vllm/tests/kernels/attention/test_flashinfer_trtllm_attention.py
Michael Goin 0fe85087a9
[CI Perf] Prune tests in tests/kernels/attention/ (#22936)
Signed-off-by: mgoin <mgoin64@gmail.com>
2025-08-14 21:34:53 -06:00

294 lines
10 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from typing import Optional
import flashinfer
import pytest
import torch
from vllm.platforms import current_platform
if not current_platform.is_device_capability(100):
pytest.skip("This TRTLLM kernel requires NVIDIA Blackwell.",
allow_module_level=True)
FLOAT32_BYTES = torch.finfo(torch.float).bits // 8
# KV Cache Layout for TRT-LLM
# kv_cache_shape = (num_blocks, 2, num_kv_heads, page_size, head_dim)
MAX_Q_LEN = 1024
MAX_KV_LEN = 4096
BATCH_SIZES = [4, 12]
NUM_HEADS = [(16, 16), (40, 8)]
HEAD_SIZES = [128]
BLOCK_SIZES = [16]
KV_LAYOUTS = ["HND"]
DTYPES = [torch.bfloat16]
KV_CACHE_DTYPES = [None, current_platform.fp8_dtype()]
NUM_BLOCKS = 32768 # Large enough to test overflow in index calculation.
SOFT_CAPS = [None, 50.0]
def to_float8(x, dtype=torch.float8_e4m3fn):
finfo = torch.finfo(dtype)
min_val, max_val = x.aminmax()
amax = torch.maximum(min_val.abs(), max_val.abs()).clamp(min=1e-12)
scale = finfo.max / amax * 0.1
x_scl_sat = (x * scale).clamp(min=finfo.min, max=finfo.max)
return x_scl_sat.to(dtype), scale.float().reciprocal()
@pytest.mark.parametrize("batch_size", BATCH_SIZES)
@pytest.mark.parametrize("num_heads", NUM_HEADS)
@pytest.mark.parametrize("head_size", HEAD_SIZES)
@pytest.mark.parametrize("block_size", BLOCK_SIZES)
@pytest.mark.parametrize("kv_layout", KV_LAYOUTS)
@pytest.mark.parametrize("dtype", DTYPES)
@pytest.mark.parametrize("kv_cache_dtype", KV_CACHE_DTYPES)
@pytest.mark.parametrize("soft_cap", SOFT_CAPS)
@torch.inference_mode
def test_flashinfer_trtllm_decode_with_baseline(
batch_size: int,
num_heads: tuple[int, int],
head_size: int,
block_size: int,
kv_layout: str,
dtype: torch.dtype,
kv_cache_dtype: Optional[torch.dtype],
soft_cap: Optional[float],
) -> None:
kv_cache_dtype = dtype if kv_cache_dtype is None else kv_cache_dtype
torch.set_default_device("cuda")
current_platform.seed_everything(0)
kv_lens = torch.randint(1, MAX_KV_LEN, (batch_size, ), dtype=torch.int32)
kv_lens[-1] = MAX_KV_LEN
max_kv_len = torch.max(kv_lens).item()
num_seqs = len(kv_lens)
num_query_heads = num_heads[0]
num_kv_heads = num_heads[1]
assert num_query_heads % num_kv_heads == 0
scale = head_size**-0.5
query = torch.randn(num_seqs, num_query_heads, head_size, dtype=dtype)
kv_cache_shape = None
if kv_layout == "NHD":
kv_cache_shape = (NUM_BLOCKS, 2, block_size, num_kv_heads, head_size)
elif kv_layout == "HND":
kv_cache_shape = (NUM_BLOCKS, 2, num_kv_heads, block_size, head_size)
else:
raise ValueError(f"Invalid kv_layout: {kv_layout}")
key_value_cache = torch.randn(kv_cache_shape, dtype=dtype)
kv_scale = 1.0
if kv_cache_dtype is current_platform.fp8_dtype():
key_value_cache, kv_scale = to_float8(key_value_cache,
