks
         for key in sorted(synced_meta_dict.keys()):
             if is_weight_loader:
-                # Copy weights to broadcast tensor
                 distributed_weight_dict[key].copy_(weight_dict[key], non_blocking=True)
 
-            # Broadcast to all ranks
+            if target_device == "cpu":
+                if is_weight_loader:
+                    gpu_tensor = distributed_weight_dict[key].cuda()
+                    dist.broadcast(gpu_tensor, src=global_src_rank)
+                    distributed_weight_dict[key].copy_(gpu_tensor.cpu(), non_blocking=True)
+                    del gpu_tensor
+                    torch.cuda.empty_cache()
+                else:
+                    gpu_tensor = torch.empty_like(distributed_weight_dict[key], device="cuda")
+                    dist.broadcast(gpu_tensor, src=global_src_rank)
+                    distributed_weight_dict[key].copy_(gpu_tensor.cpu(), non_blocking=True)
+                    del gpu_tensor
+                    torch.cuda.empty_cache()
+
+                if distributed_weight_dict[key].is_pinned():
+                    distributed_weight_dict[key].copy_(distributed_weight_dict[key], non_blocking=True)
+            else:
                 dist.broadcast(distributed_weight_dict[key], src=global_src_rank)
 
+        if target_device == "cuda":
+            torch.cuda.synchronize()
+        else:
+            for tensor in distributed_weight_dict.values():
+                if tensor.is_pinned():
+                    tensor.copy_(tensor, non_blocking=False)
+
         logger.info(f"Weights distributed across {dist.get_world_size()} devices on {target_device}")
         return distributed_weight_dict
 

lightx2v/utils/utils.py

@@ -360,12 +360,10 @@ def load_weights(checkpoint_path, cpu_offload=False, remove_key=None):
     synced_meta_dict = obj_list[0]
 
     if cpu_offload:
-        # Multi-GPU + offload: weights on CPU
         target_device = "cpu"
         distributed_weight_dict = {key: torch.empty(meta["shape"], dtype=meta["dtype"], device=target_device) for key, meta in synced_meta_dict.items()}
         dist.barrier()
     else:
-        # Multi-GPU + non-offload: weights on GPU
         target_device = torch.device(f"cuda:{current_rank}")
         distributed_weight_dict = {key: torch.empty(meta["shape"], dtype=meta["dtype"], device=target_device) for key, meta in synced_meta_dict.items()}
         dist.barrier(device_ids=[torch.cuda.current_device()])
@@ -374,11 +372,29 @@ def load_weights(checkpoint_path, cpu_offload=False, remove_key=None):
         tensor_to_broadcast = distributed_weight_dict[key]
         if is_weight_loader:
             tensor_to_broadcast.copy_(cpu_weight_dict[key], non_blocking=True)
+
+        if cpu_offload:
+            if is_weight_loader:
+                gpu_tensor = tensor_to_broadcast.cuda()
+                dist.broadcast(gpu_tensor, src=src_global_rank)
+                tensor_to_broadcast.copy_(gpu_tensor.cpu(), non_blocking=True)
+                del gpu_tensor
+                torch.cuda.empty_cache()
+            else:
+                gpu_tensor = torch.empty_like(tensor_to_broadcast, device="cuda")
+                dist.broadcast(gpu_tensor, src=src_global_rank)
+                tensor_to_broadcast.copy_(gpu_tensor.cpu(), non_blocking=True)
+                del gpu_tensor
+                torch.cuda.empty_cache()
+        else:
             dist.broadcast(tensor_to_broadcast, src=src_global_rank)
 
     if is_weight_loader:
         del cpu_weight_dict
 
+    if cpu_offload:
+        torch.cuda.empty_cache()
+
     logger.info(f"Weights distributed across {dist.get_world_size()} devices on {target_device}")
     return distributed_weight_dict
 
@@ -388,7 +404,6 @@ def masks_like(tensor, zero=False, generator=None, p=0.2):
     out = torch.ones_like(tensor)
     if zero:
         if generator is not None:
-            # 生成随机数判断是否需要修改
             random_num = torch.rand(1, generator=generator, device=generator.device).item()
             if random_num < p:
                 out[:, 0] = torch.zeros_like(out[:, 0])