vllm/tests/v1/sample/test_sampler.py
Russell Bryant e489ad7a21
[Misc] Add SPDX-License-Identifier headers to python source files (#12628)
- **Add SPDX license headers to python source files**
- **Check for SPDX headers using pre-commit**

commit 9d7ef44c3cfb72ca4c32e1c677d99259d10d4745
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:18:24 2025 -0500

    Add SPDX license headers to python source files
    
This commit adds SPDX license headers to python source files as
recommended to
the project by the Linux Foundation. These headers provide a concise way
that is
both human and machine readable for communicating license information
for each
source file. It helps avoid any ambiguity about the license of the code
and can
    also be easily used by tools to help manage license compliance.
    
The Linux Foundation runs license scans against the codebase to help
ensure
    we are in compliance with the licenses of the code we use, including
dependencies. Having these headers in place helps that tool do its job.
    
    More information can be found on the SPDX site:
    
    - https://spdx.dev/learn/handling-license-info/
    
    Signed-off-by: Russell Bryant <rbryant@redhat.com>

commit 5a1cf1cb3b80759131c73f6a9dddebccac039dea
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:36:32 2025 -0500

    Check for SPDX headers using pre-commit
    
    Signed-off-by: Russell Bryant <rbryant@redhat.com>

---------

Signed-off-by: Russell Bryant <rbryant@redhat.com>
2025-02-02 11:58:18 -08:00

324 lines
14 KiB
Python

# SPDX-License-Identifier: Apache-2.0
from typing import List, Set, Tuple
import numpy as np
import pytest
import torch
from vllm.utils import make_tensor_with_pad
from vllm.v1.sample.metadata import SamplingMetadata
from vllm.v1.sample.sampler import Sampler
VOCAB_SIZE = 1024
NUM_OUTPUT_TOKENS = 20
CUDA_DEVICES = [
f"cuda:{i}" for i in range(1 if torch.cuda.device_count() == 1 else 2)
]
MAX_NUM_PROMPT_TOKENS = 64
def _create_fake_logits(batch_size: int, vocab_size: int) -> torch.Tensor:
fake_logits = torch.full((batch_size, vocab_size), 1e-2, dtype=torch.float)
return fake_logits
def _create_penalty_tensor(batch_size: int, penalty_value: float,
device: torch.device) -> torch.Tensor:
return torch.full((batch_size, ),
fill_value=penalty_value,
dtype=torch.float,
device=device)
def _create_prompt_tokens_tensor(
prompt_token_ids: List[List[int]],
vocab_size: int,
device: torch.device,
) -> torch.Tensor:
return make_tensor_with_pad(
prompt_token_ids,
pad=vocab_size,
device=device,
dtype=torch.int64,
pin_memory=False,
)
def _create_default_sampling_metadata(
num_output_tokens: int,
batch_size: int,
vocab_size: int,
device: torch.device,
) -> SamplingMetadata:
output_token_ids: List[List[int]] = []
prompt_token_ids: List[List[int]] = []
for _ in range(batch_size):
output_token_ids.append(
np.random.randint(0, vocab_size, size=num_output_tokens).tolist())
prompt_token_ids.append(
np.random.randint(0,
vocab_size,
size=np.random.randint(
1, MAX_NUM_PROMPT_TOKENS)).tolist())
fake_sampling_metadata = SamplingMetadata(
temperature=torch.full((batch_size, ), 0.0),
all_greedy=True,
all_random=False,
top_p=torch.empty(batch_size, ),
top_k=torch.empty(batch_size, ),
no_top_p=True,
no_top_k=True,
generators={},
max_num_logprobs=0,
prompt_token_ids=_create_prompt_tokens_tensor(prompt_token_ids,
vocab_size, device),
output_token_ids=output_token_ids,
frequency_penalties=_create_penalty_tensor(batch_size, 0.0, device),
presence_penalties=_create_penalty_tensor(batch_size, 0.0, device),
repetition_penalties=_create_penalty_tensor(batch_size, 1.0, device),
no_penalties=True,
min_tokens=[],
stop_token_ids=[],
)
return fake_sampling_metadata
def _generate_min_token_penalties_and_stop_tokens(
num_output_tokens: int, batch_size: int, vocab_size: int,
batch_indices_for_min_token_penalty: List[int]
) -> Tuple[List[int], List[Set[int]]]:
"""
Generates and returns a list of minimum token penalties (`min_tokens`)
and a corresponding list of stop token IDs (`stop_token_ids`) for each
batch.
If a batch index is included in `batch_indices_for_min_token_penalty`,
a higher `min_tokens` value is assigned (within a randomized range),
and a random set of stop token IDs is created. Otherwise, a lower
`min_tokens` value is assigned, and the stop token IDs set is empty.
"""
stop_token_ids: List[Set[int]] = []
min_tokens: List[int] = []
for index in range(batch_size):
if index in batch_indices_for_min_token_penalty:
min_tokens.append(
np.random.randint(num_output_tokens + 1,
2 * num_output_tokens))
