Files
pytorch/test/inductor/test_flex_decoding.py
Catherine Lee 561193e5f2 [CI][testing] Use 3 processes for testing on sm89 and sm90 jobs (#158691)
3 procs were used for sm86, but we switched to sm89 and the check failed so it switched back to 2

sm90 is H100, but idk what unittests we have running there, but I assume they also have a lot of memory

They use larger runners, which have more GPU memory, so its usually ok.  I think it's ~22GB -> 10GB per proc if 2, 6GB per proc if 3 (cuda context maybe 1GB)

I've applied skips to the ones that OOMed

Time decreases from ~2.7hr per test job -> ~2hr

Pull Request resolved: https://github.com/pytorch/pytorch/pull/158691
Approved by: https://github.com/huydhn
2025-07-25 15:26:29 +00:00

2002 lines
64 KiB
Python

# Owner(s): ["module: inductor"]
# flake8: noqa: B950
import functools
import unittest
from collections import namedtuple
from typing import Callable, Optional, Union
from unittest import expectedFailure
from unittest.mock import patch
import torch
from torch._inductor.test_case import TestCase as InductorTestCase
from torch._inductor.utils import run_and_get_code
from torch.nn.attention.experimental._paged_attention import PagedAttention
from torch.nn.attention.flex_attention import (
_create_empty_block_mask,
_identity,
BlockMask,
create_block_mask,
flex_attention,
noop_mask,
)
from torch.testing import FileCheck
from torch.testing._internal import common_utils
from torch.testing._internal.common_cuda import PLATFORM_SUPPORTS_BF16
from torch.testing._internal.common_device_type import (
flex_attention_supported_platform as supported_platform,
instantiate_device_type_tests,
)
Tolerances = namedtuple("Tolerances", ["atol", "rtol"])
# In MI300, HIPBLASLT_ALLOW_TF32=1 is used to enable tf32 for matmul.
# In the current test, HIPBLASLT_ALLOW_TF32 is not set, according to the
# logic of allowTF32CuBLAS(), set float32_matmul_precision to highest.
if torch.version.hip:
torch.set_float32_matmul_precision("highest")
else:
torch.set_float32_matmul_precision("high")
index = torch.ops.aten.index
Tensor = torch.Tensor
TEST_ON_CUDA = (
torch.cuda.is_available()
and torch.utils._triton.has_triton()
and torch.cuda.get_device_capability() >= (8, 0)
)
if TEST_ON_CUDA:
test_device = ("cuda",)
test_dtypes = (
[torch.float32, torch.bfloat16, torch.float16]
if PLATFORM_SUPPORTS_BF16
else [torch.float16, torch.float32]
)
test_dtypes_fast = [torch.float16]
SKIP_UT_ON_CPU = False
else:
test_device = ("cpu",)
torch_config_string = torch.__config__.show()
SKIP_UT_ON_CPU = True
LONG_COMPILATION_ON_CPU = False
if "CLANG" in torch_config_string.upper():
# if the compiler is clang, skip UT for CPU due to long compilation time found in CI
# TODO: check reason of long compile time
LONG_COMPILATION_ON_CPU = True
test_dtypes = (
[torch.float32, torch.bfloat16]
if torch.backends.mkldnn.is_available()
and torch.ops.mkldnn._is_mkldnn_bf16_supported()
else [torch.float32]
)
test_dtypes_fast = [torch.float32]
def create_attention(score_mod, block_mask, enable_gqa=False):
return functools.partial(
flex_attention,
score_mod=score_mod,
block_mask=block_mask,
enable_gqa=enable_gqa,
)
def create_block_mask_test(score_mod, query, key):
block_mask = create_block_mask(
score_mod, 1, 1, query.shape[-2], key.shape[-2], query.device
)
return block_mask
test_page_sizes = [64, 128, 256]
# --------- Useful score mod functions for testing ---------
def _causal(
score: Tensor,
batch: Tensor,
head: Tensor,
token_q: Tensor,
token_kv: Tensor,
) -> Tensor:
return torch.where(token_q >= token_kv, score, float("-inf"))
def _generate_windowed(offset):
def _windowed(score, b, h, q, kv):
return torch.where(q + offset >= kv, score, float("-inf"))
return _windowed
def _get_windowed_sdpa_mask(Mq, Mkv, offset):
return torch.tril(torch.ones(Mkv, Mkv, dtype=torch.bool, device=test_device[0]))[
offset : offset + Mq
]
def _rel_bias(
score: Tensor,
batch: Tensor,
head: Tensor,
token_q: Tensor,
token_kv: Tensor,
) -> Tensor:
return score + (token_q - token_kv)
def _rel_causal(
score: Tensor,
batch: Tensor,
head: Tensor,
token_q: Tensor,
token_kv: Tensor,
) -> Tensor:
return torch.where(token_q >= token_kv, score + (token_q - token_kv), float("-inf"))
def _generate_alibi_bias(num_heads: int):
def _alibi_bias(
score: Tensor,
batch: Tensor,
head: Tensor,
token_q: Tensor,
token_kv: Tensor,
) -> Tensor:
scale = torch.exp2(-((head + 1) * 8.0 / num_heads))
return score + (token_kv - token_q) * scale
return _alibi_bias
def _inverse_causal(score, b, h, m, n):
return torch.where(m <= n, score, float("-inf"))
def _times_two(score, b, h, m, n):
"""Joint graph needed for correctness"""
return score * 2
def _squared(score, b, h, m, n):
"""Joint graph needed for correctness"""
return score * score
def _head_offset(dtype: torch.dtype):
"""Captured Buffer"""
head_offset = torch.rand(Hq, device=test_device[0], dtype=dtype)
def score_mod(score, b, h, m, n):
return score * head_offset[h]
return score_mod
def _trig(score, b, h, m, n):
"""Joint graph needed for correctness"""
return torch.sin(torch.cos(score)) + torch.tan(b)
def _trig2(score, b, h, m, n):
"""Branching joint graph"""
cos_score = torch.cos(score)
sin_score = torch.sin(score)
z = cos_score * sin_score + torch.tan(b)
return z
test_score_mods = [
_identity,
_times_two,
_squared,
_causal,
_inverse_causal,
_rel_bias,
_rel_causal,
_generate_alibi_bias(8),
_generate_windowed(1000),
]
captured_buffers_map = {
"_head_offset": _head_offset,
}
B = 4
S = 2048
D = 64
test_Hq_Hkv = [
(16, 1),
(8, 2),
(16, 16),
]
test_Bq_Bkv = [
(3, 1),
(5, 1),
(8, 1),
(16, 1),
]
test_block_size = [
64,
128,
(1, 64),
(128, 64),
]
(Hq, Hkv) = (16, 8)
def input_strides_1(B, H, S, D):
return ((H * S * D, S * D, D, 1), 997) # offset
def input_strides_2(B, H, S, D):
return ((H * D, D, B * H * D, 1), 499) # transposed dimensions
def input_strides_3(B, H, S, D):
return ((S * (D + 1), B * S * (D + 1), (D + 1), 1), 293) # additional buffer
def input_strides_4(B, H, S, D):
return ((1, D, (B + 1) * (H + 1) * D, 1), 97) # shared dimension
test_input_strides = [
input_strides_1,
input_strides_2,
input_strides_3,
input_strides_4,
]
def query_key_value_clones(
query: torch.Tensor,
key: torch.Tensor,
value: torch.Tensor,
dtype: torch.dtype = None,
):
"""Clones the query, key, and value tensors and moves them to the specified dtype."""
