[PD] Add different TP sizes support for no-MLA models (#6793)

Co-authored-by: shangmingc <csmthu@gmail.com>
Co-authored-by: Shangming Cai <caishangming@linux.alibaba.com>

python/sglang/srt/disaggregation/base/conn.py

@@ -27,6 +27,8 @@ class KVArgs:
     decode_tp_size: int
     # for pp prefill
     prefill_pp_size: int
+    kv_head_num: int
+    page_size: int
 
 
 class KVPoll:

python/sglang/srt/disaggregation/mooncake/conn.py

@@ -103,6 +103,9 @@ class KVArgsRegisterInfo:
     mooncake_session_id: str
     dst_kv_ptrs: list[int]
     dst_aux_ptrs: list[int]
+    dst_tp_rank: int
+    dst_tp_size: int
+    dst_kv_item_len: int
 
     @classmethod
     def from_zmq(cls, msg: List[bytes]):
@@ -113,6 +116,9 @@ class KVArgsRegisterInfo:
             mooncake_session_id=msg[3].decode("ascii"),
             dst_kv_ptrs=list(struct.unpack(f"{len(msg[4])//8}Q", msg[4])),
             dst_aux_ptrs=list(struct.unpack(f"{len(msg[5])//8}Q", msg[5])),
+            dst_tp_rank=int(msg[6].decode("ascii")),
+            dst_tp_size=int(msg[7].decode("ascii")),
+            dst_kv_item_len=int(msg[8].decode("ascii")),
         )
 
 
@@ -189,6 +195,8 @@ class MooncakeKVManager(BaseKVManager):
             self.session_pool_lock = threading.Lock()
             self.addr_to_rooms_tracker = defaultdict(set)
             self.connection_lock = threading.Lock()
+            self.required_prefill_info_num_map: Dict[int, int] = {}
+            self.decode_kv_arrive_state: Dict[int, Set[int]] = defaultdict(set)
             # Heartbeat interval should be at least 2 seconds
             self.heartbeat_interval = max(
                 float(os.getenv("SGLANG_DISAGGREGATION_HEARTBEAT_INTERVAL", 5.0)), 2.0
@@ -284,6 +292,163 @@ class MooncakeKVManager(BaseKVManager):
 