current_platform.fp8_dtype())
max_num_blocks_per_seq = (max_kv_len + block_size - 1) // block_size
block_tables = torch.randint(0,
NUM_BLOCKS,
(num_seqs, max_num_blocks_per_seq),
dtype=torch.int32)
k_scale = v_scale = kv_scale
kv_indptr = [0]
kv_indices = []
kv_last_page_lens = []
for i in range(num_seqs):
seq_len = kv_lens[i]
assert seq_len > 0
num_blocks = (seq_len + block_size - 1) // block_size
kv_indices.extend(block_tables[i, :num_blocks])
kv_indptr.append(kv_indptr[-1] + num_blocks)
kv_last_page_len = seq_len % block_size
if kv_last_page_len == 0:
kv_last_page_len = block_size
kv_last_page_lens.append(kv_last_page_len)
kv_indptr = torch.tensor(kv_indptr, dtype=torch.int32)
kv_indices = torch.tensor(kv_indices, dtype=torch.int32)
kv_last_page_lens = torch.tensor(kv_last_page_lens, dtype=torch.int32)
workspace_buffer = torch.empty(128 * 1024 * 1024, dtype=torch.int8)
wrapper = flashinfer.BatchDecodeWithPagedKVCacheWrapper(
workspace_buffer,
kv_layout,
use_tensor_cores=((num_query_heads // num_kv_heads) > 4))
wrapper.plan(kv_indptr,
kv_indices,
kv_last_page_lens,
num_query_heads,
num_kv_heads,
head_size,
block_size,
"NONE",
sm_scale=scale,
q_data_type=dtype,
kv_data_type=kv_cache_dtype,
logits_soft_cap=soft_cap)
output = torch.empty(query.shape, dtype=dtype)
wrapper.run(query,
key_value_cache,
k_scale=k_scale,
v_scale=v_scale,
out=output)
# TRTLLM Decode
kv_lens_tensor = torch.tensor(kv_lens, dtype=torch.int32)
output_trtllm = torch.empty(query.shape, dtype=dtype)
flashinfer.decode.trtllm_batch_decode_with_kv_cache(
query=query.contiguous(),
kv_cache=key_value_cache,
workspace_buffer=workspace_buffer,
block_tables=block_tables,
seq_lens=kv_lens_tensor,
max_seq_len=max_kv_len,
bmm1_scale=k_scale * scale,
bmm2_scale=v_scale,
out=output_trtllm,
)
torch.testing.assert_close(output, output_trtllm, atol=1e-2, rtol=1e-2), \
f"{torch.max(torch.abs(output - output_trtllm))}"
@pytest.mark.parametrize("batch_size", BATCH_SIZES)
@pytest.mark.parametrize("num_heads", NUM_HEADS)
@pytest.mark.parametrize("head_size", HEAD_SIZES)
@pytest.mark.parametrize("block_size", BLOCK_SIZES)
@pytest.mark.parametrize("kv_layout", KV_LAYOUTS)
@pytest.mark.parametrize("dtype", DTYPES)
@pytest.mark.parametrize("kv_cache_dtype", KV_CACHE_DTYPES)
@pytest.mark.parametrize("soft_cap", [None])
@torch.inference_mode
def test_flashinfer_trtllm_prefill_with_baseline(
batch_size: int,
num_heads: tuple[int, int],
head_size: int,
block_size: int,
kv_layout: str,
dtype: torch.dtype,
kv_cache_dtype: Optional[torch.dtype],
soft_cap: Optional[float],
) -> None:
kv_cache_dtype = dtype if kv_cache_dtype is None else kv_cache_dtype
if dtype != kv_cache_dtype:
pytest.skip(f"Not supported dtype({dtype}) with "
"kv_cache_dtype({kv_cache_dtype})")
torch.set_default_device("cuda")
current_platform.seed_everything(0)
q_lens = torch.randint(1, MAX_Q_LEN, (batch_size, ), dtype=torch.int32)