if dtype is None:
dtype = query.dtype
query_ref = query.detach().clone().to(dtype).requires_grad_(query.requires_grad)
key_ref = key.detach().clone().to(dtype).requires_grad_(key.requires_grad)
value_ref = value.detach().clone().to(dtype).requires_grad_(value.requires_grad)
return query_ref, key_ref, value_ref
def batch_reserve(paged_attention: PagedAttention, target_seq_len: Tensor):
(B,) = target_seq_len.shape
for b in range(B):
paged_attention.reserve(
torch.tensor(b),
target_seq_len[b],
)
class TestFlexDecoding(InductorTestCase):
def setUp(self):
super().setUp()
self.test_inference_only = False
if test_device[0] == "cpu":
if LONG_COMPILATION_ON_CPU:
self.skipTest(
"skip UT for CPU due to long compilation time found in CI"
)
self.test_inference_only = True
def _check_equal(
self,
golden_out: torch.Tensor,
ref_out: torch.Tensor,
compiled_out: torch.Tensor,
fudge_factor: float,
tensor_name: Optional[str] = None,
):
compiled_error = (golden_out - compiled_out).abs().mean()
ref_error = (golden_out - ref_out).abs().mean()
if torch.isnan(compiled_error).any() and not torch.isnan(ref_error).any():
self.assertTrue(False, "Output/Grad with NaN")
if ref_error < (1e-4) * golden_out.abs().mean():
print(
"very small ref error of ",
(ref_error.to(torch.float64) * (1e5) / golden_out.abs().mean()),
)
tolerance = Tolerances(atol=2e-1, rtol=2e-1)
torch.testing.assert_close(
golden_out.to(dtype=compiled_out.dtype),
compiled_out,
atol=tolerance.atol,
rtol=tolerance.rtol,
)
elif compiled_error > ref_error * fudge_factor:
name = tensor_name if tensor_name is not None else ""
msg = f"{name} Compiled error {compiled_error} is greater than ref error {ref_error} by more than {fudge_factor}X."
self.assertTrue(False, msg)
def _check_out(
self,
golden_out: torch.Tensor,
ref_out: torch.Tensor,
compiled_out: torch.Tensor,
):
dtype = ref_out.dtype
with torch.no_grad():
# Note, it seems like we really are less accurate than the float32
# computation, likely due to the online softmax
if dtype == torch.float32:
fudge_factor = 10.0
else:
fudge_factor = 1.1
# Checkout output
self._check_equal(golden_out, ref_out, compiled_out, fudge_factor, "Out")
def run_test(
self,
score_mod: Optional[Callable] = None,
dtype: torch.dtype = torch.float16,
Q_B: int = B,
Q_H: int = Hq,
Q_S: int = 1,
Q_D: int = D,
KV_B: int = B,
KV_H: int = Hkv,
KV_S: int = S,
V_D: int = D,
block_mask: Optional[BlockMask] = None,
device="cuda",
):
assert score_mod is not None or block_mask is not None, (
"Must provide score_mod or block_mask"
)
assert Q_H % KV_H == 0
if device == "cpu" and dtype is torch.float16:
dtype = torch.float32
q = torch.randn(
(Q_B, Q_H, Q_S, Q_D),
dtype=dtype,
device=device,
requires_grad=not self.test_inference_only,
)
k = torch.randn(
(KV_B, KV_H, KV_S, Q_D),
dtype=dtype,
device=device,
requires_grad=not self.test_inference_only,
)
v = torch.randn(
(KV_B, KV_H, KV_S, V_D),
dtype=dtype,
device=device,
requires_grad=not self.test_inference_only,
)
q_ref, k_ref, v_ref = query_key_value_clones(q, k, v)
q_gold, k_gold, v_gold = query_key_value_clones(q, k, v, torch.float64)
sdpa_partial = create_attention(
score_mod, block_mask, enable_gqa=(not Q_H == KV_H)
)
compiled_sdpa = torch.compile(sdpa_partial)
if not self.test_inference_only:
golden_out, gold_lse = sdpa_partial(q_gold, k_gold, v_gold, return_lse=True)
ref_out, ref_lse = sdpa_partial(q_ref, k_ref, v_ref, return_lse=True)
compiled_out, compiled_lse = compiled_sdpa(q, k, v, return_lse=True)
self._check_out(
gold_lse,
ref_lse,
compiled_lse,
)
else:
golden_out = sdpa_partial(q_gold, k_gold, v_gold, return_lse=False)
ref_out = sdpa_partial(q_ref, k_ref, v_ref, return_lse=False)
compiled_out = compiled_sdpa(q, k, v, return_lse=False)
self._check_out(
golden_out,
ref_out,
compiled_out,
)
def run_test_with_call(
self,
sdpa_call: Callable,
golden_call: Optional[Callable] = None,
dtype: torch.dtype = torch.float16,
Q_B: int = B,
Q_H: int = Hq,
Q_S: int = 1,
Q_D: int = D,
KV_B: int = B,
KV_H: int = Hkv,
KV_S: int = S,
V_D: int = D,
device="cuda",
):
if not golden_call:
golden_call = sdpa_call
if device == "cpu" and dtype is torch.float16:
dtype = torch.float32
q = torch.randn(
(Q_B, KV_H, Q_S, Q_D),
dtype=dtype,
device=device,
requires_grad=False,
)
k = torch.randn(
(KV_B, KV_H, KV_S, Q_D),
dtype=dtype,
device=device,
requires_grad=False,
)
v = torch.randn(
(KV_B, KV_H, KV_S, V_D),
dtype=dtype,
device=device,
requires_grad=False,
)
q_ref, k_ref, v_ref = query_key_value_clones(q, k, v)
q_gold, k_gold, v_gold = query_key_value_clones(q, k, v, torch.float64)
compiled_sdpa = torch.compile(sdpa_call)
golden_out = golden_call(q_gold, k_gold, v_gold)
ref_out = golden_call(q_ref, k_ref, v_ref)
compiled_out = compiled_sdpa(q, k, v)
self._check_out(
golden_out,
ref_out,
compiled_out,
)
def preprocess_paged_attention(
self,
score_mod: Optional[Callable],
q: Tensor,
k: Tensor,
v: Tensor,
block_mask,
dtype: torch.dtype = torch.float16,
page_size: int = 128,
device="cuda",
):
assert block_mask is not None, "Must provide block_mask"
if device == "cpu" and dtype is torch.float16:
dtype = torch.float32
Q_B, Q_H, Q_S, _ = q.shape
KV_B, KV_H, KV_S, QK_D = k.shape
_, _, _, V_D = v.shape
# test with different batch size
max_batch_size = max(Q_B, KV_B) + 3
n_pages = (KV_S + page_size - 1) // page_size * max_batch_size
# allocate cache
MAX_CACHED_SEQ_LEN = n_pages * page_size
k_cache = torch.zeros(
1,
KV_H,
MAX_CACHED_SEQ_LEN,
QK_D,
device=device,
dtype=dtype,
)
v_cache = torch.zeros(
1,
KV_H,
MAX_CACHED_SEQ_LEN,
V_D,
device=device,
dtype=dtype,
)
# "randomly" initialize the page table
paged_attention = PagedAttention(
n_pages, page_size, max_batch_size, device=device
)
batch_reserve(
paged_attention,
torch.tensor([KV_S // 4, KV_S // 2, KV_S // 4, KV_S // 3], device=device),
)
batch_reserve(
paged_attention,
torch.tensor([KV_S // 4, KV_S // 2, KV_S // 2, KV_S // 2], device=device),
)
batch_reserve(
paged_attention,
torch.tensor([KV_S // 2, KV_S, KV_S // 2, KV_S], device=device),
)
batch_reserve(
paged_attention, torch.tensor([KV_S, KV_S, KV_S, KV_S], device=device)
)
# update cache with k and v
input_pos = (
torch.arange(KV_S, device=device, dtype=torch.int32)
.unsqueeze(0)
.expand(KV_B, KV_S)
)
batch_idx = torch.arange(KV_B, device=device, dtype=torch.int32)
paged_attention.assign(batch_idx, input_pos, k, v, k_cache, v_cache)
# convert block mask and score mod
converted_block_mask = paged_attention.convert_logical_block_mask(block_mask)
converted_score_mod = paged_attention.get_score_mod(score_mod)
