[Speculative decoding 6/9] Integrate speculative decoding with LLMEngine (#3894)

This commit is contained in:
Cade Daniel
2024-04-16 13:09:21 -07:00
committed by GitHub
parent 69e1d2fb69
commit e95cd87959
31 changed files with 1347 additions and 407 deletions

View File

@@ -230,6 +230,76 @@ def test_lookahead_greedy_equality_with_preemption(baseline_llm_generator,
assert baseline_token_ids == test_token_ids
@pytest.mark.parametrize(
"common_llm_kwargs",
[
{
# Use a small model for a fast test.
"model": "facebook/opt-125m",
# skip cuda graph creation for fast test.
"enforce_eager": True,
"enable_chunked_prefill": True,
"max_num_batched_tokens": 2,
"max_num_seqs": 2,
},
])
@pytest.mark.parametrize("per_test_common_llm_kwargs", [{}])
@pytest.mark.parametrize("baseline_llm_kwargs", [
{
"use_v2_block_manager": False,
},
])
@pytest.mark.parametrize("test_llm_kwargs", [
{
"use_v2_block_manager": True,
"num_lookahead_slots": 0,
},
{
"use_v2_block_manager": True,
"num_lookahead_slots": 5,
},
])
@pytest.mark.parametrize("batch_size", [4])
@pytest.mark.parametrize("seed", [1])
def test_chunked_prefill_block_manager_v2(baseline_llm_generator,
test_llm_generator, batch_size):
"""Verify that chunked prefill works with BlockManagerV2, with and without
lookahead scheduling.
"""
output_len = 32
temperature = 0.0
prompts = [
"Hello, my name is",
"The president of the United States is",
"The capital of France is",
"The future of AI is",
]
prompts = [prompt for prompt, _ in zip(cycle(prompts), range(batch_size))]
sampling_params = SamplingParams(
max_tokens=output_len,
ignore_eos=True,
temperature=temperature,
)
print('Getting token ids with BlockManagerV1')
baseline_token_ids = get_token_ids_from_llm_generator(
baseline_llm_generator, prompts, sampling_params)
print('Getting token ids with BlockManagerV2')
test_token_ids = get_token_ids_from_llm_generator(test_llm_generator,
prompts, sampling_params)
for expected_token_ids, actual_token_ids in zip(baseline_token_ids,
test_token_ids):
assert expected_token_ids == actual_token_ids
assert baseline_token_ids == test_token_ids
def get_token_ids_from_llm_generator(llm_generator, prompts, sampling_params):
for llm in llm_generator:
outputs = llm.generate(prompts, sampling_params, use_tqdm=True)

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@@ -1,5 +1,5 @@
import time
from typing import Optional, Tuple
from typing import Iterable, Optional, Tuple
from vllm import SamplingParams
from vllm.lora.request import LoRARequest
@@ -31,14 +31,17 @@ def create_dummy_prompt(
def create_seq_group(
seq_prompt_len=1024,
seq_output_lens=(128, ),
request_id='0',
seq_id_start=0,
) -> SequenceGroup:
seq_prompt_len: int = 1024,
seq_output_lens: Iterable[int] = (128, ),
request_id: str = '0',
seq_id_start: int = 0,
sampling_params: Optional[SamplingParams] = None) -> SequenceGroup:
assert len(seq_output_lens) > 0
if sampling_params is None:
sampling_params = SamplingParams()
prompt_token_ids = [0] * seq_prompt_len
seqs = []
@@ -60,7 +63,7 @@ def create_seq_group(
seq_group = SequenceGroup(
request_id=request_id,
seqs=seqs,
sampling_params=SamplingParams(),
sampling_params=sampling_params,
arrival_time=time.time(),
)

