vllm/tests/neuron/test_logits_processor.py
2025-03-02 17:34:51 -08:00

95 lines
3.3 KiB
Python

# SPDX-License-Identifier: Apache-2.0
import random
from unittest.mock import patch
import pytest
import torch
from vllm.model_executor.layers.logits_processor import LogitsProcessor
from vllm.model_executor.sampling_metadata import SamplingMetadata
from vllm.model_executor.utils import set_random_seed
from vllm.sequence import SamplingParams, SequenceData, SequenceGroupMetadata
from vllm.utils import is_pin_memory_available
class MockLogitsProcessor(LogitsProcessor):
def __init__(self, vocab_size: int, scale: float,
fake_logits: torch.Tensor):
super().__init__(vocab_size=vocab_size, scale=scale)
self.fake_logits = fake_logits.clone()
def forward(self, *args, **kwargs):
with patch(
"vllm.model_executor.layers.logits_processor._prune_hidden_states",
lambda x, y: x
), patch(
"vllm.model_executor.layers.logits_processor.LogitsProcessor._get_logits",
lambda *args, **kwargs: self.fake_logits):
return super().forward(*args, **kwargs)
def _prepare_test(
batch_size: int
) -> tuple[torch.Tensor, torch.Tensor, MockLogitsProcessor]:
vocab_size = 32000
input_tensor = torch.rand((batch_size, 1024), dtype=torch.float16)
fake_logits = torch.full((batch_size, vocab_size),
1e-2,
dtype=input_tensor.dtype)
logits_processor = MockLogitsProcessor(32000, 0.5, fake_logits)
return input_tensor, fake_logits, logits_processor
RANDOM_SEEDS = list(range(8))
@pytest.mark.parametrize("seed", RANDOM_SEEDS)
def test_logits_processors(seed: int):
import torch_xla.core.xla_model as xm
device = xm.xla_device()
set_random_seed(seed)
torch.set_default_device("cpu")
batch_size = random.randint(1, 256)
input_tensor, fake_logits, logits_processor = _prepare_test(batch_size)
# This sample logits processor gives infinite score to the i-th token,
# where i is the length of the input sequence.
# We therefore expect the output token sequence to be [0, 1, 2, ...]
def pick_ith(token_ids, logits):
logits[len(token_ids)] = float("inf")
return logits
seq_group_metadata_list = []
seq_lens = []
for i in range(batch_size):
seq_group_metadata_list.append(
SequenceGroupMetadata(
request_id=f"test_{i}",
is_prompt=True,
seq_data={0: SequenceData.from_seqs([1, 2, 3])},
sampling_params=SamplingParams(temperature=0,
logits_processors=[pick_ith]),
block_tables={0: [1]},
))
seq_lens.append(seq_group_metadata_list[-1].seq_data[0].get_len())
sampling_metadata = SamplingMetadata.prepare(
seq_group_metadata_list,
seq_lens,
query_lens=seq_lens,
device=device,
pin_memory=is_pin_memory_available())
logits_processor_output = logits_processor(
lm_head=None,
hidden_states=input_tensor,
sampling_metadata=sampling_metadata)
fake_logits *= logits_processor.scale
torch.testing.assert_close(logits_processor_output[:, 1],
fake_logits[:, 1],
rtol=1e-4,
atol=0.0)