[V1][Spec Decode] Ngram Spec Decode (#12193)

Signed-off-by: LiuXiaoxuanPKU <lilyliupku@gmail.com>
This commit is contained in:
Lily Liu
2025-02-15 18:05:11 -08:00
committed by GitHub
parent 367cb8ce8c
commit 80f63a3966
21 changed files with 1023 additions and 82 deletions

View File

@@ -4,10 +4,12 @@ from typing import List, Optional
from vllm.config import CacheConfig, ModelConfig, SchedulerConfig
from vllm.multimodal.inputs import MultiModalKwargs, PlaceholderRange
from vllm.sampling_params import SamplingParams
from vllm.v1.core.scheduler import Scheduler
from vllm.v1.core.scheduler import Scheduler, SchedulerOutput
from vllm.v1.outputs import ModelRunnerOutput
from vllm.v1.request import Request, RequestStatus
EOS_TOKEN_ID = 50256
def create_scheduler(
model: str = "facebook/opt-125m",
@@ -38,6 +40,7 @@ def create_scheduler(
return Scheduler(scheduler_config,
model_config,
cache_config,
speculative_config=None,
lora_config=None,
log_stats=True)
@@ -46,8 +49,12 @@ def create_requests(
num_requests: int,
num_tokens: int = 10,
mm_positions: Optional[List[PlaceholderRange]] = None,
max_tokens: int = 16,
stop_token_ids: Optional[List[int]] = None,
):
sampling_params = SamplingParams()
sampling_params = SamplingParams(ignore_eos=False,
max_tokens=max_tokens,
stop_token_ids=stop_token_ids)
requests = []
for i in range(num_requests):
if mm_positions is not None:
@@ -64,7 +71,7 @@ def create_requests(
multi_modal_inputs=mm_inputs,
multi_modal_placeholders=mm_position,
multi_modal_hashes=None,
eos_token_id=None,
eos_token_id=EOS_TOKEN_ID,
arrival_time=0,
)
requests.append(request)
@@ -195,7 +202,7 @@ def test_schedule_partial_requests():
model_runner_output = ModelRunnerOutput(
req_ids=[request.request_id for request in requests],
req_id_to_index=req_to_index,
sampled_token_ids=[0] * len(requests),
sampled_token_ids=[[0] for _ in range(len(requests))],
logprobs=None,
prompt_logprobs_dict={},
)
@@ -215,6 +222,189 @@ def test_schedule_partial_requests():
assert requests[2].request_id not in output.num_scheduled_tokens
def test_stop_via_update_from_output():
"""Test stopping behavior through update_from_output"""
scheduler = create_scheduler()
# Test case 1: Stop on EOS token
requests = create_requests(num_requests=2, max_tokens=10)
for req in requests:
req.num_computed_tokens = req.num_tokens
scheduler.requests[req.request_id] = req
scheduler.running.append(req)
scheduler.scheduled_req_ids.add(req.request_id)
scheduler_output = SchedulerOutput(scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={
requests[0].request_id: 1,
requests[1].request_id: 2
},
total_num_scheduled_tokens=3,
scheduled_encoder_inputs={},
scheduled_spec_decode_tokens={
requests[0].request_id: [],
requests[1].request_id: [10]
},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[])
model_output = ModelRunnerOutput(
req_ids=[req.request_id for req in requests],
req_id_to_index={
req.request_id: i
for i, req in enumerate(requests)
},
sampled_token_ids=[[EOS_TOKEN_ID],
[10,
11]], # First request hits EOS, second continues
logprobs=None,
prompt_logprobs_dict={})
scheduler.update_from_output(scheduler_output, model_output)
# Verify first request stopped, second continues
assert len(scheduler.running) == 1
assert scheduler.running[0].request_id == requests[1].request_id
assert requests[0].status == RequestStatus.FINISHED_STOPPED
assert requests[0].request_id in scheduler.finished_req_ids
assert list(requests[0].output_token_ids) == [EOS_TOKEN_ID]
assert list(requests[1].output_token_ids) == [10, 11]
# Test case 2: Stop on custom stop token
scheduler = create_scheduler()
requests = create_requests(num_requests=2,
max_tokens=10,
stop_token_ids=[42, 43])
for req in requests:
req.num_computed_tokens = req.num_tokens
scheduler.requests[req.request_id] = req
scheduler.running.append(req)
scheduler.scheduled_req_ids.add(req.request_id)
scheduler_output = SchedulerOutput(scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={
requests[0].request_id: 3,
requests[1].request_id: 2
},
total_num_scheduled_tokens=5,
scheduled_encoder_inputs={},
