[fix] connector new_block_ids = None 导致 OOM

vllm/distributed/kv_transfer/kv_connector/v1/du/du_swift_connector.py

@@ -48,6 +48,7 @@ class ReqMeta:
         block_ids_tensor = torch.tensor(block_ids)
         num_blocks = block_ids_tensor.shape[0]
         block_offsets = torch.arange(0, block_size)
+        
         slot_mapping = block_offsets.reshape((1, block_size)) + \
                 block_ids_tensor.reshape((num_blocks, 1)) * block_size
         slot_mapping = slot_mapping.flatten()[:valid_num_tokens]
@@ -70,7 +71,7 @@ class DuSwiftConnectorMetadata(KVConnectorMetadata):
         self,
         request_id: str,
         token_ids: list[int],
-        block_ids: list[int],
+        block_ids: list[int],  #这里为None ?? 
         block_size: int,
     ) -> None:
         self.requests.append(
@@ -619,12 +620,15 @@ class DuSwiftConnector(KVConnectorBase_V1):
                 num_scheduled_tokens = (
                     scheduler_output.num_scheduled_tokens)[req_id]
                 num_tokens = (num_scheduled_tokens + num_computed_tokens)
-                # assert req_id in self.chunked_prefill
                 if req_id not in self.chunked_prefill:
                     continue
-                block_ids = new_block_ids[0]
+                delta_block_ids = (
+                    [] if new_block_ids is None else new_block_ids[0])
                 if not resumed_from_preemption:
-                    block_ids = (self.chunked_prefill[req_id][0] + block_ids)
+                    block_ids = (
+                        self.chunked_prefill[req_id][0] + delta_block_ids)
+                else:
+                    block_ids = delta_block_ids
                 prompt_token_ids = self.chunked_prefill[req_id][1]
                 # the request's prompt is chunked prefill again
                 if num_tokens < len(prompt_token_ids):
@@ -644,13 +648,23 @@ class DuSwiftConnector(KVConnectorBase_V1):
             if not resumed_from_preemption:
                 break
             if req_id in self._requests_need_load:
-                request, _ = self._requests_need_load.pop(req_id)
+                request, fallback_block_ids = (
+                    self._requests_need_load.pop(req_id))
                 total_tokens = num_computed_tokens + 1
                 token_ids = request.all_token_ids[:total_tokens]
 
-                # NOTE(rob): For resumed req, new_block_ids is all
-                # of the block_ids for the request.
+                if new_block_ids is not None:
                     block_ids = new_block_ids[0]
+                elif fallback_block_ids:
+                    block_ids = fallback_block_ids
+                    logger.warning(
+                        "Using fallback block_ids for resumed request "
+                        "%s: new_block_ids is None.", req_id)
+                else:
+                    logger.warning(
+                        "Skip KV load meta for resumed request %s: "
+                        "no block_ids available.", req_id)
+                    continue
 
                 meta.add_request(request_id=req_id,
                                  token_ids=token_ids,

vllm/distributed/kv_transfer/kv_connector/v1/p2p/p2p_nccl_connector.py

@@ -477,10 +477,11 @@ class P2pNcclConnector(KVConnectorBase_V1):
         """
         Update KVConnector state after block allocation.
         """
+        #将全量blocks存入字典
         if not self.is_producer and num_external_tokens > 0:
             self._requests_need_load[request.request_id] = (
                 request,
-                blocks.get_block_ids()[0],
+                blocks.get_block_ids()[0],  #转换为block ID 列表  req的全量blocks
             )
 
     def build_connector_meta(
@@ -520,6 +521,7 @@ class P2pNcclConnector(KVConnectorBase_V1):
                     block_size=self._block_size,
                 )
                 continue
+            #新请求
             if new_req.req_id in self._requests_need_load:
                 meta.add_request(
                     request_id=new_req.req_id,
@@ -538,16 +540,19 @@ class P2pNcclConnector(KVConnectorBase_V1):
             if self.is_producer:
                 num_scheduled_tokens = scheduler_output.num_scheduled_tokens[req_id]
                 num_tokens = num_scheduled_tokens + num_computed_tokens
-                # assert req_id in self.chunked_prefill
                 if req_id not in self.chunked_prefill:
                     continue
-                assert new_block_ids is not None
-                block_ids = new_block_ids[0]
+                delta_block_ids = (
+                    [] if new_block_ids is None else new_block_ids[0])
                 if not resumed_from_preemption:
-                    block_ids = self.chunked_prefill[req_id][0] + block_ids
+                    block_ids = (
+                        self.chunked_prefill[req_id][0] + delta_block_ids)
+                else:
+                    block_ids = delta_block_ids
                 prompt_token_ids = self.chunked_prefill[req_id][1]
                 assert prompt_token_ids is not None
                 # the request's prompt is chunked prefill again
+                # ？？？？ 一直累积
                 if num_tokens < len(prompt_token_ids):
                     self.chunked_prefill[req_id] = (block_ids, prompt_token_ids)
                     continue
@@ -563,17 +568,27 @@ class P2pNcclConnector(KVConnectorBase_V1):
 
             # NOTE(rob): here we rely on the resumed requests being
             # the first N requests in the list scheduled_cache_reqs.
+            
             if not resumed_from_preemption:
                 break
             if req_id in self._requests_need_load:
-                request, _ = self._requests_need_load.pop(req_id)
+                request, fallback_block_ids = (
+                    self._requests_need_load.pop(req_id))
                 total_tokens = num_computed_tokens + 1
                 token_ids = request.all_token_ids[:total_tokens]
 
-                # NOTE(rob): For resumed req, new_block_ids is all
-                # of the block_ids for the request.
-                assert new_block_ids is not None
+                if new_block_ids is not None:
                     block_ids = new_block_ids[0]
+                elif fallback_block_ids:
+                    block_ids = fallback_block_ids
+                    logger.warning(
+                        "Using fallback block_ids for resumed request "
+                        "%s: new_block_ids is None.", req_id)
+                else:
+                    logger.warning(
+                        "Skip KV load meta for resumed request %s: "
+                        "no block_ids available.", req_id)
+                    continue
 
                 meta.add_request(
                     request_id=req_id,