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@@ -0,0 +1,270 @@
import random
from unittest.mock import MagicMock
import pytest
from transformers import PreTrainedTokenizer
from tests.core.utils import create_seq_group
from vllm.core.scheduler import Scheduler
from vllm.engine.output_processor.multi_step import MultiStepOutputProcessor
from vllm.engine.output_processor.stop_checker import StopChecker
from vllm.sampling_params import SamplingParams
from vllm.sequence import (Logprob, SequenceGroupOutput, SequenceOutput,
SequenceStatus)
from vllm.transformers_utils.detokenizer import Detokenizer
from vllm.utils import Counter
@pytest.mark.parametrize("seq_output_len", [128])
@pytest.mark.parametrize("num_new_tokens", [1, 12])
@pytest.mark.skip_global_cleanup
def test_appends_token_ids(num_new_tokens: int, seq_output_len: int):
"""Verify multi-step decoding appends token ids correctly.
We append token ids and verify all the token ids were appended correctly.
Note that ignore_eos=True.
"""
detokenizer = MagicMock(spec=Detokenizer)
scheduler = MagicMock(spec=Scheduler)
stop_checker = MagicMock(spec=StopChecker)
seq_counter = Counter()
output_processor = MultiStepOutputProcessor(
detokenizer=detokenizer,
scheduler=scheduler,
seq_counter=seq_counter,
get_tokenizer_for_seq=lambda _: mock_tokenizer(),
stop_checker=stop_checker,
)
seq_group = create_seq_group(
seq_prompt_len=1024,
seq_output_lens=[seq_output_len],
sampling_params=SamplingParams(max_tokens=seq_output_len +
num_new_tokens,
ignore_eos=True),
)
seq = seq_group.get_seqs()[0]
seq.status = SequenceStatus.RUNNING
new_token_ids = list(range(num_new_tokens))
outputs = [
SequenceGroupOutput(
samples=[
SequenceOutput(
parent_seq_id=seq.seq_id,
output_token=output_token,
logprobs={output_token: Logprob(0.0)},
)
],
prompt_logprobs=None,
) for output_token in new_token_ids
]
assert seq.get_token_ids()[-len(new_token_ids):] != new_token_ids
output_processor.process_outputs(seq_group, outputs)
assert seq.get_token_ids()[-len(new_token_ids):] == new_token_ids
@pytest.mark.parametrize("seq_prompt_len", [1024])
@pytest.mark.parametrize("seq_output_len", [128])
@pytest.mark.parametrize("num_new_tokens", [5, 6, 7, 8])
@pytest.mark.parametrize("max_tokens", [128 + 3])
@pytest.mark.skip_global_cleanup
def test_respects_max_tokens(num_new_tokens: int, seq_prompt_len: int,
seq_output_len: int, max_tokens: int):
"""Verify tokens after max_tokens are dropped and not appended to the
sequence.
"""
detokenizer = MagicMock(spec=Detokenizer)
scheduler = MagicMock(spec=Scheduler)
stop_checker = MagicMock(spec=StopChecker)
seq_counter = Counter()
output_processor = MultiStepOutputProcessor(
detokenizer=detokenizer,
scheduler=scheduler,
seq_counter=seq_counter,
get_tokenizer_for_seq=lambda _: mock_tokenizer(),
stop_checker=stop_checker,
)
seq_group = create_seq_group(
seq_prompt_len=seq_prompt_len,
seq_output_lens=[seq_output_len],
sampling_params=SamplingParams(max_tokens=max_tokens, ),
)
seq = seq_group.get_seqs()[0]
seq.status = SequenceStatus.RUNNING
new_token_ids = list(range(num_new_tokens))
outputs = [
SequenceGroupOutput(
samples=[
SequenceOutput(
parent_seq_id=seq.seq_id,
output_token=output_token,
logprobs={output_token: Logprob(0.0)},
)
],
prompt_logprobs=None,
) for output_token in new_token_ids
]
assert seq.get_len() == seq_prompt_len + seq_output_len
output_processor.process_outputs(seq_group, outputs)
# Expect the processed sequence to not go over max tokens in len.
assert seq.get_len() == seq_prompt_len + max_tokens
# Expect the correct tokens were appended.
expected_appended_tokens = new_token_ids[:max_tokens - seq_output_len]
assert seq.get_token_ids(
)[-len(expected_appended_tokens):] == expected_appended_tokens
@pytest.mark.parametrize("seq_prompt_len", [1024])
@pytest.mark.parametrize("seq_output_len", [128])
@pytest.mark.parametrize("num_new_tokens", [12])
@pytest.mark.parametrize("seed", list(range(6)))