return k_cache, v_cache, converted_block_mask, converted_score_mod
def run_paged_attention(
self,
score_mod: Optional[Callable],
q: Tensor,
k: Tensor,
v: Tensor,
dtype: torch.dtype = torch.float16,
block_mask: Optional[BlockMask] = None,
device="cuda",
):
Q_B, Q_H, KV_H = q.shape[0], q.shape[1], k.shape[1]
if device == "cpu" and dtype is torch.float16:
dtype = torch.float32
if block_mask is None:
block_mask = create_block_mask(noop_mask, Q_B, 1, 1, S, device=device)
(
k_cache,
v_cache,
converted_block_mask,
converted_score_mod,
) = self.preprocess_paged_attention(
score_mod, q, k, v, block_mask, dtype, block_mask.BLOCK_SIZE[1], device
)
compiled_sdpa = torch.compile(flex_attention)
# compute
if not self.test_inference_only:
compiled_out, compiled_lse = compiled_sdpa(
q,
k_cache,
v_cache,
return_lse=True,
block_mask=converted_block_mask,
score_mod=converted_score_mod,
enable_gqa=(not Q_H == KV_H),
)
else:
compiled_lse = None
compiled_out = compiled_sdpa(
q,
k_cache,
v_cache,
return_lse=False,
block_mask=converted_block_mask,
score_mod=converted_score_mod,
enable_gqa=(not Q_H == KV_H),
)
return compiled_out, compiled_lse
def run_test_with_paged_attention(
self,
score_mod: Optional[Callable],
dtype: torch.dtype = torch.float16,
Q_B: int = B,
Q_H: int = Hq,
Q_S: int = 1,
QK_D: int = D,
KV_B: int = B,
KV_H: int = Hkv,
KV_S: int = S,
V_D: int = D,
block_mask: Optional[BlockMask] = None,
device="cuda",
):
assert Q_H % KV_H == 0
if device == "cpu" and dtype is torch.float16:
dtype = torch.float32
q = torch.randn(
(Q_B, Q_H, Q_S, QK_D),
dtype=dtype,
device=device,
requires_grad=False,
)
k = torch.randn(
(KV_B, KV_H, KV_S, QK_D),
dtype=dtype,
device=device,
requires_grad=False,
)
v = torch.randn(
(KV_B, KV_H, KV_S, V_D),
dtype=dtype,
device=device,
requires_grad=False,
)
q_ref, k_ref, v_ref = query_key_value_clones(q, k, v)
q_gold, k_gold, v_gold = query_key_value_clones(q, k, v, torch.float64)
if block_mask is None:
block_mask = create_block_mask(noop_mask, Q_B, 1, 1, KV_S, device=device)
sdpa_partial = create_attention(
score_mod, block_mask, enable_gqa=(not Q_H == KV_H)
)
golden_out, gold_lse = sdpa_partial(q_gold, k_gold, v_gold, return_lse=True)
ref_out, ref_lse = sdpa_partial(q_ref, k_ref, v_ref, return_lse=True)
compiled_out, compiled_lse = self.run_paged_attention(
score_mod, q, k, v, dtype, block_mask, device
)
self._check_out(
golden_out,
ref_out,
compiled_out,
)
if not self.test_inference_only:
self._check_out(
gold_lse,
ref_lse,
compiled_lse,
)
def run_test_with_call_paged_attention(
self,
score_mod: Optional[Callable],
mask_mod: Optional[Callable],
sdpa_mask: Tensor,
dtype: torch.dtype = torch.float16,
Q_B: int = B,
Q_H: int = Hq,
Q_S: int = 1,
Q_D: int = D,
KV_B: int = B,
KV_H: int = Hkv,
KV_S: int = S,
V_D: int = D,
device="cuda",
):
if device == "cpu" and dtype is torch.float16:
dtype = torch.float32
q = torch.randn(
(Q_B, KV_H, Q_S * (Q_H // KV_H), Q_D),
dtype=dtype,
device=device,
requires_grad=False,
)
k = torch.randn(
(KV_B, KV_H, KV_S, Q_D),
dtype=dtype,
device=device,
requires_grad=False,
)
v = torch.randn(
(KV_B, KV_H, KV_S, V_D),
dtype=dtype,
device=device,
requires_grad=False,
)
q_ref, k_ref, v_ref = query_key_value_clones(q, k, v)
q_gold, k_gold, v_gold = query_key_value_clones(q, k, v, torch.float64)
golden_call = functools.partial(
torch.nn.functional.scaled_dot_product_attention, attn_mask=sdpa_mask
)
golden_out = golden_call(q_gold, k_gold, v_gold)
ref_out = golden_call(q_ref, k_ref, v_ref)
if mask_mod is not None:
block_mask = create_block_mask(mask_mod, Q_B, 1, Q_S, KV_S, device=device)
else:
block_mask = create_block_mask(noop_mask, Q_B, 1, Q_S, KV_S, device=device)
compiled_out, _ = self.run_paged_attention(
score_mod, q, k, v, dtype, block_mask, device
)
self._check_out(
golden_out,
ref_out,
compiled_out,
)
@supported_platform
@expectedFailure
@unittest.skipIf(SKIP_UT_ON_CPU, "Skip on CPU as not supported")
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_bw_decoding_fails(self, dtype):
make_kv = functools.partial(
torch.randn,
(2, 2, 128, 4),
dtype=dtype,
device="cuda",
requires_grad=True,
)
make_q = functools.partial(
torch.randn,
(2, 2, 8, 4),
dtype=dtype,
device="cuda",
requires_grad=True,
)
q, k, v, backward_grad = make_q(), make_kv(), make_kv(), make_q()
block_mask = _create_empty_block_mask(q, k)
@torch.compile
def sdpa_hop(q, k, v, score_mod, block_mask):
return flex_attention(q, k, v, score_mod)
output = sdpa_hop(q, k, v, _identity, block_mask)
output.backward(backward_grad)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes)
@common_utils.parametrize("score_mod", test_score_mods)
@common_utils.parametrize("head_dims", test_Hq_Hkv)
def test_builtin_score_mods(
self, device, dtype: torch.dtype, score_mod: Callable, head_dims
):
Hq, Hkv = head_dims
assert Hq % Hkv == 0
self.run_test(score_mod, dtype, Q_H=Hq, KV_H=Hkv, device=device)
self.run_test_with_paged_attention(
score_mod, dtype, Q_H=Hq, KV_H=Hkv, device=device
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
@common_utils.parametrize("score_mod", test_score_mods)
@common_utils.parametrize("head_dims", test_Hq_Hkv)
@common_utils.parametrize("page_size", test_page_sizes)
def test_paged_attention_page_size(
self,
device,
dtype: torch.dtype,
score_mod: Callable,
head_dims: tuple[int, int],
page_size: int,
):
Hq, Hkv = head_dims
assert Hq % Hkv == 0
def generate_causal_offset(offset: torch.Tensor):
def causal_offset_mask(b, h, q_idx, kv_idx):
return (offset + q_idx) >= kv_idx
return causal_offset_mask
mod = generate_causal_offset(
torch.tensor(192, device=device, dtype=torch.int32)
)
block_mask = create_block_mask(
mod, B, 1, 1, S, BLOCK_SIZE=page_size, device=device
)
self.run_test_with_paged_attention(
score_mod,
dtype,
Q_B=B,
Q_H=Hq,
KV_B=B,
KV_H=Hkv,
KV_S=S,
block_mask=block_mask,
device=device,
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes)
@common_utils.parametrize("score_mod", test_score_mods)
@common_utils.parametrize("BLOCK_SIZE", test_block_size)
def test_builtin_score_mods_different_block_size(
self,
device,
dtype: torch.dtype,
score_mod: Callable,
BLOCK_SIZE: Union[int, tuple[int, int]],
):
block_mask = create_block_mask(
noop_mask, B, 1, 1, S, BLOCK_SIZE=BLOCK_SIZE, device=device
)
self.run_test(score_mod, dtype, block_mask=block_mask, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
@common_utils.parametrize("k_s", test_input_strides)
@common_utils.parametrize("v_s", test_input_strides)
@common_utils.parametrize("head_dims", test_Hq_Hkv)