         return 0
 
+    def send_kvcache_slice(
+        self,
+        mooncake_session_id: str,
+        prefill_kv_indices: npt.NDArray[np.int64],
+        dst_kv_ptrs: list[int],
+        dst_kv_indices: npt.NDArray[np.int64],
+        dst_tp_rank: int,
+        dst_tp_size: int,
+        dst_kv_item_len: int,
+        executor: concurrent.futures.ThreadPoolExecutor,
+    ):
+        """
+        Sends KV cache slices from this Prefill rank to a target Decode rank,
+        supporting generic M-to-N TP size configurations.
+
+        NOTE: This implementation calls the transfer engine for each token slot within
+        each page to ensure correctness for any page_size and head-slicing configuration.
+        This may introduce performance overhead (increased TTFT) for long sequences.
+        """
+        # rank/kv_head config
+        local_tp_rank = self.kv_args.engine_rank
+        local_tp_size = self.tp_size // self.dp_size
+        num_kv_heads = self.kv_args.kv_head_num
+        num_layers = len(self.kv_args.kv_data_ptrs)
+        page_size = self.kv_args.page_size
+
+        heads_per_decode_rank = num_kv_heads * local_tp_size // dst_tp_size
+        heads_per_prefill_rank = num_kv_heads
+        decode_global_head_start = dst_tp_rank * heads_per_decode_rank
+        prefill_global_head_start = local_tp_rank * heads_per_prefill_rank
+        bytes_per_head = dst_kv_item_len // heads_per_decode_rank // page_size
+
+        # decode config
+        decode_rank_item_lens = [dst_kv_item_len for _ in range(num_layers)]
+
+        if local_tp_size > dst_tp_size:
+            src_head_offset = 0
+            num_heads_to_send = heads_per_prefill_rank
+            dst_head_offset = prefill_global_head_start - decode_global_head_start
+        else:
+            src_head_offset = decode_global_head_start - prefill_global_head_start
+            num_heads_to_send = heads_per_decode_rank
+            dst_head_offset = 0
+
+        layer_transfer_params = []
+        for layer_id in range(num_layers):
+            item_len_of_prefill_rank_page = self.kv_args.kv_item_lens[layer_id]
+
+            # Page stride on the target Decode rank for its slice pages
+            item_len_of_decode_rank_page = decode_rank_item_lens[layer_id]
+
+            if item_len_of_prefill_rank_page == 0 or num_kv_heads == 0:
+                logger.error(
+                    f"Invalid item_len_of_prefill_rank_page or num_kv_heads for layer {layer_id}"
+                )
+                return -1
+
+            # Calculate precise byte offset and length for the sub-slice within Prefill page data
+            src_slice_offset = src_head_offset * bytes_per_head
+            dst_slice_offset = dst_head_offset * bytes_per_head
+            slice_lens_per_page = num_heads_to_send * bytes_per_head
+
+            # Sanity check: The data sub-slice we intend to send should fit into D_n's page.
+            # This means slice_lens_per_page <= item_len_of_decode_rank_page
+            if slice_lens_per_page > item_len_of_decode_rank_page:
+                logger.error(
+                    f"[{mooncake_session_id}] Layer {layer_id}: "
+                    f"slice size ({slice_lens_per_page}) exceeds "
+                    f"target page size ({item_len_of_decode_rank_page})"
+                )
+                return -1
+            layer_transfer_params.append(
+                (
+                    self.kv_args.kv_data_ptrs[layer_id],  # Prefill base ptr (all heads)
+                    dst_kv_ptrs[
+                        layer_id
+                    ],  # Decode base ptr (for its slice for this layer)
+                    item_len_of_prefill_rank_page,  # Prefill page size (all heads)2048
+                    item_len_of_decode_rank_page,  # Decode page stride (for its slice page) 1024
+                    src_slice_offset,  # Offset to slice data in Prefill page
+                    dst_slice_offset,  # Offset to slice data in Decode page
+                    slice_lens_per_page,  # Length of slice data per page (actual data to send)
+                )
+            )
+
+        def process_layer_tp_aware(layer_params):
+            (
+                src_ptr,
+                dst_ptr,
+                src_item_len,
+                dst_item_len,
+                src_offset,
+                dst_offset,
+                slice_lens_per_page,
+            ) = layer_params
+            src_addr_list = []
+            dst_addr_list = []
+            length_list = []
+
+            # Calculate strides for a single token slot
+            bytes_per_token_on_prefill = src_item_len // page_size
+            bytes_per_token_on_decode = dst_item_len // page_size
+
+            for i in range(len(prefill_kv_indices)):
+                prefill_page_idx = int(prefill_kv_indices[i])
+                decode_page_idx = int(dst_kv_indices[i])
+
+                # Get the starting memory address for the current source and destination pages
+                src_page_start_addr = src_ptr + prefill_page_idx * src_item_len
+                dst_page_start_addr = dst_ptr + decode_page_idx * dst_item_len
+
+                # Iterate through each valid token slot within the current page
+                for token_slot_in_page in range(page_size):
+                    # Calculate start address of the current token slot
+                    src_token_slot_start_addr = (
+                        src_page_start_addr
+                        + token_slot_in_page * bytes_per_token_on_prefill
+                    )
+                    dst_token_slot_start_addr = (
+                        dst_page_start_addr
+                        + token_slot_in_page * bytes_per_token_on_decode
+                    )
+
+                    # Calculate final source and destination addresses by applying head-slice offsets
+                    src_slice_addr = src_token_slot_start_addr + src_offset
+                    dst_slice_addr = dst_token_slot_start_addr + dst_offset
+
+                    src_addr_list.append(src_slice_addr)
+                    dst_addr_list.append(dst_slice_addr)
+                    length_list.append(slice_lens_per_page)
+                
+                    logger.debug(
+                        f"SYNC: sid={mooncake_session_id}, "
+                        f"src={src_slice_addr}, dst={dst_slice_addr}, len={slice_lens_per_page}"
+                    )
+
+            return self.engine.batch_transfer_sync(
+                mooncake_session_id, src_addr_list, dst_addr_list, length_list
+            )
+
+        futures = [
+            executor.submit(
+                process_layer_tp_aware,
+                layer_params,
+            )
+            for layer_params in layer_transfer_params
+        ]
+
+        for future in concurrent.futures.as_completed(futures):
+            status = future.result()
+            if status != 0:
+                for f in futures:
+                    f.cancel()
+                return status
+
+        return 0
+
     def send_aux(
         self,
         mooncake_session_id: str,
@@ -308,7 +473,7 @@ class MooncakeKVManager(BaseKVManager):
         )
 