stop_token_ids.append(
set(
np.random.randint(0, vocab_size - 1)
for _ in range(np.random.randint(0, vocab_size))))
else:
min_tokens.append(np.random.randint(0, num_output_tokens))
stop_token_ids.append(set())
return (min_tokens, stop_token_ids)
def _create_weighted_output_token_list(
batch_size: int,
vocab_size: int) -> Tuple[List[List[int]], List[List[int]]]:
"""
Creates an output token list where each token occurs a distinct
number of times.
For each batch, a random subset of token IDs is selected from the
vocabulary. The selected tokens are then added to the output token
list, each with a different frequency.
Returns:
Tuple[List[List[int]], List[List[int]]]:
- The first element is the output token list, where each sublist
corresponds to a batch and contains tokens with weighted
frequencies.
- The second element is a list of distinct token IDs for each
batch, ordered by their frequency in the corresponding output
list.
"""
output_token_ids: List[List[int]] = []
sorted_token_ids_in_output: List[List[int]] = []
for _ in range(batch_size):
distinct_token_ids = np.random.choice(vocab_size,
size=np.random.randint(1, 10),
replace=False).tolist()
sorted_token_ids_in_output.append(distinct_token_ids)
output_token_ids_for_batch = []
for index, token_id in enumerate(distinct_token_ids):
output_token_ids_for_batch.extend(
[token_id for _ in range(index + 1)])
output_token_ids.append(output_token_ids_for_batch)
return (output_token_ids, sorted_token_ids_in_output)
@pytest.mark.parametrize("device", CUDA_DEVICES)
@pytest.mark.parametrize("batch_size", [1, 2, 32])
def test_sampler_min_tokens_penalty(device: str, batch_size: int):
"""
Tests that if the number of output tokens is less than
SamplingParams.min_tokens then we will set the logits for
the stop token ids to -inf.
"""
torch.set_default_device(device)
fake_logits = _create_fake_logits(batch_size, VOCAB_SIZE)
sampling_metadata = _create_default_sampling_metadata(
NUM_OUTPUT_TOKENS, batch_size, VOCAB_SIZE, torch.device(device))
batch_indices_for_min_token_penalty = np.random.randint(
0, batch_size - 1, size=np.random.randint(0, batch_size)).tolist()
min_tokens, stop_token_ids = _generate_min_token_penalties_and_stop_tokens(
NUM_OUTPUT_TOKENS, batch_size, VOCAB_SIZE,
batch_indices_for_min_token_penalty)
sampling_metadata.min_tokens = min_tokens
sampling_metadata.stop_token_ids = stop_token_ids
sampler = Sampler()
logits = sampler.apply_penalties(fake_logits, sampling_metadata)
logits = logits.cpu()
for batch_idx in range(batch_size):
for token_id in range(VOCAB_SIZE):
if token_id in stop_token_ids[batch_idx]:
assert logits[batch_idx][token_id] == -float("inf")
else:
assert logits[batch_idx][token_id] != -float("inf")
@pytest.mark.parametrize("device", CUDA_DEVICES)
@pytest.mark.parametrize("batch_size", [1, 2, 32])
@pytest.mark.parametrize("presence_penalty", [-2.0, 2.0])
def test_sampler_presence_penalty(device: str, batch_size: int,
presence_penalty: float):
"""
Test to verify that if presence penalty is enabled then tokens
are penalized as per their presence in the existing output.
"""
torch.set_default_device(device)
# Create fake logits where each token is assigned the same
# logit value.
fake_logits = _create_fake_logits(batch_size, VOCAB_SIZE)
sampling_metadata = _create_default_sampling_metadata(
NUM_OUTPUT_TOKENS, batch_size, VOCAB_SIZE, torch.device(device))
output_token_ids = sampling_metadata.output_token_ids
sampling_metadata.presence_penalties = _create_penalty_tensor(
batch_size, presence_penalty, torch.device(device))
sampling_metadata.no_penalties = False
sampler = Sampler()
logits = sampler.apply_penalties(fake_logits, sampling_metadata)
logits = logits.cpu()
for batch_idx in range(batch_size):
# Since all tokens initially have the same logits, the non-penalized
# token ID will be the one with the highest logit value, while the
# penalized token ID will be the one with the lowest logit value.
non_penalized_token_id = logits[batch_idx].argmax().item()
penalized_token_id = logits[batch_idx].argmin().item()
if presence_penalty > 0:
# If `presence_penalty` is set to a value greater than 0, it
# indicates a preference for new tokens over those already
# present in the output.
# Verify that the penalized token ID exists in the output, while the
# non-penalized token ID does not.
assert penalized_token_id in output_token_ids[batch_idx]
assert non_penalized_token_id not in output_token_ids[batch_idx]
elif presence_penalty < 0:
# If `presence_penalty` is set to a value less than 0, it indicates
# a preference for existing tokens over new ones. Verify that the
# non-penalized token ID exists in the output, while the penalized
# token ID does not.
assert non_penalized_token_id in output_token_ids[batch_idx]
assert penalized_token_id not in output_token_ids[batch_idx]
@pytest.mark.parametrize("device", CUDA_DEVICES)
@pytest.mark.parametrize("batch_size", [1, 2, 32])
@pytest.mark.parametrize("frequency_penalty", [-2.0, 2.0])
def test_sampler_frequency_penalty(device: str, batch_size: int,
frequency_penalty: float):
"""
Test to verify that if frequency penalty is enabled then tokens are
penalized as per their frequency of occurrence.
"""
torch.set_default_device(device)
# Create fake logits where each token is assigned the same
# logit value.
fake_logits = _create_fake_logits(batch_size, VOCAB_SIZE)
sampling_metadata = _create_default_sampling_metadata(
NUM_OUTPUT_TOKENS, batch_size, VOCAB_SIZE, torch.device(device))
sampling_metadata.frequency_penalties = _create_penalty_tensor(
batch_size, frequency_penalty, torch.device(device))
output_token_ids, sorted_token_ids_in_output = \
_create_weighted_output_token_list(batch_size, VOCAB_SIZE)
sampling_metadata.output_token_ids = output_token_ids
sampling_metadata.no_penalties = False
sampler = Sampler()
logits = sampler.apply_penalties(fake_logits, sampling_metadata)
logits = logits.cpu()
for batch_idx in range(batch_size):
non_penalized_token_id = logits[batch_idx].argmax().item()
penalized_token_id = logits[batch_idx].argmin().item()
distinct_sorted_token_ids_in_output = \
sorted_token_ids_in_output[batch_idx]
most_frequent_token_id = distinct_sorted_token_ids_in_output[
len(distinct_sorted_token_ids_in_output) - 1]
if frequency_penalty > 0:
# If `frequency_penalty` is set to > 0, it indicates
# a preference for new tokens over existing ones. Verify that the
# non-penalized token ID is not present in the output, while the
# most penalized token is the one that occurs most frequently in
# the output.
assert non_penalized_token_id \
not in distinct_sorted_token_ids_in_output
assert penalized_token_id == most_frequent_token_id
elif frequency_penalty < 0:
# If `frequency_penalty` is set to < 0, it indicates
# a preference for existing tokens over new ones. Verify that the
# non-penalized token ID is the one that occurs most frequently
# in the output, while the penalized token ID is one that has not
# yet appeared.
assert non_penalized_token_id == most_frequent_token_id
assert penalized_token_id \
not in distinct_sorted_token_ids_in_output
@pytest.mark.parametrize("device", CUDA_DEVICES)
@pytest.mark.parametrize("batch_size", [1, 2, 32])
@pytest.mark.parametrize("repetition_penalty", [0.1, 1.9])
def test_sampler_repetition_penalty(device: str, batch_size: int,
repetition_penalty: float):
"""
Test to verify that when the repetition penalty is enabled, tokens
are penalized based on their presence in the prompt or the existing
output.
"""
torch.set_default_device(device)
# Create fake logits where each token is assigned the same
# logit value.
fake_logits = _create_fake_logits(batch_size, VOCAB_SIZE)
sampling_metadata = _create_default_sampling_metadata(
NUM_OUTPUT_TOKENS, batch_size, VOCAB_SIZE, torch.device(device))
sampling_metadata.repetition_penalties = _create_penalty_tensor(
batch_size, repetition_penalty, torch.device(device))
sampling_metadata.no_penalties = False
sampler = Sampler()
logits = sampler.apply_penalties(fake_logits, sampling_metadata)
logits = logits.cpu()
for batch_idx in range(batch_size):
non_penalized_token_id = logits[batch_idx].argmax().item()
penalized_token_id = logits[batch_idx].argmin().item()
prompt_tokens = sampling_metadata.prompt_token_ids[
batch_idx][:].tolist()
output_tokens = sampling_metadata.output_token_ids[batch_idx]
if repetition_penalty > 1.0:
# If `repetition_penalty` > 1.0, verify that the non-penalized
# token ID has not been seen before, while the penalized token ID
# exists either in the prompt or the output.
assert (non_penalized_token_id not in prompt_tokens and \
non_penalized_token_id not in output_tokens)
assert (penalized_token_id in prompt_tokens or \
penalized_token_id in output_tokens)
elif repetition_penalty < 1.0:
# If `repetition_penalty` < 1.0, verify that the penalized
# token ID has not been seen before, while the non-penalized
# token ID exists either in the prompt or the output.
assert (penalized_token_id not in prompt_tokens and \
penalized_token_id not in output_tokens)
assert (non_penalized_token_id in prompt_tokens or \
non_penalized_token_id in output_tokens)