Files
xc-llm-ascend/vllm_ascend/core/recompute_scheduler.py
MengLong Chen 2d49f9079a [BugFix] Support ALL D-Nodes in fullgraph when running MTP in PD (#5472)
### What this PR does / why we need it?
**BUG**
When using prefill-decode disaggregation + MTP + full graph
+asynchronous scheduling, the KV cache pulled by decode nodes from
prefill decodes does not include spec tokens. As a result, the
total_num_scheduled_tokens obtained by decode nodes from the scheduler
lacks spec tokens. When determining whether to enqueue the full graph on
decode nodes, the condition for uniform_decode `
scheduler_output.total_num_scheduled_tokens == self.input_batch.num_reqs
* max_query_len` is not met, leading to the current instance not being
enqueued into the full graph.

The above situation leads to both full graph and eagle mode instances
coexisting in the decode instances. Due to the synchronization wait of
MoeDispatch, the decode instances in full graph are significantly slowed
down by the instance in eagle mode.

**Solution**
The scenario is PD separation + MTP + Full Graph + asynchronous
scheduling.
On the decode nodes, the spec tokens of the request with KV cache from P
need be padded. Then, the padded spec tokens will be rejected by
sampling. This operation ensures that the uniform_decode condition is
satisfied when determining whether decode nodes are included in the full
graph, thereby guaranteeing that all decode instances are present in the
full graph and avoiding synchronous waiting for MoeDispatch.

- vLLM version: v0.15.0
- vLLM main:
5326c89803

Signed-off-by: chenmenglong <chenmenglong1@huawei.com>
2026-02-26 19:09:05 +08:00

895 lines
43 KiB
Python

##
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
#
# 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.
# This file is a part of the vllm-ascend project.
# Adapted from vllm-project/vllm/vllm/v1/core/sched/scheduler.py
#
from __future__ import annotations
import time
from collections import defaultdict
from dataclasses import dataclass, fields
import numpy as np
from vllm._bc_linter import bc_linter_include
from vllm.config import SchedulerConfig, VllmConfig
from vllm.distributed.ec_transfer.ec_connector.base import ECConnectorMetadata
from vllm.distributed.kv_events import KVEventBatch
from vllm.distributed.kv_transfer.kv_connector.v1.base import KVConnectorMetadata
from vllm.distributed.kv_transfer.kv_connector.v1.metrics import KVConnectorStats
from vllm.logger import init_logger
from vllm.v1.core.kv_cache_manager import KVCacheBlocks
from vllm.v1.core.sched.async_scheduler import AsyncScheduler
from vllm.v1.core.sched.output import NewRequestData, SchedulerOutput
from vllm.v1.core.sched.request_queue import SchedulingPolicy, create_request_queue
from vllm.v1.core.sched.scheduler import Scheduler
from vllm.v1.core.sched.utils import remove_all
from vllm.v1.engine import EngineCoreEventType, EngineCoreOutput, EngineCoreOutputs, FinishReason
from vllm.v1.metrics.perf import PerfStats
from vllm.v1.outputs import ModelRunnerOutput
from vllm.v1.request import Request, RequestStatus
from vllm.v1.sample.rejection_sampler import PLACEHOLDER_TOKEN_ID
from vllm.v1.spec_decode.metrics import SpecDecodingStats
from vllm.v1.utils import ConstantList, record_function_or_nullcontext
logger = init_logger(__name__)
@dataclass
class RecomputeSchedulerConfig(SchedulerConfig):
scheduler_cls: str | type[object] = "vllm_ascend.core.recompute_scheduler.RecomputeScheduler"
@classmethod
def initialize_from_config(cls, vllm_config: VllmConfig):
vllm_scheduler_config = vllm_config.scheduler_config
scheduler_config = {
field.name: getattr(vllm_scheduler_config, field.name)
for field in fields(vllm_scheduler_config)
if field.init
}
if vllm_scheduler_config.async_scheduling:
scheduler_config["scheduler_cls"] = "vllm_ascend.core.recompute_scheduler.AsyncRecomputeScheduler"
else:
scheduler_config["scheduler_cls"] = "vllm_ascend.core.recompute_scheduler.RecomputeScheduler"
scheduler_config["max_model_len"] = vllm_config.model_config.max_model_len
scheduler_config["is_encoder_decoder"] = vllm_config.model_config.is_encoder_decoder
return cls(**scheduler_config)
@dataclass
class RecomputeReqInfo:
request_id: str
output_token_ids: ConstantList
client_index: int = 0
@bc_linter_include
@dataclass
class RecomputeSchedulerOutput(SchedulerOutput):
recomputed_reqs: list[RecomputeReqInfo] | None = None
class RecomputeScheduler(Scheduler):
running: list[Request]
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# When is_mtp_kv_consumer is true, we will fill request.spec_token_ids