     def sync_status_to_decode_endpoint(
-        self, remote: str, dst_port: int, room: int, status: int
+        self, remote: str, dst_port: int, room: int, status: int, prefill_rank: int
     ):
         if ":" in remote:
             remote = remote.split(":")[0]
@@ -316,6 +481,7 @@ class MooncakeKVManager(BaseKVManager):
             [
                 str(room).encode("ascii"),
                 str(status).encode("ascii"),
+                str(prefill_rank).encode("ascii"),
             ]
         )
 
@@ -332,6 +498,7 @@ class MooncakeKVManager(BaseKVManager):
                 )
                 polls = []
                 dst_ranks_infos = []
+                local_rank = self.kv_args.engine_rank
                 for req in reqs_to_be_processed:
                     if not req.is_dummy:
                         # Early exit if the request has failed
@@ -347,6 +514,7 @@ class MooncakeKVManager(BaseKVManager):
                                     req.dst_port,
                                     req.room,
                                     KVPoll.Failed,
+                                    local_rank,
                                 )
                                 break
 
@@ -364,15 +532,31 @@ class MooncakeKVManager(BaseKVManager):
                                 f"len(chunked_dst_kv_indice) = {len(chunked_dst_kv_indice)}, len(kv_chunk.prefill_kv_indices) = {len(kv_chunk.prefill_kv_indices)}"
                             )
 
+                        target_rank_registration_info: KVArgsRegisterInfo = (
+                            self.decode_kv_args_table[req.mooncake_session_id]
+                        )
+                        local_tp_size = self.tp_size // self.dp_size
+                        if self.is_mla_backend or (
+                            local_tp_size == target_rank_registration_info.dst_tp_size
+                        ):
                             ret = self.send_kvcache(
                                 req.mooncake_session_id,
                                 kv_chunk.prefill_kv_indices,
-                            self.decode_kv_args_table[
-                                req.mooncake_session_id
-                            ].dst_kv_ptrs,
+                                target_rank_registration_info.dst_kv_ptrs,
                                 chunked_dst_kv_indice,
                                 executor,
                             )
+                        else:
+                            ret = self.send_kvcache_slice(
+                                req.mooncake_session_id,
+                                kv_chunk.prefill_kv_indices,
+                                target_rank_registration_info.dst_kv_ptrs,
+                                chunked_dst_kv_indice,
+                                target_rank_registration_info.dst_tp_rank,
+                                target_rank_registration_info.dst_tp_size,
+                                target_rank_registration_info.dst_kv_item_len,
+                                executor,
+                            )
                         if ret != 0:
                             with self.session_lock:
                                 self.session_failures[req.mooncake_session_id] += 1
@@ -388,7 +572,11 @@ class MooncakeKVManager(BaseKVManager):
                             )
                             self.update_status(kv_chunk.room, KVPoll.Failed)
                             self.sync_status_to_decode_endpoint(
-                                req.endpoint, req.dst_port, req.room, KVPoll.Failed
+                                req.endpoint,
+                                req.dst_port,
+                                req.room,
+                                KVPoll.Failed,
+                                local_rank,
                             )
                             break
 
