Support colocating requests (#7973)

python/sglang/srt/managers/data_parallel_controller.py

@@ -26,6 +26,7 @@ import zmq
 
 from sglang.srt.layers.dp_attention import compute_dp_attention_world_info
 from sglang.srt.managers.io_struct import (
+    BlockReqInput,
     TokenizedEmbeddingReqInput,
     TokenizedGenerateReqInput,
 )
@@ -282,6 +283,9 @@ class DataParallelController:
                     ),
                 ):
                     self.dispatching(recv_req)
+                elif isinstance(recv_req, BlockReqInput):
+                    for worker in self.workers:
+                        worker.send_pyobj(recv_req)
                 else:
                     # Send other control messages to first worker of tp group
                     for worker in self.workers[:: self.control_message_step]:

python/sglang/srt/managers/io_struct.py

@@ -1103,3 +1103,13 @@ class LoRAUpdateResult:
 
 
 LoadLoRAAdapterReqOutput = UnloadLoRAAdapterReqOutput = LoRAUpdateResult
+
+
+class BlockReqType(Enum):
+    BLOCK = 1
+    UNBLOCK = 2
+
+
+@dataclass
+class BlockReqInput:
+    type: BlockReqType

python/sglang/srt/managers/scheduler.py

@@ -123,6 +123,7 @@ from sglang.srt.managers.schedule_policy import (
     PrefillAdder,
     SchedulePolicy,
 )
+from sglang.srt.managers.scheduler_input_blocker import SchedulerInputBlocker
 from sglang.srt.managers.scheduler_output_processor_mixin import (
     SchedulerOutputProcessorMixin,
 )
@@ -504,6 +505,12 @@ class Scheduler(
         )
         self.init_profier()
 
+        self.input_blocker = (
+            SchedulerInputBlocker(noop=self.attn_tp_rank != 0)
+            if get_bool_env_var("SGLANG_ENABLE_COLOCATED_BATCH_GEN")
+            else None
+        )
+
         # Init metrics stats
         self.init_metrics(tp_rank, pp_rank, dp_rank)
         self.init_kv_events(server_args.kv_events_config)
@@ -1035,6 +1042,9 @@ class Scheduler(
             else:
                 recv_reqs = None
 
+        if self.input_blocker is not None:
+            recv_reqs = self.input_blocker.handle(recv_reqs)
+
         if self.server_args.enable_dp_attention:
             if self.attn_tp_rank == 0:
                 work_reqs = [

python/sglang/srt/managers/scheduler_input_blocker.py

@@ -0,0 +1,106 @@
+# Copyright 2023-2024 SGLang Team
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+import logging
+from contextlib import contextmanager
+from enum import Enum, auto
+from typing import Any, List, Optional
+
+from sglang.srt.managers.io_struct import BlockReqInput, BlockReqType
+from sglang.srt.poll_based_barrier import PollBasedBarrier
+
+logger = logging.getLogger(__name__)
+
+
+class SchedulerInputBlocker:
+    def __init__(self, noop: bool):
+        self._state = _State.UNBLOCKED
+        self._pending_reqs = []
+        self._noop = noop
+        self._global_unblock_barrier = PollBasedBarrier(noop=noop)
+
+    def handle(self, recv_reqs: Optional[List[Any]]):
+        assert (recv_reqs is None) == self._noop
+
+        if not self._noop:
+            output_reqs = []
+            for recv_req in recv_reqs:
+                output_reqs += self._handle_recv_req(recv_req)
+
+        global_arrived_unblock_barrier = (
+            self._global_unblock_barrier.poll_global_arrived()
+        )
+        if (
+            self._state == _State.GLOBAL_UNBLOCK_BARRIER
+            and global_arrived_unblock_barrier
+        ):
+            output_reqs += self._handle_arrive_unblock_barrier()
+
+        if not self._noop:
+            return output_reqs
+
+    def _handle_recv_req(self, recv_req):
+        if isinstance(recv_req, BlockReqInput):
+            if recv_req.type == BlockReqType.BLOCK:
+                self._execute_block_req()
+                return []
+            elif recv_req.type == BlockReqType.UNBLOCK:
+                self._execute_unblock_req()
+                return []
+            else:
+                raise NotImplementedError(f"{recv_req=}")
+        else:
+            if self._state == _State.UNBLOCKED:
+                return [recv_req]
+            else:
+                self._pending_reqs.append(recv_req)
+                return []
+
+    def _execute_block_req(self):
+        logger.info("Handle block req")
+        self._change_state(original=_State.UNBLOCKED, target=_State.BLOCKED)
+
+    def _execute_unblock_req(self):
+        logger.info("Handle unblock req")
+        self._change_state(
+            original=_State.BLOCKED, target=_State.GLOBAL_UNBLOCK_BARRIER
+        )
+        self._global_unblock_barrier.local_arrive()
+
+    def _handle_arrive_unblock_barrier(self):
+        logger.info(f"Arrived at unblock barrier ({len(self._pending_reqs)=})")
+        self._change_state(
+            original=_State.GLOBAL_UNBLOCK_BARRIER, target=_State.UNBLOCKED
+        )
+        output_reqs = [*self._pending_reqs]
+        self._pending_reqs.clear()
+        return output_reqs
+
+    def _change_state(self, original: "_State", target: "_State"):
+        assert self._state == original, f"{self._state=} {original=} {target=}"
+        self._state = target
+
+
+class _State(Enum):
+    UNBLOCKED = auto()
+    BLOCKED = auto()
+    GLOBAL_UNBLOCK_BARRIER = auto()
+
+
+@contextmanager
+def input_blocker_guard_region(send_to_scheduler):
+    send_to_scheduler.send_pyobj(BlockReqInput(BlockReqType.BLOCK))
+    try:
+        yield
+    finally:
+        send_to_scheduler.send_pyobj(BlockReqInput(BlockReqType.UNBLOCK))