# with placeholder tokens to enable full graph when decode nodes pull
# the KV cache of one request from prefill nodes.
self.is_mtp_kv_consumer = (
self.vllm_config.speculative_config
and self.vllm_config.kv_transfer_config
and self.vllm_config.kv_transfer_config.is_kv_consumer
)
def add_request(self, request: Request) -> None:
# Fill in placeholder tokens to enable full graph compatibility. Without
# placeholders, graph matching may fail, forcing eager mode execution.
if self.is_mtp_kv_consumer:
request.spec_token_ids = [PLACEHOLDER_TOKEN_ID] * self.num_spec_tokens
self.waiting.add_request(request)
self.requests[request.request_id] = request
if self.log_stats:
request.record_event(EngineCoreEventType.QUEUED)
def schedule(self) -> RecomputeSchedulerOutput:
# NOTE(woosuk) on the scheduling algorithm:
# There's no "decoding phase" nor "prefill phase" in the scheduler.
# Each request just has the num_computed_tokens and
# num_tokens_with_spec. num_tokens_with_spec =
# len(prompt_token_ids) + len(output_token_ids) + len(spec_token_ids).
# At each step, the scheduler tries to assign tokens to the requests
# so that each request's num_computed_tokens can catch up its
# num_tokens_with_spec. This is general enough to cover
# chunked prefills, prefix caching, speculative decoding,
# and the "jump decoding" optimization in the future.
scheduled_new_reqs: list[Request] = []
scheduled_resumed_reqs: list[Request] = []
scheduled_running_reqs: list[Request] = []
preempted_reqs: list[Request] = []
recomputed_reqs: list[RecomputeReqInfo] = []
req_to_new_blocks: dict[str, KVCacheBlocks] = {}
num_scheduled_tokens: dict[str, int] = {}
token_budget = self.max_num_scheduled_tokens
# Encoder-related.
scheduled_encoder_inputs: dict[str, list[int]] = {}
encoder_compute_budget = self.max_num_encoder_input_tokens
# Spec decode-related.
scheduled_spec_decode_tokens: dict[str, list[int]] = {}
# For logging.
scheduled_timestamp = time.monotonic()
# First, schedule the RUNNING requests.
req_index = 0
while req_index < len(self.running) and token_budget > 0:
request = self.running[req_index]
if (
request.num_output_placeholders > 0
# This is (num_computed_tokens + 1) - (num_output_placeholders - 1).
# Since output placeholders are also included in the computed tokens
# count, we subtract (num_output_placeholders - 1) to remove any draft
# tokens, so that we can be sure no further steps are needed even if
# they are all rejected.
and request.num_computed_tokens + 2 - request.num_output_placeholders
>= request.num_prompt_tokens + request.max_tokens
):
# Async scheduling: Avoid scheduling an extra step when we are sure that
# the previous step has reached request.max_tokens. We don't schedule
# partial draft tokens since this prevents uniform decode optimizations.
req_index += 1
continue
num_new_tokens = (
request.num_tokens_with_spec + request.num_output_placeholders - request.num_computed_tokens
)
if 0 < self.scheduler_config.long_prefill_token_threshold < num_new_tokens:
num_new_tokens = self.scheduler_config.long_prefill_token_threshold
num_new_tokens = min(num_new_tokens, token_budget)
# Make sure the input position does not exceed the max model len.
# This is necessary when using spec decoding.
num_new_tokens = min(num_new_tokens, self.max_model_len - 1 - request.num_computed_tokens)
# Schedule encoder inputs.
encoder_inputs_to_schedule = None
external_load_encoder_input: list[int] = []
new_encoder_compute_budget = encoder_compute_budget
if request.has_encoder_inputs:
(
encoder_inputs_to_schedule,
num_new_tokens,
new_encoder_compute_budget,
external_load_encoder_input,
) = self._try_schedule_encoder_inputs(
request,
request.num_computed_tokens,
num_new_tokens,
encoder_compute_budget,
shift_computed_tokens=1 if self.use_eagle else 0,
)
if num_new_tokens == 0:
# The request cannot be scheduled because one of the following
# reasons:
# 1. No new tokens to schedule. This may happen when
# (1) PP>1 and we have already scheduled all prompt tokens
# but they are not finished yet.
# (2) Async scheduling and the request has reached to either
# its max_total_tokens or max_model_len.
# 2. The encoder budget is exhausted.
# 3. The encoder cache is exhausted.
# NOTE(woosuk): Here, by doing `continue` instead of `break`,
# we do not strictly follow the FCFS scheduling policy and
# allow the lower-priority requests to be scheduled.
req_index += 1
continue
# Schedule newly needed KV blocks for the request.
with record_function_or_nullcontext("schedule: allocate_slots"):
while True:
new_blocks = self.kv_cache_manager.allocate_slots(
request,
num_new_tokens,
num_lookahead_tokens=self.num_lookahead_tokens,
)
if new_blocks is not None:
# The request can be scheduled.
break
# The request cannot be scheduled.
# Preempt the lowest-priority request.
# NOTE: We add the preempted_req to recomputed_reqs in kv_consumer to
# drop the request to PD proxy.
transfer_config = self.vllm_config.kv_transfer_config
if transfer_config is not None and not transfer_config.is_kv_producer:
recomputed_req = self.running.pop()
self.kv_cache_manager.free(recomputed_req)
recomputed_reqs.append(
RecomputeReqInfo(
recomputed_req.request_id, recomputed_req.output_token_ids, recomputed_req.client_index
)
)
if recomputed_req == request:
break
else:
if self.policy == SchedulingPolicy.PRIORITY:
preempted_req = max(
self.running,
key=lambda r: (r.priority, r.arrival_time),
)
self.running.remove(preempted_req)
if preempted_req in scheduled_running_reqs:
scheduled_running_reqs.remove(preempted_req)
token_budget += num_scheduled_tokens[preempted_req.request_id]
req_to_new_blocks.pop(preempted_req.request_id)
num_scheduled_tokens.pop(preempted_req.request_id)
scheduled_spec_decode_tokens.pop(preempted_req.request_id, None)
preempted_encoder_inputs = scheduled_encoder_inputs.pop(preempted_req.request_id, None)
if preempted_encoder_inputs:
# Restore encoder compute budget if the preempted
# request had encoder inputs scheduled in this step.
num_embeds_to_restore = sum(
preempted_req.get_num_encoder_embeds(i) for i in preempted_encoder_inputs
)
encoder_compute_budget += num_embeds_to_restore
req_index -= 1
else:
preempted_req = self.running.pop()
self._preempt_request(preempted_req, scheduled_timestamp)
preempted_reqs.append(preempted_req)
if preempted_req == request:
# No more request to preempt. Cannot schedule this request.
break
if new_blocks is None:
# Cannot schedule this request.
break
# Schedule the request.
scheduled_running_reqs.append(request)
req_to_new_blocks[request.request_id] = new_blocks
num_scheduled_tokens[request.request_id] = num_new_tokens
token_budget -= num_new_tokens
req_index += 1
# Speculative decode related.
if request.spec_token_ids:
num_scheduled_spec_tokens = (
num_new_tokens + request.num_computed_tokens - request.num_tokens - request.num_output_placeholders
)
if num_scheduled_spec_tokens > 0:
# Trim spec_token_ids list to num_scheduled_spec_tokens.
del request.spec_token_ids[num_scheduled_spec_tokens:]
scheduled_spec_decode_tokens[request.request_id] = request.spec_token_ids
# New spec tokens will be set in `update_draft_token_ids` before the
# next step when applicable.
request.spec_token_ids = []
# Encoder-related.
if encoder_inputs_to_schedule:
scheduled_encoder_inputs[request.request_id] = encoder_inputs_to_schedule
# Allocate the encoder cache.
for i in encoder_inputs_to_schedule:
self.encoder_cache_manager.allocate(request, i)
encoder_compute_budget = new_encoder_compute_budget
if external_load_encoder_input:
for i in external_load_encoder_input:
self.encoder_cache_manager.allocate(request, i)
if self.ec_connector is not None:
self.ec_connector.update_state_after_alloc(request, i)
# Record the LoRAs in scheduled_running_reqs
scheduled_loras: set[int] = set()
if self.lora_config:
scheduled_loras = set(
req.lora_request.lora_int_id
for req in scheduled_running_reqs
if req.lora_request and req.lora_request.lora_int_id > 0
)
assert len(scheduled_loras) <= self.lora_config.max_loras
# Use a temporary RequestQueue to collect requests that need to be
# skipped and put back at the head of the waiting queue later
skipped_waiting_requests = create_request_queue(self.policy)