@@ -413,7 +601,7 @@ class MooncakeKVManager(BaseKVManager):
                                 self.update_status(req.room, status)
                                 for endpoint, dst_port, room in dst_ranks_infos:
                                     self.sync_status_to_decode_endpoint(
-                                        endpoint, dst_port, room, status
+                                        endpoint, dst_port, room, status, local_rank
                                     )
                     else:
                         # Dummy request means the decode instance is not used, so its status can be marked as success directly
@@ -479,10 +667,28 @@ class MooncakeKVManager(BaseKVManager):
 
         def decode_thread():
             while True:
-                (bootstrap_room, status) = self.server_socket.recv_multipart()
+                (bootstrap_room, status, prefill_rank) = (
+                    self.server_socket.recv_multipart()
+                )
                 status = int(status.decode("ascii"))
                 bootstrap_room = int(bootstrap_room.decode("ascii"))
-                if status == KVPoll.Failed:
+                prefill_rank = int(prefill_rank.decode("ascii"))
+
+                if status == KVPoll.Success:
+                    # record arrived prefill_rank
+                    self.decode_kv_arrive_state[bootstrap_room].add(prefill_rank)
+                    expected_prefill_num = self.required_prefill_info_num_map[
+                        bootstrap_room
+                    ]
+                    arrived_prefill_num = len(
+                        self.decode_kv_arrive_state[bootstrap_room]
+                    )
+                    if (
+                        self.is_mla_backend
+                        or arrived_prefill_num == expected_prefill_num
+                    ):
+                        self.update_status(bootstrap_room, KVPoll.Success)
+                elif status == KVPoll.Failed:
                     self.record_failure(
                         bootstrap_room,
                         f"Failed to get kvcache from prefill instance, it might be dead",
@@ -713,7 +919,10 @@ class MooncakeKVSender(BaseKVSender):
 
         if not is_last:
             self.kv_mgr.add_transfer_request(
-                self.bootstrap_room, kv_indices, index_slice, False
+                self.bootstrap_room,
+                kv_indices,
+                index_slice,
+                False,
             )
         else:
             self.kv_mgr.add_transfer_request(
@@ -822,23 +1031,26 @@ class MooncakeKVReceiver(BaseKVReceiver):
                 self.kv_mgr.kv_args.engine_rank % local_tp_size_per_dp_rank
             )
             self.required_dst_info_num = 1
+            self.required_prefill_info_num = 1
             self.target_tp_ranks = [self.target_tp_rank]
         elif local_tp_size_per_dp_rank > prefill_tp_size_per_dp_rank:
-            assert (
-                self.kv_mgr.is_mla_backend
-            ), "PD with different TP sizes per DP rank is not yet supported for non-MLA models"
+            if not self.kv_mgr.is_mla_backend:
+                logger.warning_once(
+                    "Performance is NOT guaranteed when using different TP sizes for non-MLA models. "
+                )
             self.target_tp_rank = (
                 self.kv_mgr.kv_args.engine_rank % local_tp_size_per_dp_rank
             ) // (local_tp_size_per_dp_rank // prefill_tp_size_per_dp_rank)
             self.required_dst_info_num = (
                 local_tp_size_per_dp_rank // prefill_tp_size_per_dp_rank
             )
+            self.required_prefill_info_num = 1
             self.target_tp_ranks = [self.target_tp_rank]
         else:
-            assert (
-                self.kv_mgr.is_mla_backend
-            ), "PD with different TP sizes per DP rank is not yet supported for non-MLA models"
-
+            if not self.kv_mgr.is_mla_backend:
+                logger.warning_once(
+                    "Performance is NOT guaranteed when using different TP sizes for non-MLA models. "
+                )
             # For non-MLA models, one decode rank needs to retrieve KVCache from multiple prefill ranks for non MLA models;
             self.target_tp_ranks = [
                 rank
@@ -855,6 +1067,9 @@ class MooncakeKVReceiver(BaseKVReceiver):
             # or the KVPoll will never be set correctly
             self.target_tp_rank = self.target_tp_ranks[0]
             self.required_dst_info_num = 1
+            self.required_prefill_info_num = (
+                prefill_tp_size_per_dp_rank // local_tp_size_per_dp_rank
+            )
 
         if self.data_parallel_rank is not None:
             logger.debug(f"Targeting DP rank: {self.data_parallel_rank}")
@@ -862,6 +1077,9 @@ class MooncakeKVReceiver(BaseKVReceiver):
         else:
             self.target_dp_group = bootstrap_room % self.prefill_dp_size
 