def test_strided_inputs(self, device, dtype: torch.dtype, k_s, v_s, head_dims):
Hq, Hkv = head_dims
assert Hq % Hkv == 0
q1 = torch.randn((B * Hq * D), dtype=dtype, device=device)
k1 = torch.randn((B * Hkv * S * D * 4), dtype=dtype, device=device)
v1 = torch.randn((B * Hkv * S * D * 4), dtype=dtype, device=device)
k_shape = (B, Hkv, S, D)
v_shape = (B, Hkv, S, D)
q = q1.view(1, Hq, B, D).transpose(0, 2)
k_strides, k_offset = k_s(B, Hkv, S, D)
k_max = [x * (y - 1) for x, y in zip(k_strides, k_shape)]
assert sum(k_max) + k_offset < B * Hkv * S * D * 4
assert k_strides[-1] == 1
k = torch.as_strided(k1, k_shape, k_strides, k_offset)
v_strides, v_offset = v_s(B, Hkv, S, D)
v_max = [x * (y - 1) for x, y in zip(v_strides, v_shape)]
assert sum(v_max) + v_offset < B * Hkv * S * D * 4
assert v_strides[-1] == 1
v = torch.as_strided(v1, v_shape, v_strides, v_offset)
score_mod = _generate_alibi_bias(8)
sdpa_partial = create_attention(
score_mod=score_mod,
block_mask=None,
enable_gqa=(not Hq == Hkv),
)
compiled_sdpa = torch.compile(sdpa_partial)
ref_out = sdpa_partial(q, k, v)
compiled_out = compiled_sdpa(q, k, v)
tolerance = Tolerances(atol=2e-1, rtol=2e-1)
torch.testing.assert_close(
ref_out, compiled_out, atol=tolerance.atol, rtol=tolerance.rtol
)
paged_compiled_out, _ = self.run_paged_attention(
score_mod, q, k, v, dtype, device=device
)
torch.testing.assert_close(
ref_out, paged_compiled_out, atol=tolerance.atol, rtol=tolerance.rtol
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
@common_utils.parametrize("head_dims", test_Hq_Hkv)
@common_utils.parametrize("batch_dims", test_Bq_Bkv)
@common_utils.parametrize("score_mod", test_score_mods)
def test_kv_batch_broadcast(
self,
device,
dtype: torch.dtype,
head_dims: tuple[int, int],
batch_dims: tuple[int, int],
score_mod: Callable,
):
Hq, Hkv = head_dims
assert Hq % Hkv == 0
Bq, Bkv = batch_dims
assert Bq > 1 and Bkv == 1
block_mask = create_block_mask(noop_mask, Bq, 1, 1, S, device=device)
self.run_test(
score_mod, dtype, Bq, Hq, 1, D, Bkv, Hkv, S, D, block_mask, device=device
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes)
def test_skip_odd_keys(self, device, dtype: torch.dtype):
def score_mod(score, b, h, q, kv):
return torch.where(kv % 2 == 0, score, float("-inf"))
self.run_test(score_mod, dtype, device=device)
self.run_test_with_paged_attention(score_mod, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes)
def test_function_composition(self, device, dtype: torch.dtype):
def score_mod_1(score, b, h, m, n):
return score + (m - n)
def score_mod_2(score, b, h, m, n):
return torch.where(m <= n, score, float("-inf"))
def composed_score_mod(score, b, h, m, n):
return score_mod_2(score_mod_1(score, b, h, m, n), b, h, m, n)
self.run_test(composed_score_mod, dtype, device=device)
self.run_test_with_paged_attention(composed_score_mod, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes)
def test_captured_buffers(self, device, dtype: torch.dtype):
head_offset = torch.rand(Hq, device=device, dtype=dtype)
def score_mod(score, b, h, m, n):
return score + head_offset[h]
self.run_test(score_mod, dtype, device=device)
self.run_test_with_paged_attention(score_mod, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes)
def test_captured_buffers_all_dims(self, device, dtype: torch.dtype):
head_scale = torch.randn(Hq, device=device)
batch_scale = torch.randn(B, device=device)
kv_scale = torch.randn(S, device=device)
q_scale = torch.randn(1, device=device)
def all_bias(score, batch, head, token_q, token_kv):
score = score + kv_scale[token_kv]
score = score + q_scale[token_q]
score = score + head_scale[head]
score = score + batch_scale[batch]
return score
self.run_test(all_bias, dtype, device=device)
self.run_test_with_paged_attention(all_bias, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_seq_masking(self, device, dtype):
seq_idx = torch.zeros(S, device=device, dtype=torch.bool)
seq_idx[S // 2 :] = 1
def seq_mask_mod(score, b, h, q, kv):
return torch.where(seq_idx[q] == seq_idx[kv], score, float("-inf"))
self.run_test(seq_mask_mod, dtype, device=device)
self.run_test_with_paged_attention(seq_mask_mod, dtype, device=device)
@supported_platform
def test_non_divisible_offset_mask(self, device):
KV_S = S - 3
offset_tensor = torch.tensor(S // 2 - 3, device=device, dtype=torch.int32)
def mask_mod(b, h, q, kv):
return kv >= q + offset_tensor
block_mask = create_block_mask(mask_mod, B, 1, 1, KV_S, device=device)
self.run_test(KV_S=KV_S, block_mask=block_mask, device=device)
@supported_platform
def test_non_divisible_offset_mask_with_captured_buffer(self, device):
KV_S = S - 3
offset_kv = torch.randn(KV_S, device=device, dtype=torch.bfloat16)
offset_tensor = torch.tensor(S // 2 - 3, device=device, dtype=torch.int32)
def score_mod(score, b, h, q, kv):
return score + offset_kv[kv]
def mask_mod(b, h, q, kv):
return kv >= q + offset_tensor
block_mask = create_block_mask(mask_mod, B, 1, 1, KV_S, device=device)
self.run_test(
KV_S=KV_S, block_mask=block_mask, score_mod=score_mod, device=device
)
@supported_platform
def test_non_divisible_multi_token_offset_mask(self, device):
KV_S = S - 3
Q_S = 3
offset_tensor = torch.tensor(S // 2 - 1, device=device, dtype=torch.int32)
def mask_mod(b, h, q, kv):
return kv >= q + offset_tensor
block_mask = create_block_mask(mask_mod, B, 1, Q_S, KV_S, device=device)
self.run_test(Q_S=Q_S, KV_S=KV_S, block_mask=block_mask, device=device)
@supported_platform
@unittest.skipIf(SKIP_UT_ON_CPU, "Skip on CPU as not supported")
def test_non_divisible_multi_token_offset_mask_with_captured_buffer(self):
KV_S = S - 3
Q_S = 3
offset_kv = torch.randn(KV_S, device="cuda", dtype=torch.bfloat16)
offset_q = torch.randn(Q_S, device="cuda", dtype=torch.bfloat16)
offset_tensor = torch.tensor(S // 2 - 3, device="cuda", dtype=torch.int32)
def score_mod(score, b, h, q, kv):
return score + offset_kv[kv] + offset_q[q]
def mask_mod(b, h, q, kv):
return kv >= q + offset_tensor
block_mask = create_block_mask(mask_mod, B, 1, Q_S, KV_S)
self.run_test(Q_S=Q_S, KV_S=KV_S, block_mask=block_mask, score_mod=score_mod)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_load_from_bias_seq_only(self, device, dtype):
bias = torch.randn(1, S, device=device, dtype=dtype)
def bias_mod(score, b, h, q, kv):
return score + bias[q, kv]
self.run_test(bias_mod, dtype, device=device)
self.run_test_with_paged_attention(bias_mod, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_load_from_bias_seq_batch(self, device, dtype):
bias = torch.randn(B, 1, S, device=device, dtype=dtype)
def bias_mod(score, b, h, q, kv):