q_lens[-1] = MAX_Q_LEN
max_q_len = torch.max(q_lens).item()
q_indptr = torch.cat([
torch.tensor([0], dtype=torch.int32),
torch.cumsum(q_lens, dim=0, dtype=torch.int32),
])
kv_lens = torch.randint(0, MAX_KV_LEN, (batch_size, ), dtype=torch.int32)
kv_lens[-1] = MAX_KV_LEN
seq_lens = kv_lens + q_lens
max_seq_len = torch.max(seq_lens).item()
num_seqs = len(seq_lens)
num_query_heads = num_heads[0]
num_kv_heads = num_heads[1]
assert num_query_heads % num_kv_heads == 0
scale = head_size**-0.5
query = torch.randn(torch.sum(q_lens).item(),
num_query_heads,
head_size,
dtype=dtype)
kv_cache_shape = None
if kv_layout == "NHD":
kv_cache_shape = (NUM_BLOCKS, 2, block_size, num_kv_heads, head_size)
elif kv_layout == "HND":
kv_cache_shape = (NUM_BLOCKS, 2, num_kv_heads, block_size, head_size)
else:
raise ValueError(f"Invalid kv_layout: {kv_layout}")
key_value_cache = torch.randn(kv_cache_shape, dtype=dtype)
kv_scale = 1.0
if kv_cache_dtype is current_platform.fp8_dtype():
key_value_cache, kv_scale = to_float8(key_value_cache,
current_platform.fp8_dtype())
max_num_blocks_per_seq = (max_seq_len + block_size - 1) // block_size
block_tables = torch.randint(0,
NUM_BLOCKS,
(num_seqs, max_num_blocks_per_seq),
dtype=torch.int32)
k_scale = v_scale = kv_scale
kv_indptr = [0]
kv_indices = []
kv_last_page_lens = []
for i in range(num_seqs):
seq_len = seq_lens[i]
assert seq_len > 0
num_blocks = (seq_len + block_size - 1) // block_size
kv_indices.extend(block_tables[i, :num_blocks])
kv_indptr.append(kv_indptr[-1] + num_blocks)
kv_last_page_len = seq_len % block_size
if kv_last_page_len == 0:
kv_last_page_len = block_size
kv_last_page_lens.append(kv_last_page_len)
kv_indptr = torch.tensor(kv_indptr, dtype=torch.int32)
kv_indices = torch.tensor(kv_indices, dtype=torch.int32)
kv_last_page_lens = torch.tensor(kv_last_page_lens, dtype=torch.int32)
workspace_buffer = torch.empty(128 * 1024 * 1024, dtype=torch.int8)
wrapper = flashinfer.BatchPrefillWithPagedKVCacheWrapper(
workspace_buffer, kv_layout)
wrapper.plan(q_indptr,
kv_indptr,
kv_indices,
kv_last_page_lens,
num_query_heads,
num_kv_heads,
head_size,
block_size,
causal=True,
sm_scale=scale,
q_data_type=dtype,
kv_data_type=kv_cache_dtype,
logits_soft_cap=soft_cap)
output = torch.empty(query.shape, dtype=dtype)
wrapper.run(query,
key_value_cache,
k_scale=k_scale,
v_scale=v_scale,
out=output)
# TRTLLM Decode
output_trtllm = torch.empty(query.shape, dtype=dtype)
flashinfer.prefill.trtllm_batch_context_with_kv_cache(
query=query.contiguous(),
kv_cache=key_value_cache,
workspace_buffer=workspace_buffer,
block_tables=block_tables,
seq_lens=seq_lens,
max_q_len=max_q_len,
max_kv_len=max_seq_len,
bmm1_scale=k_scale * scale,
bmm2_scale=v_scale,
batch_size=num_seqs,
cum_seq_lens_q=q_indptr,
cum_seq_lens_kv=kv_indptr,
out=output_trtllm,
)
torch.testing.assert_close(output, output_trtllm, atol=1e-2, rtol=1e-2), \
f"{torch.max(torch.abs(output - output_trtllm))}"