# Next, schedule the WAITING requests.
if not preempted_reqs and not recomputed_reqs:
while self.waiting and token_budget > 0:
if len(self.running) == self.max_num_running_reqs:
break
request = self.waiting.peek_request()
# KVTransfer: skip request if still waiting for remote kvs.
if request.status == RequestStatus.WAITING_FOR_REMOTE_KVS:
is_ready = self._update_waiting_for_remote_kv(request)
if is_ready:
if request.num_preemptions:
# We must be loading for a resumed preemption
# rather than a new request.
request.status = RequestStatus.PREEMPTED
else:
request.status = RequestStatus.WAITING
else:
logger.debug(
"%s is still in WAITING_FOR_REMOTE_KVS state.",
request.request_id,
)
self.waiting.pop_request()
skipped_waiting_requests.prepend_request(request)
continue
# Skip request if the structured output request is still waiting
# for FSM compilation.
if request.status == RequestStatus.WAITING_FOR_FSM:
structured_output_req = request.structured_output_request
if structured_output_req and structured_output_req.grammar:
request.status = RequestStatus.WAITING
else:
self.waiting.pop_request()
skipped_waiting_requests.prepend_request(request)
continue
# Check that adding the request still respects the max_loras
# constraint.
if (
self.lora_config
and request.lora_request
and (
len(scheduled_loras) == self.lora_config.max_loras
and request.lora_request.lora_int_id not in scheduled_loras
)
):
# Scheduling would exceed max_loras, skip.
self.waiting.pop_request()
skipped_waiting_requests.prepend_request(request)
continue
num_external_computed_tokens = 0
load_kv_async = False
# Get already-cached tokens.
if request.num_computed_tokens == 0:
# Get locally-cached tokens.
new_computed_blocks, num_new_local_computed_tokens = self.kv_cache_manager.get_computed_blocks(
request
)
# Get externally-cached tokens if using a KVConnector.
if self.connector is not None:
ext_tokens, load_kv_async = self.connector.get_num_new_matched_tokens(
request, num_new_local_computed_tokens
)
if ext_tokens is None:
# The request cannot be scheduled because
# the KVConnector couldn't determine
# the number of matched tokens.
self.waiting.pop_request()
skipped_waiting_requests.prepend_request(request)
continue
request.num_external_computed_tokens = ext_tokens
num_external_computed_tokens = ext_tokens
# Total computed tokens (local + external).
num_computed_tokens = num_new_local_computed_tokens + num_external_computed_tokens
else:
# KVTransfer: WAITING reqs have num_computed_tokens > 0
# after async KV recvs are completed.
new_computed_blocks = self.kv_cache_manager.empty_kv_cache_blocks
num_new_local_computed_tokens = 0
num_computed_tokens = request.num_computed_tokens
encoder_inputs_to_schedule = None
external_load_encoder_input = []
new_encoder_compute_budget = encoder_compute_budget
if load_kv_async:
# KVTransfer: loading remote KV, do not allocate for new work.
assert num_external_computed_tokens > 0
num_new_tokens = 0
else:
# Number of tokens to be scheduled.
# We use `request.num_tokens` instead of
# `request.num_prompt_tokens` to consider the resumed
# requests, which have output tokens.
if self.is_mtp_kv_consumer:
num_new_tokens = request.num_tokens_with_spec - num_computed_tokens
else:
num_new_tokens = request.num_tokens - num_computed_tokens
threshold = self.scheduler_config.long_prefill_token_threshold
if 0 < threshold < num_new_tokens:
num_new_tokens = threshold
# chunked prefill has to be enabled explicitly to allow
# pooling requests to be chunked
if not self.scheduler_config.enable_chunked_prefill and num_new_tokens > token_budget:
# If chunked_prefill is disabled,
# we can stop the scheduling here.
break
num_new_tokens = min(num_new_tokens, token_budget)
assert num_new_tokens > 0
# Schedule encoder inputs.
if request.has_encoder_inputs:
(
encoder_inputs_to_schedule,
num_new_tokens,
new_encoder_compute_budget,
external_load_encoder_input,
) = self._try_schedule_encoder_inputs(
request,
num_computed_tokens,
num_new_tokens,
encoder_compute_budget,
shift_computed_tokens=1 if self.use_eagle else 0,
)
if num_new_tokens == 0:
# The request cannot be scheduled.
break
# Handles an edge case when P/D Disaggregation
# is used with Spec Decoding where an
# extra block gets allocated which
# creates a mismatch between the number
# of local and remote blocks.
effective_lookahead_tokens = 0 if request.num_computed_tokens == 0 else self.num_lookahead_tokens
num_encoder_tokens = (
self._num_encoder_max_input_tokens if self.is_encoder_decoder and request.has_encoder_inputs else 0
)
new_blocks = self.kv_cache_manager.allocate_slots(
request,
num_new_tokens,
num_new_computed_tokens=num_new_local_computed_tokens,
new_computed_blocks=new_computed_blocks,
num_lookahead_tokens=effective_lookahead_tokens,
num_external_computed_tokens=num_external_computed_tokens,
delay_cache_blocks=load_kv_async,
num_encoder_tokens=num_encoder_tokens,
)
if new_blocks is None:
# The request cannot be scheduled.
# NOTE: we need to untouch the request from the encode cache
# manager
if request.has_encoder_inputs:
self.encoder_cache_manager.free(request)
break
# KVTransfer: the connector uses this info to determine
# if a load is needed. Note that
# This information is used to determine if a load is
# needed for this request.
if self.connector is not None:
self.connector.update_state_after_alloc(
request,
self.kv_cache_manager.get_blocks(request.request_id),
num_external_computed_tokens,
)
# Request was already popped from self.waiting
# unless it was re-added above due to new_blocks being None.
request = self.waiting.pop_request()
if load_kv_async:
# If loading async, allocate memory and put request
# into the WAITING_FOR_REMOTE_KV state.
skipped_waiting_requests.prepend_request(request)
request.status = RequestStatus.WAITING_FOR_REMOTE_KVS
continue
self._update_connector_prefix_cache_stats(request)
# For spec_token_ids, the waiting queue has the same processing
# as the running queue.
if self.is_mtp_kv_consumer and request.spec_token_ids:
num_scheduled_spec_tokens = (
num_new_tokens
+ request.num_computed_tokens
- request.num_tokens
- request.num_output_placeholders
)
if num_scheduled_spec_tokens > 0:
# Trim spec_token_ids list to num_scheduled_spec_tokens.
del request.spec_token_ids[num_scheduled_spec_tokens:]
scheduled_spec_decode_tokens[request.request_id] = request.spec_token_ids
# New spec tokens will be set in `update_draft_token_ids` before the
# next step when applicable.
request.spec_token_ids = []
self.running.append(request)
if self.log_stats:
request.record_event(EngineCoreEventType.SCHEDULED, scheduled_timestamp)
if request.status == RequestStatus.WAITING:
scheduled_new_reqs.append(request)
elif request.status == RequestStatus.PREEMPTED:
scheduled_resumed_reqs.append(request)
else:
raise RuntimeError(f"Invalid request status: {request.status}")
if self.lora_config and request.lora_request:
scheduled_loras.add(request.lora_request.lora_int_id)
req_to_new_blocks[request.request_id] = self.kv_cache_manager.get_blocks(request.request_id)
num_scheduled_tokens[request.request_id] = num_new_tokens
token_budget -= num_new_tokens
request.status = RequestStatus.RUNNING
request.num_computed_tokens = num_computed_tokens
# Count the number of prefix cached tokens.
if request.num_cached_tokens < 0:
request.num_cached_tokens = num_computed_tokens
# Encoder-related.
if encoder_inputs_to_schedule:
scheduled_encoder_inputs[request.request_id] = encoder_inputs_to_schedule
# Allocate the encoder cache.
for i in encoder_inputs_to_schedule:
self.encoder_cache_manager.allocate(request, i)
encoder_compute_budget = new_encoder_compute_budget
# Allocate for external load encoder cache
if external_load_encoder_input:
for i in external_load_encoder_input:
self.encoder_cache_manager.allocate(request, i)
if self.ec_connector is not None:
self.ec_connector.update_state_after_alloc(request, i)
# Put back any skipped requests at the head of the waiting queue
if skipped_waiting_requests:
self.waiting.prepend_requests(skipped_waiting_requests)
# Check if the scheduling constraints are satisfied.
total_num_scheduled_tokens = sum(num_scheduled_tokens.values())
assert total_num_scheduled_tokens <= self.max_num_scheduled_tokens
assert token_budget >= 0
assert len(self.running) <= self.max_num_running_reqs
# Since some requests in the RUNNING queue may not be scheduled in
# this step, the total number of scheduled requests can be smaller than
# len(self.running).
assert len(scheduled_new_reqs) + len(scheduled_resumed_reqs) + len(scheduled_running_reqs) <= len(self.running)