return score + bias[b, q, kv]
self.run_test(bias_mod, dtype, device=device)
self.run_test_with_paged_attention(bias_mod, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_load_from_bias_head_seq_batch(self, device, dtype):
bias = torch.randn(
B,
Hq,
1,
S,
device=device,
dtype=dtype,
)
def bias_mod(score, b, h, q, kv):
return score + bias[b, h, q, kv]
self.run_test(bias_mod, dtype, device=device)
self.run_test_with_paged_attention(bias_mod, dtype, device=device)
@supported_platform
@common_utils.parametrize("score_mod", test_score_mods)
@common_utils.parametrize("dtype", test_dtypes)
@common_utils.parametrize("head_dims", [(D, D // 2), (D // 2, D)])
def test_non_equal_head_dims(self, device, dtype, score_mod, head_dims):
qk_d, v_d = head_dims
self.run_test(
score_mod, dtype, B, Hq, 1, qk_d, B, Hkv, S, V_D=v_d, device=device
)
self.run_test_with_paged_attention(
score_mod, dtype, B, Hq, 1, qk_d, B, Hkv, S, V_D=v_d, device=device
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
@common_utils.parametrize("score_mod", test_score_mods)
@common_utils.parametrize("head_dims", test_Hq_Hkv)
def test_head_dependent_mask_mod(
self, device, dtype: torch.dtype, score_mod, head_dims
):
Hq, Hkv = head_dims
assert Hq % Hkv == 0
def head_attention_mod(kv_head_num):
head_type = torch.tensor(
[False if i % kv_head_num == 0 else True for i in range(kv_head_num)],
dtype=torch.bool,
device=device,
)
def mask_mod(b, h, q_idx, kv_idx):
bi_mask = head_type[h]
causal_mask = q_idx >= kv_idx
return bi_mask & causal_mask
return mask_mod
mask_mod = head_attention_mod(Hq)
mask = create_block_mask(mask_mod, 1, Hq, 1, S, device=device)
self.run_test(
score_mod, dtype, Q_H=Hq, KV_H=Hkv, block_mask=mask, device=device
)
self.run_test_with_paged_attention(
score_mod, dtype, Q_H=Hq, KV_H=Hkv, device=device
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_subgraph_respect_decompostion(self, device, dtype):
from torch._decomp import core_aten_decompositions
from torch.fx.experimental.proxy_tensor import make_fx
def score_mod_func(score, b, h, q, kv):
return score - q // (1 + kv)
make_kv = functools.partial(
torch.randn,
(2, 2, 128, 4),
dtype=dtype,
device=device,
requires_grad=True,
)
make_q = functools.partial(
torch.randn,
(2, 2, 8, 4),
dtype=dtype,
device=device,
requires_grad=True,
)
query, key, value = make_q(), make_kv(), make_kv()
# floor_div is not decomposed in decompostion_table is empty
attention = functools.partial(flex_attention, score_mod=score_mod_func)
gm = make_fx(attention, decomposition_table={})(query, key, value)
self.assertExpectedInline(
gm.sdpa_score0.code.strip(),
"""\
def forward(self, arg0_1, arg1_1, arg2_1, arg3_1, arg4_1):
add = torch.ops.aten.add.Tensor(arg4_1, 1); arg4_1 = None
floor_divide = torch.ops.aten.floor_divide.default(arg3_1, add); arg3_1 = add = None
sub = torch.ops.aten.sub.Tensor(arg0_1, floor_divide); arg0_1 = floor_divide = None
return sub""",
)
# floor_div is decomposed for core_aten_decompositions
gm = make_fx(attention, decomposition_table=core_aten_decompositions())(
query, key, value
)
self.assertExpectedInline(
gm.sdpa_score0.code.strip(),
"""\
def forward(self, arg0_1, arg1_1, arg2_1, arg3_1, arg4_1):
add = torch.ops.aten.add.Tensor(arg4_1, 1); arg4_1 = None
div = torch.ops.aten.div.Tensor_mode(arg3_1, add, rounding_mode = 'floor'); arg3_1 = add = None
sub = torch.ops.aten.sub.Tensor(arg0_1, div); arg0_1 = div = None
return sub""",
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_silu_on_score(self, device, dtype):
def silu_score(score, b, h, q, kv):
return torch.nn.functional.silu(score)
self.run_test(silu_score, dtype, device=device)
self.run_test_with_paged_attention(silu_score, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_padded_dense_causal(self, device, dtype):
seq_len = torch.arange(B, device=device, dtype=torch.int32) + 1
def create_padded_dense_wrapper(orig_score_mod):
def njt_score_mod(qk, b, h, q, kv):
return torch.where(
qk <= seq_len[b], orig_score_mod(qk, b, h, q, kv), -float("inf")
)
return njt_score_mod
causal_njt = create_padded_dense_wrapper(_causal)
self.run_test(causal_njt, dtype, device=device)
self.run_test_with_paged_attention(causal_njt, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_captured_scale(self, device, dtype):
scale = torch.ones((), device=device, dtype=torch.int32)
def score_mod_scale(qk, b, h, q, kv):
return qk + scale
self.run_test(score_mod_scale, dtype, device=device)
self.run_test_with_paged_attention(score_mod_scale, dtype, device=device)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_recompile_changed_score_mod(self, device, dtype):
scale = torch.ones((), device=device, dtype=torch.int32)
ADD = True
def score_mod_scale(qk, b, h, q, kv):
if ADD:
return qk + scale
else:
return qk * scale
self.run_test(score_mod_scale, dtype, device=device)
self.run_test_with_paged_attention(score_mod_scale, dtype, device=device)
ADD = False
self.run_test(score_mod_scale, dtype, device=device)
self.run_test_with_paged_attention(score_mod_scale, dtype, device=device)
@supported_platform
@common_utils.parametrize("head_dim", [17, 24, 94, 121])
@common_utils.parametrize("dtype", test_dtypes_fast)
@common_utils.serialTest()
def test_non_pow_2_headdim(self, device, dtype, head_dim):
self.run_test(
_rel_bias, dtype, B, Hq, S, head_dim, B, Hkv, S, head_dim, device=device
)
@supported_platform
@expectedFailure # If we capture a tensor then we can perform a reduction on it, and that shouldn't be allowed
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_captured_reduction(self, device, dtype):
scale = torch.randn((B, 8), device=device)
def score_mod_scale(qk, b, h, q, kv):
return qk + scale[b].sum(dim=-1)
self.run_test(score_mod_scale, dtype, device=device)
@supported_platform
def test_multiple_score_mod_calls(self, device):
query = torch.randn((1, 8, 4, 64), dtype=torch.float32, device=device)
keys = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(2)
]
values = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(2)
]
def scoremod_1(qk, b, h, q, kv):
return qk + (q - kv)
def scoremod_2(qk, b, h, q, kv):
return torch.where(q >= kv, qk, -float("inf"))
def f(q, k1, k2, v1, v2):
q2 = flex_attention(q, k1, v1, score_mod=scoremod_1)
return flex_attention(q2, k2, v2, score_mod=scoremod_2)
out = f(query, *keys, *values)
out2 = torch.compile(f)(query, *keys, *values)
tolerance = Tolerances(atol=2e-1, rtol=2e-1)
torch.testing.assert_close(out, out2, atol=tolerance.atol, rtol=tolerance.rtol)
@supported_platform