python/sglang/srt/managers/tokenizer_manager.py

@@ -27,6 +27,7 @@ import threading
 import time
 import uuid
 from collections import deque
+from contextlib import nullcontext
 from datetime import datetime
 from http import HTTPStatus
 from typing import (
@@ -69,6 +70,7 @@ from sglang.srt.managers.io_struct import (
     BatchMultimodalOut,
     BatchStrOut,
     BatchTokenIDOut,
+    BlockReqType,
     CloseSessionReqInput,
     ConfigureLoggingReq,
     EmbeddingReqInput,
@@ -114,6 +116,7 @@ from sglang.srt.managers.io_struct import (
 )
 from sglang.srt.managers.mm_utils import TensorTransportMode
 from sglang.srt.managers.multimodal_processor import get_mm_processor, import_processors
+from sglang.srt.managers.scheduler_input_blocker import input_blocker_guard_region
 from sglang.srt.metrics.collector import TokenizerMetricsCollector
 from sglang.srt.sampling.sampling_params import SamplingParams
 from sglang.srt.server_args import PortArgs, ServerArgs
@@ -819,12 +822,21 @@ class TokenizerManager:
                     rids.append(tmp_obj.rid)
             else:
                 # Sequential tokenization and processing
-                for i in range(batch_size):
-                    tmp_obj = obj[i]
-                    tokenized_obj = await self._tokenize_one_request(tmp_obj)
-                    state = self._send_one_request(tmp_obj, tokenized_obj, created_time)
-                    generators.append(self._wait_one_response(tmp_obj, state, request))
-                    rids.append(tmp_obj.rid)
+                with (
+                    input_blocker_guard_region(send_to_scheduler=self.send_to_scheduler)
+                    if get_bool_env_var("SGLANG_ENABLE_COLOCATED_BATCH_GEN")
+                    else nullcontext()
+                ):
+                    for i in range(batch_size):
+                        tmp_obj = obj[i]
+                        tokenized_obj = await self._tokenize_one_request(tmp_obj)
+                        state = self._send_one_request(
+                            tmp_obj, tokenized_obj, created_time
+                        )
+                        generators.append(
+                            self._wait_one_response(tmp_obj, state, request)
+                        )
+                        rids.append(tmp_obj.rid)
         else:
             # FIXME: When using batch and parallel_sample_num together, the perf is not optimal.
             if batch_size > 128:

python/sglang/srt/poll_based_barrier.py

@@ -0,0 +1,31 @@
+import torch
+
+from sglang.srt.distributed import get_world_group
+
+
+class PollBasedBarrier:
+    def __init__(self, noop: bool = False):
+        self._noop = noop
+        self._local_arrived = False
+
+    def local_arrive(self):
+        assert not self._local_arrived
+        self._local_arrived = True
+
+    def poll_global_arrived(self) -> bool:
+        global_arrived = self._compute_global_arrived()
+        output = self._local_arrived and global_arrived
+        if output:
+            self._local_arrived = False
+        return output
+
+    def _compute_global_arrived(self) -> bool:
+        local_arrived = self._noop or self._local_arrived
+        global_arrived = torch.tensor(local_arrived)
+        # Can optimize if bottleneck
+        torch.distributed.all_reduce(
+            global_arrived,
+            torch.distributed.ReduceOp.MIN,
+            group=get_world_group().cpu_group,
+        )
+        return global_arrived.item()