# Get the longest common prefix among all requests in the running queue.
# This can be potentially used for cascade attention.
num_common_prefix_blocks = [0] * len(self.kv_cache_config.kv_cache_groups)
with record_function_or_nullcontext("schedule: get_num_common_prefix_blocks"):
if self.running:
any_request = self.running[0]
num_common_prefix_blocks = self.kv_cache_manager.get_num_common_prefix_blocks(any_request.request_id)
# Construct the scheduler output.
if self.use_v2_model_runner:
scheduled_new_reqs = scheduled_new_reqs + scheduled_resumed_reqs
scheduled_resumed_reqs = []
new_reqs_data = [
NewRequestData.from_request(
req,
req_to_new_blocks[req.request_id].get_block_ids(),
req._all_token_ids,
)
for req in scheduled_new_reqs
]
else:
new_reqs_data = [
NewRequestData.from_request(req, req_to_new_blocks[req.request_id].get_block_ids())
for req in scheduled_new_reqs
]
with record_function_or_nullcontext("schedule: make_cached_request_data"):
cached_reqs_data = self._make_cached_request_data(
scheduled_running_reqs,
scheduled_resumed_reqs,
num_scheduled_tokens,
scheduled_spec_decode_tokens,
req_to_new_blocks,
)
# Record the request ids that were scheduled in this step.
self.prev_step_scheduled_req_ids.clear()
self.prev_step_scheduled_req_ids.update(num_scheduled_tokens.keys())
scheduler_output = RecomputeSchedulerOutput(
scheduled_new_reqs=new_reqs_data,
scheduled_cached_reqs=cached_reqs_data,
num_scheduled_tokens=num_scheduled_tokens,
total_num_scheduled_tokens=total_num_scheduled_tokens,
scheduled_spec_decode_tokens=scheduled_spec_decode_tokens,
scheduled_encoder_inputs=scheduled_encoder_inputs,
num_common_prefix_blocks=num_common_prefix_blocks,
preempted_req_ids={req.request_id for req in preempted_reqs},
# finished_req_ids is an existing state in the scheduler,
# instead of being newly scheduled in this step.
# It contains the request IDs that are finished in between
# the previous and the current steps.
finished_req_ids=self.finished_req_ids,
free_encoder_mm_hashes=self.encoder_cache_manager.get_freed_mm_hashes(),
recomputed_reqs=recomputed_reqs,
)
# NOTE(Kuntai): this function is designed for multiple purposes:
# 1. Plan the KV cache store
# 2. Wrap up all the KV cache load / save ops into an opaque object
# 3. Clear the internal states of the connector
if self.connector is not None:
meta: KVConnectorMetadata = self.connector.build_connector_meta(scheduler_output)
scheduler_output.kv_connector_metadata = meta
# Build the connector meta for ECConnector
if self.ec_connector is not None:
ec_meta: ECConnectorMetadata = self.ec_connector.build_connector_meta(scheduler_output)
scheduler_output.ec_connector_metadata = ec_meta
with record_function_or_nullcontext("schedule: update_after_schedule"):
self._update_after_schedule(scheduler_output)
return scheduler_output
def update_from_output(
self,
scheduler_output: RecomputeSchedulerOutput,
model_runner_output: ModelRunnerOutput,
) -> dict[int, EngineCoreOutputs]:
sampled_token_ids = model_runner_output.sampled_token_ids
logprobs = model_runner_output.logprobs
prompt_logprobs_dict = model_runner_output.prompt_logprobs_dict
num_scheduled_tokens = scheduler_output.num_scheduled_tokens
pooler_outputs = model_runner_output.pooler_output
num_nans_in_logits = model_runner_output.num_nans_in_logits
kv_connector_output = model_runner_output.kv_connector_output
cudagraph_stats = model_runner_output.cudagraph_stats
perf_stats: PerfStats | None = None
if self.perf_metrics and self.perf_metrics.is_enabled():
perf_stats = self.perf_metrics.get_step_perf_stats_per_gpu(scheduler_output)
outputs: dict[int, list[EngineCoreOutput]] = defaultdict(list)
spec_decoding_stats: SpecDecodingStats | None = None
kv_connector_stats: KVConnectorStats | None = (
kv_connector_output.kv_connector_stats if kv_connector_output else None
)
if kv_connector_stats and self.connector:
kv_stats = self.connector.get_kv_connector_stats()
if kv_stats:
kv_connector_stats = kv_connector_stats.aggregate(kv_stats)
failed_kv_load_req_ids = None
if kv_connector_output and kv_connector_output.invalid_block_ids:
# These blocks contain externally computed tokens that failed to
# load. Identify affected requests and adjust their computed token
# count to trigger recomputation of the invalid blocks.
failed_kv_load_req_ids = self._handle_invalid_blocks(kv_connector_output.invalid_block_ids)
# return recomputed requests as EngineCoreOutput
if scheduler_output.recomputed_reqs is not None:
for req_info in scheduler_output.recomputed_reqs:
outputs[req_info.client_index].append(
EngineCoreOutput(
request_id=req_info.request_id,
finish_reason=FinishReason.STOP,
new_token_ids=[],
stop_reason="recomputed",
)
)
# NOTE(woosuk): As len(num_scheduled_tokens) can be up to 1K or more,
# the below loop can be a performance bottleneck. We should do our best
# to avoid expensive operations inside the loop.
stopped_running_reqs: set[Request] = set()
stopped_preempted_reqs: set[Request] = set()
for req_id, num_tokens_scheduled in num_scheduled_tokens.items():
assert num_tokens_scheduled > 0
if failed_kv_load_req_ids and req_id in failed_kv_load_req_ids:
# skip failed or rescheduled requests from KV load failure
continue
request = self.requests.get(req_id)
if request is None:
# The request is already finished. This can happen if the
# request is aborted while the model is executing it (e.g.,
# in pipeline parallelism).
continue
req_index = model_runner_output.req_id_to_index[req_id]
generated_token_ids = sampled_token_ids[req_index] if sampled_token_ids else []
scheduled_spec_token_ids = scheduler_output.scheduled_spec_decode_tokens.get(req_id)
if scheduled_spec_token_ids:
num_draft_tokens = len(scheduled_spec_token_ids)
num_accepted = len(generated_token_ids) - 1
num_rejected = num_draft_tokens - num_accepted
# num_computed_tokens represents the number of tokens
# processed in the current step, considering scheduled
# tokens and rejections. If some tokens are rejected,
# num_computed_tokens is decreased by the number of rejected
# tokens.
if request.num_computed_tokens > 0:
request.num_computed_tokens -= num_rejected
# If async scheduling, num_output_placeholders also includes
# the scheduled spec tokens count and so is similarly adjusted.
if request.num_output_placeholders > 0:
request.num_output_placeholders -= num_rejected
spec_decoding_stats = self.make_spec_decoding_stats(
spec_decoding_stats,
num_draft_tokens=num_draft_tokens,
num_accepted_tokens=num_accepted,
num_invalid_spec_tokens=scheduler_output.num_invalid_spec_tokens,
request_id=req_id,
)
stopped = False
new_logprobs = None
new_token_ids = generated_token_ids
pooler_output = pooler_outputs[req_index] if pooler_outputs else None
kv_transfer_params = None
status_before_stop = request.status
# Check for stop and update request status.
if new_token_ids:
new_token_ids, stopped = self._update_request_with_output(request, new_token_ids)
elif request.pooling_params and pooler_output is not None:
# Pooling stops as soon as there is output.
request.status = RequestStatus.FINISHED_STOPPED
stopped = True
routed_experts = None
if stopped:
if self.vllm_config.model_config.enable_return_routed_experts:
kv_blocks = self.kv_cache_manager.get_blocks(request.request_id)
block_ids = kv_blocks.get_block_ids()[0]
num_tokens = request.num_tokens - 1
# compute slot mapping
block_ids_array = np.array(block_ids, dtype=np.int32)
num_blocks = len(block_ids)
block_size = self.block_size
# generate block offsets
block_offsets = np.arange(0, block_size)
# compute slot mapping: slot = block_id * block_size + offset
slot_mapping = (
block_offsets.reshape((1, block_size)) + block_ids_array.reshape((num_blocks, 1)) * block_size
).flatten()[:num_tokens]
routed_experts = self.routed_experts_reader.get_routed_experts(indices=slot_mapping)
kv_transfer_params = self._free_request(request)
if status_before_stop == RequestStatus.RUNNING:
stopped_running_reqs.add(request)
else:
stopped_preempted_reqs.add(request)