scheduled_spec_decode_tokens={
requests[0].request_id: [10, 42],
requests[1].request_id: [13]
},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[])
model_output = ModelRunnerOutput(
req_ids=[req.request_id for req in requests],
req_id_to_index={
req.request_id: i
for i, req in enumerate(requests)
},
sampled_token_ids=[[10, 42, 12],
[13, 14]], # First request hits stop token
logprobs=None,
prompt_logprobs_dict={})
scheduler.update_from_output(scheduler_output, model_output)
# Verify first request stopped on custom token
assert len(scheduler.running) == 1
assert scheduler.running[0].request_id == requests[1].request_id
assert requests[0].status == RequestStatus.FINISHED_STOPPED
assert requests[0].stop_reason == 42
assert requests[0].request_id in scheduler.finished_req_ids
assert list(requests[0].output_token_ids) == [10, 42]
assert list(requests[1].output_token_ids) == [13, 14]
# Test case 3: Stop on max tokens
scheduler = create_scheduler()
requests = create_requests(num_requests=2, max_tokens=2)
for req in requests:
req.num_computed_tokens = req.num_tokens
scheduler.requests[req.request_id] = req
scheduler.running.append(req)
scheduler.scheduled_req_ids.add(req.request_id)
scheduler_output = SchedulerOutput(scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={
requests[0].request_id: 3,
requests[1].request_id: 1
},
total_num_scheduled_tokens=4,
scheduled_encoder_inputs={},
scheduled_spec_decode_tokens={
requests[0].request_id: [10, 11],
requests[1].request_id: []
},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[])
model_output = ModelRunnerOutput(
req_ids=[req.request_id for req in requests],
req_id_to_index={
req.request_id: i
for i, req in enumerate(requests)
},
sampled_token_ids=[[10, 11, 12],
[13]], # First request exceeds max_tokens
logprobs=None,
prompt_logprobs_dict={})
scheduler.update_from_output(scheduler_output, model_output)
# Verify first request stopped due to length
assert len(scheduler.running) == 1
assert scheduler.running[0].request_id == requests[1].request_id
assert requests[0].status == RequestStatus.FINISHED_LENGTH_CAPPED
assert requests[0].request_id in scheduler.finished_req_ids
assert list(requests[0].output_token_ids) == [10, 11
] # Truncated to max_tokens
assert list(requests[1].output_token_ids) == [13]
# Test case 4: Ignore EOS flag
scheduler = create_scheduler()
requests = create_requests(num_requests=1, max_tokens=10)
requests[0].sampling_params.ignore_eos = True
requests[0].num_computed_tokens = requests[0].num_tokens
scheduler.requests[requests[0].request_id] = requests[0]
scheduler.running.append(requests[0])
scheduler.scheduled_req_ids.add(requests[0].request_id)
scheduler_output = SchedulerOutput(
scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={requests[0].request_id: 3},
total_num_scheduled_tokens=3,
scheduled_encoder_inputs={},
scheduled_spec_decode_tokens={
requests[0].request_id: [EOS_TOKEN_ID, 10]
},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[])
model_output = ModelRunnerOutput(
req_ids=[requests[0].request_id],
req_id_to_index={requests[0].request_id: 0},
sampled_token_ids=[[EOS_TOKEN_ID, 10, 11]],
logprobs=None,
prompt_logprobs_dict={})
scheduler.update_from_output(scheduler_output, model_output)
# Verify request continues past EOS
assert len(scheduler.running) == 1
assert not requests[0].is_finished()
assert list(requests[0].output_token_ids) == [EOS_TOKEN_ID, 10, 11]
def test_schedule_concurrent_batches():
scheduler = create_scheduler(
max_num_batched_tokens=1024,
@@ -243,7 +433,7 @@ def test_schedule_concurrent_batches():
model_runner_output = ModelRunnerOutput(
req_ids=[requests[0].request_id],
req_id_to_index={requests[0].request_id: 0},
sampled_token_ids=[0],
sampled_token_ids=[[0]],
logprobs=None,
prompt_logprobs_dict={},
)
@@ -259,7 +449,7 @@ def test_schedule_concurrent_batches():
model_runner_output = ModelRunnerOutput(
req_ids=[requests[1].request_id],
req_id_to_index={requests[1].request_id: 0},
sampled_token_ids=[0],
sampled_token_ids=[[0]],
logprobs=None,
prompt_logprobs_dict={},
)