+        self.kv_mgr.required_prefill_info_num_map[self.bootstrap_room] = (
+            self.required_prefill_info_num
+        )
         # NOTE: key distinguished by bootstrap_addr, target_dp_group, and target_tp_rank
         bootstrap_key = (
             f"{self.bootstrap_addr}_{self.target_dp_group}_{self.target_tp_rank}"
@@ -875,11 +1093,15 @@ class MooncakeKVReceiver(BaseKVReceiver):
                     self.target_dp_group,
                 )
                 if bootstrap_info is not None:
-                    # NOTE: only support MLA for now: select one prefill rank as real rank
+                    if self.kv_mgr.is_mla_backend:
+                        # MLA :select one prefill rank as real rank
                         bootstrap_info["is_dummy"] = not bool(
                             target_tp_rank == self.target_tp_rank
                             or self.target_tp_rank is None
                         )
+                    else:
+                        # no-MLA：select all prefill ranks
+                        bootstrap_info["is_dummy"] = False
                     logger.debug(
                         f"Fetched bootstrap info: {bootstrap_info} for DP {self.target_dp_group} TP {target_tp_rank}"
                     )
@@ -951,6 +1173,12 @@ class MooncakeKVReceiver(BaseKVReceiver):
             packed_aux_data_ptrs = b"".join(
                 struct.pack("Q", ptr) for ptr in self.kv_mgr.kv_args.aux_data_ptrs
             )
+            tp_rank = self.kv_mgr.kv_args.engine_rank
+            tp_size = self.kv_mgr.tp_size // self.kv_mgr.dp_size
+            kv_item_len = self.kv_mgr.kv_args.kv_item_lens[0]
+            dst_tp_rank = str(tp_rank).encode("ascii")
+            dst_tp_size = str(tp_size).encode("ascii")
+            dst_kv_item_len = str(kv_item_len).encode("ascii")
 
             sock, lock = self._connect("tcp://" + self.prefill_server_url)
             with lock:
@@ -962,6 +1190,9 @@ class MooncakeKVReceiver(BaseKVReceiver):
                         self.session_id.encode("ascii"),
                         packed_kv_data_ptrs,
                         packed_aux_data_ptrs,
+                        dst_tp_rank,
+                        dst_tp_size,
+                        dst_kv_item_len,
                     ]
                 )
 
@@ -1009,6 +1240,8 @@ class MooncakeKVReceiver(BaseKVReceiver):
     def clear(self) -> None:
         if self.bootstrap_room in self.kv_mgr.request_status:
             self.kv_mgr.request_status.pop(self.bootstrap_room)
+            self.kv_mgr.required_prefill_info_num_map.pop(self.bootstrap_room)
+            self.kv_mgr.decode_kv_arrive_state.pop(self.bootstrap_room)
 
     def failure_exception(self):
         # Explicitly set the status to failure since this request has failed in another rank

python/sglang/srt/disaggregation/prefill.py

@@ -122,6 +122,9 @@ class PrefillBootstrapQueue:
         kv_args.kv_data_ptrs = kv_data_ptrs
         kv_args.kv_data_lens = kv_data_lens
         kv_args.kv_item_lens = kv_item_lens
+        if not self.is_mla_backend:
+            kv_args.kv_head_num = self.token_to_kv_pool.head_num
+        kv_args.page_size = self.token_to_kv_pool.page_size
 
         kv_args.aux_data_ptrs, kv_args.aux_data_lens, kv_args.aux_item_lens = (
             self.metadata_buffers.get_buf_infos()