# Extract sample logprobs if needed.
if request.sampling_params is not None and request.sampling_params.logprobs is not None and logprobs:
new_logprobs = logprobs.slice_request(req_index, len(new_token_ids))
if new_token_ids and self.structured_output_manager.should_advance(request):
struct_output_request = request.structured_output_request
assert struct_output_request is not None
assert struct_output_request.grammar is not None
ok = struct_output_request.grammar.accept_tokens(req_id, new_token_ids)
if not ok:
logger.warning(
"Unexpected: grammar rejected tokens %s for request %s.",
new_token_ids,
req_id,
)
if num_nans_in_logits is not None and req_id in num_nans_in_logits:
request.num_nans_in_logits = num_nans_in_logits[req_id]
# Get prompt logprobs for this request.
prompt_logprobs_tensors = prompt_logprobs_dict.get(req_id)
if new_token_ids or pooler_output is not None or kv_transfer_params:
# Add EngineCoreOutput for this Request.
outputs[request.client_index].append(
EngineCoreOutput(
request_id=req_id,
new_token_ids=new_token_ids,
finish_reason=request.get_finished_reason(),
new_logprobs=new_logprobs,
new_prompt_logprobs_tensors=prompt_logprobs_tensors,
pooling_output=pooler_output,
stop_reason=request.stop_reason,
events=request.take_events(),
kv_transfer_params=kv_transfer_params,
trace_headers=request.trace_headers,
num_cached_tokens=request.num_cached_tokens,
routed_experts=routed_experts,
num_nans_in_logits=request.num_nans_in_logits,
)
)
else:
# Invariant: EngineCore returns no partial prefill outputs.
assert not prompt_logprobs_tensors
# Remove the stopped requests from the running and waiting queues.
if stopped_running_reqs:
self.running = remove_all(self.running, stopped_running_reqs)
if stopped_preempted_reqs:
# This is a rare case and unlikely to impact performance.
self.waiting.remove_requests(stopped_preempted_reqs)
if failed_kv_load_req_ids and not self.recompute_kv_load_failures:
requests = [self.requests[req_id] for req_id in failed_kv_load_req_ids]
self.finish_requests(failed_kv_load_req_ids, RequestStatus.FINISHED_ERROR)
for request in requests:
outputs[request.client_index].append(
EngineCoreOutput(
request_id=request.request_id,
new_token_ids=[],
finish_reason=request.get_finished_reason(),
events=request.take_events(),
trace_headers=request.trace_headers,
num_cached_tokens=request.num_cached_tokens,
)
)
# KV Connector: update state for finished KV Transfers.
if kv_connector_output:
self._update_from_kv_xfer_finished(kv_connector_output)
# collect KV cache events from KV cache manager
events = self.kv_cache_manager.take_events()
# collect KV cache events from connector
if self.connector is not None:
connector_events = self.connector.take_events()
if connector_events:
if events is None:
events = list(connector_events)
else:
events.extend(connector_events)
# publish collected KV cache events
if events:
batch = KVEventBatch(ts=time.time(), events=events)
self.kv_event_publisher.publish(batch)
# Create EngineCoreOutputs for all clients that have requests with
# outputs in this step.
engine_core_outputs = {client_index: EngineCoreOutputs(outputs=outs) for client_index, outs in outputs.items()}
finished_req_ids = self.finished_req_ids_dict
if finished_req_ids:
# Include ids of requests that finished since last outputs
# were sent.
for client_index, finished_set in finished_req_ids.items():
# Set finished request set in EngineCoreOutputs for this client.
if (eco := engine_core_outputs.get(client_index)) is not None:
eco.finished_requests = finished_set
else:
engine_core_outputs[client_index] = EngineCoreOutputs(finished_requests=finished_set)
finished_req_ids.clear()
if (stats := self.make_stats(spec_decoding_stats, kv_connector_stats, cudagraph_stats, perf_stats)) is not None:
# Return stats to only one of the front-ends.
if (eco := next(iter(engine_core_outputs.values()), None)) is None:
# We must return the stats even if there are no request
# outputs this step.
engine_core_outputs[0] = eco = EngineCoreOutputs()
eco.scheduler_stats = stats
return engine_core_outputs
class AsyncRecomputeScheduler(AsyncScheduler, RecomputeScheduler):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)