@pytest.mark.skip_global_cleanup
def test_respects_eos_token_id(num_new_tokens: int, seq_prompt_len: int,
seq_output_len: int, seed: int):
"""Verify the eos token id is included in the sequence, but subsequent
tokens are dropped (not appended to sequence).
"""
random.seed(seed)
detokenizer = MagicMock(spec=Detokenizer)
scheduler = MagicMock(spec=Scheduler)
stop_checker = MagicMock(spec=StopChecker)
seq_counter = Counter()
eos_token_id = 100
output_processor = MultiStepOutputProcessor(
detokenizer=detokenizer,
scheduler=scheduler,
seq_counter=seq_counter,
get_tokenizer_for_seq=lambda _: mock_tokenizer(eos_token_id),
stop_checker=stop_checker,
)
seq_group = create_seq_group(
seq_prompt_len=seq_prompt_len,
seq_output_lens=[seq_output_len],
sampling_params=SamplingParams(
# Ensure enough space.
max_tokens=seq_output_len + num_new_tokens, ),
)
seq = seq_group.get_seqs()[0]
seq.status = SequenceStatus.RUNNING
new_token_ids = list(range(num_new_tokens))
assert eos_token_id not in new_token_ids
eos_index = random.randint(0, len(new_token_ids) - 1)
new_token_ids[eos_index] = eos_token_id
outputs = [
SequenceGroupOutput(
samples=[
SequenceOutput(
parent_seq_id=seq.seq_id,
output_token=output_token,
logprobs={output_token: Logprob(0.0)},
)
],
prompt_logprobs=None,
) for output_token in new_token_ids
]
assert seq.get_len() == seq_prompt_len + seq_output_len
output_processor.process_outputs(seq_group, outputs)
# Expect the processed sequence to not go beyond provided eos.
assert seq.get_len() == seq_prompt_len + seq_output_len + (eos_index + 1)
# Expect the correct tokens were appended.
expected_appended_tokens = new_token_ids[:eos_index + 1]
assert seq.get_token_ids(
)[-len(expected_appended_tokens):] == expected_appended_tokens
@pytest.mark.parametrize("seq_prompt_len", [1024])
@pytest.mark.parametrize("seq_output_len", [128])
@pytest.mark.parametrize("num_new_tokens", [12])
@pytest.mark.parametrize("seed", list(range(6)))
@pytest.mark.skip_global_cleanup
def test_ignores_eos_token_id(num_new_tokens: int, seq_prompt_len: int,
seq_output_len: int, seed: int):
"""When sampling parameters dictate that we should ignore the eos token id,
ensure all token ids are appended even if the eos token id is emitted.
"""
random.seed(seed)
detokenizer = MagicMock(spec=Detokenizer)
scheduler = MagicMock(spec=Scheduler)
stop_checker = MagicMock(spec=StopChecker)
seq_counter = Counter()
eos_token_id = 100
output_processor = MultiStepOutputProcessor(
detokenizer=detokenizer,
scheduler=scheduler,
seq_counter=seq_counter,
get_tokenizer_for_seq=lambda _: mock_tokenizer(eos_token_id),
stop_checker=stop_checker,
)
seq_group = create_seq_group(
seq_prompt_len=seq_prompt_len,
seq_output_lens=[seq_output_len],
sampling_params=SamplingParams(
# Ensure enough space.
max_tokens=seq_output_len + num_new_tokens,
ignore_eos=True,
),
)
seq = seq_group.get_seqs()[0]
seq.status = SequenceStatus.RUNNING
new_token_ids = list(range(num_new_tokens))
assert eos_token_id not in new_token_ids
eos_index = random.randint(0, len(new_token_ids) - 1)
new_token_ids[eos_index] = eos_token_id
outputs = [
SequenceGroupOutput(
samples=[
SequenceOutput(
parent_seq_id=seq.seq_id,
output_token=output_token,
logprobs={output_token: Logprob(0.0)},
)
],
prompt_logprobs=None,
) for output_token in new_token_ids
]
assert seq.get_len() == seq_prompt_len + seq_output_len
output_processor.process_outputs(seq_group, outputs)
# Expect the processed sequence to go beyond eos.
assert seq.get_len() == seq_prompt_len + seq_output_len + num_new_tokens
# Expect the correct tokens were appended.
expected_appended_tokens = new_token_ids[:seq_output_len + num_new_tokens -
seq_output_len]
assert seq.get_token_ids(
)[-len(expected_appended_tokens):] == expected_appended_tokens
def mock_tokenizer(eos_token_id=1000):
tokenizer = MagicMock(spec=PreTrainedTokenizer)
tokenizer.eos_token_id = eos_token_id
return tokenizer