def test_multiple_score_mod_calls2(self, device):
query = torch.randn((1, 8, 4, 64), dtype=torch.float32, device=device)
keys = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(3)
]
values = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(3)
]
def scoremod_1(qk, b, h, q, kv):
return qk + (q - kv)
def scoremod_2(qk, b, h, q, kv):
return torch.where(q >= kv, qk, -float("inf"))
attention1 = functools.partial(flex_attention, score_mod=scoremod_1)
def f(q, k1, k2, k3, v1, v2, v3):
q2 = attention1(q, k1, v1)
q3 = flex_attention(q2, k2, v2, score_mod=scoremod_2)
return flex_attention(q3, k3, v3, score_mod=scoremod_1)
out = f(query, *keys, *values)
out2 = torch.compile(f)(query, *keys, *values)
self.assertTrue((out - out2).abs().mean() < 1e-2)
@supported_platform
def test_multiple_score_mod_calls_paged_attention(self, device):
query = torch.randn((1, 8, 4, 64), dtype=torch.float32, device=device)
keys = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(2)
]
values = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(2)
]
def scoremod_1(qk, b, h, q, kv):
return qk + (q - kv)
def scoremod_2(qk, b, h, q, kv):
return torch.where(q >= kv, qk, -float("inf"))
block_mask = create_block_mask(noop_mask, 1, 1, 4, 1024, device=device)
def f(q, k1, k2, v1, v2):
q2 = flex_attention(q, k1, v1, score_mod=scoremod_1, block_mask=block_mask)
return flex_attention(
q2, k2, v2, score_mod=scoremod_2, block_mask=block_mask
)
eager_out = f(query, *keys, *values)
(
k_cache1,
v_cache1,
converted_block_mask1,
converted_score_mod1,
) = self.preprocess_paged_attention(
scoremod_1,
query,
keys[0],
values[0],
block_mask,
torch.float32,
device=device,
)
(
k_cache2,
v_cache2,
converted_block_mask2,
converted_score_mod2,
) = self.preprocess_paged_attention(
scoremod_2,
query,
keys[1],
values[1],
block_mask,
torch.float32,
device=device,
)
def paged_f(q, k1, k2, v1, v2):
q2 = flex_attention(
q,
k1,
v1,
score_mod=converted_score_mod1,
block_mask=converted_block_mask1,
)
return flex_attention(
q2,
k2,
v2,
score_mod=converted_score_mod2,
block_mask=converted_block_mask2,
)
compiled_out = torch.compile(paged_f)(
query, k_cache1, k_cache2, v_cache1, v_cache2
)
tolerance = Tolerances(atol=2e-1, rtol=2e-1)
torch.testing.assert_close(
eager_out, compiled_out, atol=tolerance.atol, rtol=tolerance.rtol
)
@supported_platform
def test_multiple_score_mod_calls_paged_attention2(self, device):
query = torch.randn((1, 8, 4, 64), dtype=torch.float32, device=device)
keys = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(3)
]
values = [
torch.randn((1, 8, 1024, 64), dtype=torch.float32, device=device)
for _ in range(3)
]
def scoremod_1(qk, b, h, q, kv):
return qk + (q - kv)
def scoremod_2(qk, b, h, q, kv):
return torch.where(q >= kv, qk, -float("inf"))
block_mask = create_block_mask(noop_mask, 1, 1, 4, 1024, device=device)
attention1 = functools.partial(
flex_attention, score_mod=scoremod_1, block_mask=block_mask
)
def f(q, k1, k2, k3, v1, v2, v3):
q2 = attention1(q, k1, v1)
q3 = flex_attention(q2, k2, v2, score_mod=scoremod_2, block_mask=block_mask)
return flex_attention(
q3, k3, v3, score_mod=scoremod_1, block_mask=block_mask
)
eager_out = f(query, *keys, *values)
(
k_cache1,
v_cache1,
converted_block_mask1,
converted_score_mod1,
) = self.preprocess_paged_attention(
scoremod_1,
query,
keys[0],
values[0],
block_mask,
torch.float32,
device=device,
)
(
k_cache2,
v_cache2,
converted_block_mask2,
converted_score_mod2,
) = self.preprocess_paged_attention(
scoremod_2,
query,
keys[1],
values[1],
block_mask,
torch.float32,
device=device,
)
(
k_cache3,
v_cache3,
converted_block_mask3,
converted_score_mod3,
) = self.preprocess_paged_attention(
scoremod_1,
query,
keys[2],
values[2],
block_mask,
torch.float32,
device=device,
)
paged_attention1 = functools.partial(
flex_attention,
score_mod=converted_score_mod1,
block_mask=converted_block_mask1,
)
def paged_f(q, k1, k2, k3, v1, v2, v3):
q2 = paged_attention1(q, k1, v1)
q3 = flex_attention(
q2,
k2,
v2,
score_mod=converted_score_mod2,
block_mask=converted_block_mask2,
)
return flex_attention(
q3,
k3,
v3,
score_mod=converted_score_mod3,
block_mask=converted_block_mask3,
)
compiled_out = torch.compile(paged_f)(
query, k_cache1, k_cache2, k_cache3, v_cache1, v_cache2, v_cache3
)
tolerance = Tolerances(atol=2e-1, rtol=2e-1)
torch.testing.assert_close(
eager_out, compiled_out, atol=tolerance.atol, rtol=tolerance.rtol
)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes)
def test_njt_causal(self, device, dtype):
offsets = torch.tensor(
[0, 1024, 1024 + 512, S], device=device, dtype=torch.int32
)
seq_idx = torch.zeros(S, device=device, dtype=torch.int32)
for idx in range(len(offsets) - 1):
seq_idx[offsets[idx] : offsets[idx + 1]] = idx
def create_njt_wrapper(orig_score_mod, offsets, seq_idx):
def njt_score_mod(qk, b, h, q, kv):
q_nested = q - offsets[seq_idx[q]]
kv_nested = kv - offsets[seq_idx[kv]]
return orig_score_mod(qk, b, h, q_nested, kv_nested)
return njt_score_mod
causal_njt = create_njt_wrapper(_causal, offsets, seq_idx)
self.run_test(causal_njt, dtype, device=device)
self.run_test_with_paged_attention(causal_njt, dtype, device=device)
@supported_platform
def test_mixed_dtypes_fails(self, device):
query = torch.randn((1, 1, 8, 64), dtype=torch.float32, device=device)
key = torch.randn((1, 1, 1024, 64), dtype=torch.float16, device=device)
value = torch.randn((1, 1, 1024, 64), dtype=torch.float16, device=device)
with self.assertRaisesRegex(
ValueError, "Expected query, key, and value to have the same dtype"
):
flex_attention(query, key, value, _identity)
@supported_platform
@patch.object(torch._inductor.config, "max_autotune", True)
def test_max_autotune(self, device):
def score_mod(score, b, h, m, n):
return score * 2
self.run_test(score_mod, device=device)
self.run_test_with_paged_attention(score_mod, device=device)
@supported_platform
@patch.object(torch._inductor.config, "max_autotune", True)
def test_max_autotune_with_captured(self, device):
head_scale = torch.randn(Hq, device=device)
batch_scale = torch.randn(B, device=device)
tok_scale = torch.randn(S, device=device)
q_scale = torch.randn(1, device=device)
def bias_mod(score, batch, head, token_q, token_kv):
score = score + tok_scale[token_kv]
score = score + q_scale[token_q]
score = score + batch_scale[batch]
score = score + head_scale[head]
return score
self.run_test(bias_mod, device=device)
self.run_test_with_paged_attention(bias_mod, device=device)
@supported_platform
def test_fully_masked_out_rows_0_check_gqa(self, device):