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@@ -1,4 +1,8 @@
from itertools import cycle
from typing import List, Tuple
import pytest
from transformers import AutoTokenizer
from vllm import SamplingParams
@@ -7,18 +11,47 @@ from vllm import SamplingParams
"common_llm_kwargs",
[{
# Use a small model for a fast test.
"model": "facebook/opt-125m",
"speculative_model": "facebook/opt-125m",
"num_speculative_tokens": 5,
# Note this is repeated in the test body; to initialize a tokenizer.
"model": "JackFram/llama-68m",
# Skip real loading for fast test.
"load_format": "dummy",
# Skip cuda graph recording for fast test.
"enforce_eager": True,
# Required for spec decode.
"use_v2_block_manager": True
}])
@pytest.mark.parametrize("per_test_common_llm_kwargs", [{}])
@pytest.mark.parametrize(
"per_test_common_llm_kwargs",
[
{
"speculative_model": "JackFram/llama-68m",
"num_speculative_tokens": 5,
},
{
"speculative_model": "JackFram/llama-68m",
"num_speculative_tokens": 1,
},
{
# No spec decode.
},
])
@pytest.mark.parametrize("test_llm_kwargs", [{}])
@pytest.mark.parametrize("batch_size", [1])
# NOTE: We should run more permutations of this test (more BS, more seeds). But
# because our spec decode generates gibberish token ids, the likelihood of
# emitting an invalid token combination is nontrivial. This causes divergence in
# behavior of vLLM detokenization vs. hf tokenizer, for example when two "utf-
# start" bytes are emitted.
@pytest.mark.parametrize("seed", [1])
def test_spec_decode_config(test_llm_generator):
output_len = 1024
def test_spec_decode_e2e_logical_flow(test_llm_generator, batch_size: int):
"""Run generation with speculative decoding on a batch. Verify the engine
generates the correct number of tokens (via ignore_eos=True), and that the
detokenization matches HF transformers.
"""
output_len = 32
temperature = 0.0
prompts = [
@@ -28,23 +61,91 @@ def test_spec_decode_config(test_llm_generator):
"The future of AI is",
]
prompts = [prompt for prompt, _ in zip(cycle(prompts), range(batch_size))]
sampling_params = SamplingParams(
max_tokens=output_len,
ignore_eos=True,
temperature=temperature,
skip_special_tokens=True,
spaces_between_special_tokens=False,
)
batch_tokens, batch_token_ids = get_output_from_llm_generator(
test_llm_generator, prompts, sampling_params)
# Expect a generation for each prompt in the batch.
assert len(batch_token_ids) == len(prompts)
# Expect each generation to have expected number of tokens (note
# ignore_eos=True).
assert all(len(token_ids) == output_len for token_ids in batch_token_ids)
# Expect detokenized string to match.
tok = AutoTokenizer.from_pretrained("JackFram/llama-68m")
for actual_tokens, actual_token_ids in zip(batch_tokens, batch_token_ids):
expected_tokens = tok.decode(actual_token_ids)
print(f"{actual_token_ids=}")
assert actual_tokens.strip() == expected_tokens.strip()
@pytest.mark.parametrize(
"common_llm_kwargs",
[{
# Use a small model for a fast test.
"model": "JackFram/llama-68m",
"speculative_model": "JackFram/llama-68m",
"num_speculative_tokens": 5,
# Skip real loading for fast test.
"load_format": "dummy",
# Skip cuda graph recording for fast test.
"enforce_eager": True,
# Required for spec decode.
"use_v2_block_manager": True
}])
@pytest.mark.parametrize(
"per_test_common_llm_kwargs",
[
{
# Expect failure as spec decode not supported by
# Ray backend.
"worker_use_ray": True,
},
])
@pytest.mark.parametrize("test_llm_kwargs", [{}])
@pytest.mark.parametrize("seed", [1])
def test_spec_decode_xfail(test_llm_generator):
"""Verify that speculative decoding with Ray fails.
"""
output_len = 128
temperature = 0.0
prompts = [
"Hello, my name is",
]
sampling_params = SamplingParams(
max_tokens=output_len,
ignore_eos=True,
temperature=temperature,
)
with pytest.raises(
AssertionError,
match="Speculative decoding not yet supported for GPU backend"):
get_token_ids_from_llm_generator(test_llm_generator, prompts,
sampling_params)
with pytest.raises(AssertionError,
match="Speculative decoding not yet supported for "):
get_output_from_llm_generator(test_llm_generator, prompts,
sampling_params)
def get_token_ids_from_llm_generator(llm_generator, prompts, sampling_params):
def get_output_from_llm_generator(
llm_generator, prompts,
sampling_params) -> Tuple[List[str], List[List[int]]]:
for llm in llm_generator:
outputs = llm.generate(prompts, sampling_params, use_tqdm=True)
token_ids = [output.outputs[0].token_ids for output in outputs]
tokens = [output.outputs[0].text for output in outputs]
del llm
return token_ids
return tokens, token_ids

View File

@@ -125,7 +125,7 @@ def test_same_output_for_single_step():
zero_kv_cache(worker.cache_engine)
set_random_seed(seed)
expected_output = worker.execute_model(
**single_step_execute_model_data.to_dict(), )
**single_step_execute_model_data.to_dict(), )[0]
actual_token_ids = [
output.samples[0].output_token for output in actual_output
@@ -219,7 +219,7 @@ def test_same_output_for_multi_step():
continuations=continuations,
final_seq_lens=final_seq_lens))
single_step_output.append(
single_step_output.extend(
worker.execute_model(**execute_model_data.to_dict(), ))
# Append output tokens to new sequence data.

View File

@@ -6,6 +6,7 @@ import torch
from vllm.model_executor.layers.rejection_sampler import RejectionSampler
from vllm.model_executor.utils import set_random_seed
from vllm.sequence import SamplerOutput
from vllm.spec_decode.interfaces import SpeculativeProposals
from vllm.spec_decode.metrics import (AsyncMetricsCollector,
SpecDecodeWorkerMetrics)
@@ -37,7 +38,8 @@ def test_correctly_calls_draft_model(k: int, batch_size: int):
execute_model_data, _, _ = create_batch(batch_size, k)
with pytest.raises(ValueError, match=exception_secret):
worker.execute_model(**execute_model_data.to_dict(), num_spec_tokens=k)
worker.execute_model(**execute_model_data.to_dict(),
num_lookahead_slots=k)
call_args_list = draft_worker.get_spec_proposals.call_args_list
assert len(call_args_list) == 1
@@ -102,7 +104,8 @@ def test_correctly_calls_target_model(k: int, batch_size: int):
target_worker.execute_model.side_effect = ValueError(exception_secret)
with pytest.raises(ValueError, match=exception_secret):
worker.execute_model(**execute_model_data.to_dict(), num_spec_tokens=k)
worker.execute_model(**execute_model_data.to_dict(),
num_lookahead_slots=k)
seen_contexts = []
@@ -189,13 +192,14 @@ def test_correctly_calls_rejection_sampler(k: int, batch_size: int):
target_output = create_sampler_output_list(target_token_ids,
target_token_probs)
target_worker.execute_model.return_value = target_output[0]
target_worker.execute_model.return_value = [target_output[0]]
exception_secret = 'artifical stop'
rejection_sampler.side_effect = ValueError(exception_secret)
with pytest.raises(ValueError, match=exception_secret):
worker.execute_model(**execute_model_data.to_dict(), num_spec_tokens=k)
worker.execute_model(**execute_model_data.to_dict(),
num_lookahead_slots=k)
assert len(rejection_sampler.call_args_list) == 1
args, _ = rejection_sampler.call_args_list[0]
@@ -268,7 +272,7 @@ def test_correctly_formats_output(k: int, batch_size: int):
target_output = create_sampler_output_list(target_token_ids,
target_token_probs)
target_worker.execute_model.return_value = target_output[0]
target_worker.execute_model.return_value = [target_output[0]]
rejection_sampler_output = torch.randint(low=0,
high=vocab_size,
@@ -283,7 +287,7 @@ def test_correctly_formats_output(k: int, batch_size: int):
rejection_sampler.return_value = rejection_sampler_output
output = worker.execute_model(**execute_model_data.to_dict(),
num_spec_tokens=k)
num_lookahead_slots=k)