# Ensure fully masked out rows won't cause NaNs.
query = torch.randn(
(B, Hq, S, D),
dtype=torch.float32,
device=device,
requires_grad=not self.test_inference_only,
)
key = torch.randn(
(B, Hkv, S, D),
dtype=torch.float32,
device=device,
requires_grad=not self.test_inference_only,
)
value = torch.randn(
(B, Hkv, S, D),
dtype=torch.float32,
device=device,
requires_grad=not self.test_inference_only,
)
M = S // 2
def mask_mod(b, h, q, kv):
return q < M
block_mask = create_block_mask(mask_mod, 1, 1, S, S, device=device)
flex = torch.compile(flex_attention, dynamic=False)
if not self.test_inference_only:
out, lse = flex(
query,
key,
value,
block_mask=block_mask,
enable_gqa=True,
return_lse=True,
)
self.assertTrue((lse[:, :, M:] == -float("inf")).all())
loss = out.sum() + lse.sum()
loss.backward()
self.assertEqual(query.grad[:, :, M:, :].sum(), 0)
else:
out = flex(
query,
key,
value,
block_mask=block_mask,
enable_gqa=True,
return_lse=False,
)
self.assertEqual(out[:, :, M:, :].sum(), 0)
@supported_platform
def test_windowed_no_mask_vs_sdpa(self, device):
score_mod = _generate_windowed(1000)
attention = functools.partial(flex_attention, score_mod=score_mod)
sdpa_mask = _get_windowed_sdpa_mask(8, S, 1000)
sdpa_attention = functools.partial(
torch.nn.functional.scaled_dot_product_attention, attn_mask=sdpa_mask
)
self.run_test_with_call(
attention, sdpa_attention, Q_H=16, KV_H=16, Q_S=8, device=device
)
@supported_platform
def test_windowed_full_mask_vs_sdpa(self, device):
def mask_mod(b, h, q, kv):
return q + 1000 >= kv
score_mod = _generate_windowed(1000)
block_mask = create_block_mask(mask_mod, 1, 1, 8, S, device=device)
attention = functools.partial(
flex_attention, block_mask=block_mask, score_mod=score_mod
)
sdpa_mask = _get_windowed_sdpa_mask(8, S, 1000)
sdpa_attention = functools.partial(
torch.nn.functional.scaled_dot_product_attention, attn_mask=sdpa_mask
)
self.run_test_with_call(
attention, sdpa_attention, Q_H=16, KV_H=16, Q_S=8, device=device
)
@supported_platform
def test_windowed_partial_block_vs_sdpa(self, device):
def mask_mod(b, h, q, kv):
return q + 1000 >= kv
block_mask = create_block_mask(mask_mod, 1, 1, 8, S, device=device)
attention = functools.partial(flex_attention, block_mask=block_mask)
sdpa_mask = _get_windowed_sdpa_mask(8, S, 1000)
sdpa_attention = functools.partial(
torch.nn.functional.scaled_dot_product_attention, attn_mask=sdpa_mask
)
self.run_test_with_call(
attention, sdpa_attention, Q_H=16, KV_H=16, Q_S=8, device=device
)
@supported_platform
def test_windowed_no_mask_vs_sdpa_paged_attention(self, device):
score_mod = _generate_windowed(1000)
sdpa_mask = _get_windowed_sdpa_mask(8, S, 1000)
self.run_test_with_call_paged_attention(
score_mod, None, sdpa_mask, Q_H=16, KV_H=16, Q_S=8, device=device
)
@supported_platform
def test_windowed_full_mask_vs_sdpa_paged_attention(self, device):
def mask_mod(b, h, q, kv):
return q + 1000 >= kv
score_mod = _generate_windowed(1000)
sdpa_mask = _get_windowed_sdpa_mask(8, S, 1000)
self.run_test_with_call_paged_attention(
score_mod, mask_mod, sdpa_mask, Q_H=16, KV_H=16, Q_S=8, device=device
)
@supported_platform
def test_windowed_partial_block_vs_sdpa_paged_attention(self, device):
def mask_mod(b, h, q, kv):
return q + 1000 >= kv
sdpa_mask = _get_windowed_sdpa_mask(8, S, 1000)
self.run_test_with_call_paged_attention(
None, mask_mod, sdpa_mask, Q_H=16, KV_H=16, Q_S=8, device=device
)
@supported_platform
@unittest.skipIf(SKIP_UT_ON_CPU, "Skip on CPU as not supported")
@common_utils.parametrize("dtype", test_dtypes)
@common_utils.parametrize("score_mod", [_identity, _causal])
def test_logsumexp_correctness(self, dtype, score_mod):
make_kv = functools.partial(
torch.randn,
(B, Hkv, S, D),
dtype=dtype,
device="cuda",
requires_grad=True,
)
make_q = functools.partial(
torch.randn,
(B, Hkv, Hq // Hkv, D),
dtype=dtype,
device="cuda",
requires_grad=True,
)
q, k, v = make_q(), make_kv(), make_kv()
@torch.compile
def sdpa_hop(q, k, v, score_mod):
return flex_attention(q, k, v, score_mod, return_lse=True)
@torch.compile(backend="aot_eager")
def eager_sdpa_hop(q, k, v, score_mod):
return flex_attention(q, k, v, score_mod, return_lse=True)
ref_out, ref_lse = eager_sdpa_hop(
q.to(torch.float64),
k.to(torch.float64),
v.to(torch.float64),
score_mod,
)
compiled_out, compiled_lse = sdpa_hop(q, k, v, score_mod)
self.assertTrue(ref_lse.dtype == torch.float64)
self.assertTrue(compiled_lse.dtype == torch.float32)
tolerance = Tolerances(atol=2e-2, rtol=2e-2)
torch.testing.assert_close(
ref_out.to(dtype=torch.float32),
compiled_out.to(dtype=torch.float32),
atol=tolerance.atol,
rtol=tolerance.rtol,
)
torch.testing.assert_close(
ref_lse.to(dtype=torch.float32),
compiled_lse.to(dtype=torch.float32),
atol=tolerance.atol,
rtol=tolerance.rtol,
)
@supported_platform
@unittest.skipIf(SKIP_UT_ON_CPU, "Skip on CPU as not supported")
def test_logsumexp_only_return(self):
make_q = functools.partial(
torch.randn,
(B, Hkv, Hq // Hkv, D),
dtype=torch.float32,
device="cuda",
requires_grad=True,
)
make_kv = functools.partial(
torch.randn,
(B, Hkv, S, D),
dtype=torch.float32,
device="cuda",
requires_grad=True,
)
q, k, v = make_q(), make_kv(), make_kv()
@torch.compile
def func(q, k, v, score_mod):
_, lse = flex_attention(q, k, v, score_mod, return_lse=True)
lse_2 = lse * 2
return lse_2