expected_output = create_sampler_output_list(
rejection_sampler_output.transpose(0, 1), [None for _ in range(k + 1)])
@@ -380,7 +384,7 @@ def test_collects_metrics(k: int, batch_size: int, returns_metrics: bool):
target_output = create_sampler_output_list(target_token_ids,
target_token_probs)
target_worker.execute_model.return_value = target_output[0]
target_worker.execute_model.return_value = [target_output[0]]
rejection_sampler_output = torch.randint(low=0,
high=vocab_size,
@@ -400,7 +404,7 @@ def test_collects_metrics(k: int, batch_size: int, returns_metrics: bool):
mock_rejsample_metrics)
output = worker.execute_model(**execute_model_data.to_dict(),
num_spec_tokens=k)
num_lookahead_slots=k)
assert output[0].spec_decode_worker_metrics == mock_rejsample_metrics
call_args_list = (
@@ -423,6 +427,8 @@ def test_k_equals_zero(k: int, batch_size: int):
rejection_sampler.token_id_dtype = torch.int64
metrics_collector = MagicMock(spec=AsyncMetricsCollector)
target_worker.execute_model.return_value = [MagicMock(spec=SamplerOutput)]
draft_worker.device = 'cuda'
target_worker.device = 'cuda'
@@ -435,7 +441,7 @@ def test_k_equals_zero(k: int, batch_size: int):
batch_size, k, prev_output_token_len=0)
out = worker.execute_model(**execute_model_data.to_dict(),
num_spec_tokens=k)
num_lookahead_slots=k)
assert len(out) == 1, f"expected only one token output when {k=}"
assert out[0].probs is None, "expect gpu tensor references to be None"
@@ -443,7 +449,7 @@ def test_k_equals_zero(k: int, batch_size: int):
0].sampled_tokens is None, "expect gpu tensor references to be None"
draft_worker.execute_model.assert_called_once_with(
**execute_model_data.to_dict(), return_python_output=False)
**execute_model_data.to_dict())
target_worker.execute_model.assert_called_once_with(
**execute_model_data.to_dict())
@@ -462,6 +468,8 @@ def test_empty_input_batch(k: int, batch_size: int):
rejection_sampler.token_id_dtype = torch.int64
metrics_collector = MagicMock(spec=AsyncMetricsCollector)
target_worker.execute_model.return_value = [MagicMock(spec=SamplerOutput)]
draft_worker.device = 'cuda'
target_worker.device = 'cuda'
@@ -474,7 +482,7 @@ def test_empty_input_batch(k: int, batch_size: int):
batch_size, k, prev_output_token_len=0)
out = worker.execute_model(**execute_model_data.to_dict(),
num_spec_tokens=k)
num_lookahead_slots=k)
assert len(out) == 1, f"expected only one token output when {k=}"
assert out[0].probs is None, "expect gpu tensor references to be None"
@@ -482,7 +490,7 @@ def test_empty_input_batch(k: int, batch_size: int):
0].sampled_tokens is None, "expect gpu tensor references to be None"
draft_worker.execute_model.assert_called_once_with(
**execute_model_data.to_dict(), return_python_output=False)
**execute_model_data.to_dict())
target_worker.execute_model.assert_called_once_with(
**execute_model_data.to_dict())

View File

@@ -212,7 +212,7 @@ def create_sampler_output_list(
SequenceOutput(
output_token=token_id,
parent_seq_id=seq_ids[seq_index],
logprobs={token_id: 0},
logprobs={token_id: Logprob(0)},
)
],
prompt_logprobs=None,