_, code = run_and_get_code(func, q, k, v, _identity)
# Ensure that we're still generating the flexattention kernel
FileCheck().check_count(".run(primals_1, primals_2, primals_3", 1, True).run(
code[0]
)
@supported_platform
def test_non_sparse_mulitple_block_size(self, device):
def generate_causal_offset(offset: torch.Tensor):
def causal_offset_mask(b, h, q_idx, kv_idx):
return (offset + q_idx) >= kv_idx
return causal_offset_mask
def noop(score, b, h, q_idx, kv_idx): # noqa: F841
return score
mod = generate_causal_offset(
torch.tensor(192, device=device, dtype=torch.int32)
)
block_mask = create_block_mask(mod, 1, 1, 1, 65, device=device)
self.run_test(
score_mod=None,
dtype=torch.float32,
block_mask=block_mask,
Q_B=1,
Q_H=1,
Q_S=1,
Q_D=16,
KV_B=1,
KV_H=1,
KV_S=65,
V_D=16,
device=device,
)
self.run_test_with_paged_attention(
score_mod=None,
dtype=torch.float32,
block_mask=block_mask,
Q_B=1,
Q_H=1,
Q_S=1,
QK_D=16,
KV_B=1,
KV_H=1,
KV_S=65,
V_D=16,
device=device,
)
@supported_platform
def test_do_not_trigger_dynamic_shapes_on_empty_block_mask(self, device):
torch._dynamo.reset()
H = Hq
q = torch.randn(B, H, 1, D, device=device)
for i in range(5):
k = torch.randn(B, H, S + i, D, device=device)
v = torch.randn(B, H, S + i, D, device=device)
compiled_flex_attention = torch.compile(flex_attention)
ref = flex_attention(q, k, v)
res = compiled_flex_attention(q, k, v)
tolerance = Tolerances(atol=2e-1, rtol=2e-1)
torch.testing.assert_close(
ref, res, atol=tolerance.atol, rtol=tolerance.rtol
)
# Ensure no more re-compilation after the second automatic dynamic shape version.
if i == 0:
self.assertEqual(torch._dynamo.utils.counters["frames"]["ok"], 2)
else:
self.assertEqual(torch._dynamo.utils.counters["frames"]["ok"], 4)
@supported_platform
@common_utils.parametrize("dtype", test_dtypes_fast)
def test_larger_block_mask_bug(self, device, dtype):
def mask_mod(b, h, q_idx, kv_idx):
return q_idx >= kv_idx
mask_2 = create_block_mask(
mask_mod=mask_mod,
B=2,
H=None,
Q_LEN=2,
KV_LEN=2,
device=device,
)
# Compile flex attention
flex_attention_compiled = torch.compile(flex_attention, dynamic=False)
# Create input tensors
shape = (2, 1, 2, 16)
q = torch.normal(0.0, 3.0, shape, device=device, dtype=dtype)
k = torch.normal(0.0, 3.0, shape, device=device, dtype=dtype)
v = torch.normal(0.0, 3.0, shape, device=device, dtype=dtype)
eager = flex_attention(q, k, v, block_mask=mask_2)
out = flex_attention_compiled(q, k, v, block_mask=mask_2)
torch.testing.assert_close(eager, out, atol=5e-3, rtol=5e-3)
@common_utils.parametrize("dtype", test_dtypes_fast)
@common_utils.parametrize("score_mod", test_score_mods)
@supported_platform
def test_decode_at_different_input_position(
self, device, dtype: torch.dtype, score_mod: Callable
):
n_pages, page_size, max_batch_size, max_seq_len = 32, 64, 4, 512
n_heads, head_dim = 4, 16
def causal_mask(b, h, q, kv):
return q >= kv
block_mask = create_block_mask(
causal_mask,
max_batch_size,
1,
max_seq_len,
max_seq_len,
device=device,
BLOCK_SIZE=page_size,
)
# init 4 requests with different prefill length
prefill_length = [5, 98, 47, 194]
queries, keys, values = [], [], []
for seq_len in prefill_length:
q = torch.randn(
1,
n_heads,
1,
head_dim,
device=device,
dtype=dtype,
requires_grad=False,
)
k = torch.randn(
1,
n_heads,
seq_len,
head_dim,
device=device,
dtype=dtype,
requires_grad=False,
)
v = torch.randn(
1,
n_heads,
seq_len,
head_dim,
device=device,
dtype=dtype,
requires_grad=False,
)
queries.append(q)
keys.append(k)
values.append(v)
# get ground truth output
ref_outs, golden_outs = [], []
for q, k, v in zip(queries, keys, values):
q_ref, k_ref, v_ref = query_key_value_clones(q, k, v)
q_gold, k_gold, v_gold = query_key_value_clones(q, k, v, torch.float64)
slice_block_mask = block_mask._adjust(1, k_ref.shape[2])
slice_block_mask.seq_lengths = (1, k_ref.shape[2])
ref_out = flex_attention(
q_ref, k_ref, v_ref, score_mod, slice_block_mask, enable_gqa=False
)
golden_out = flex_attention(
q_gold, k_gold, v_gold, score_mod, slice_block_mask, enable_gqa=False
)
ref_outs.append(ref_out)
golden_outs.append(golden_out)
ref_outs = torch.cat(ref_outs)
golden_outs = torch.cat(golden_outs)
# init paged attention
paged_cache = PagedAttention(n_pages, page_size, max_batch_size, device=device)
batch_reserve(paged_cache, torch.tensor([100, 200, 50, 300], device=device))
batch_reserve(paged_cache, torch.tensor([100, 512, 300, 300], device=device))
batch_reserve(paged_cache, torch.tensor([512, 512, 300, 300], device=device))
batch_reserve(paged_cache, torch.tensor([512, 512, 512, 300], device=device))
batch_reserve(paged_cache, torch.tensor([512, 512, 512, 512], device=device))
# allocate paged kv cache
MAX_CACHED_SEQ_LEN = n_pages * page_size
k_cache = torch.zeros(
1,
n_heads,
MAX_CACHED_SEQ_LEN,
head_dim,
device=device,
dtype=dtype,
)
v_cache = torch.zeros(
1,
n_heads,
MAX_CACHED_SEQ_LEN,
head_dim,
device=device,
dtype=dtype,
)
# prefill paged kv cache
for i, seq_len in enumerate(prefill_length):
batch_idx = torch.tensor([i], device=device, dtype=torch.int32)
input_pos = torch.arange(seq_len, device=device, dtype=torch.int32).view(
1, seq_len
)
paged_cache.assign(
batch_idx, input_pos, keys[i], values[i], k_cache, v_cache
)
# get paged out and check correctness
batch_idx = torch.arange(max_batch_size, device=device, dtype=torch.int32)
input_pos = torch.tensor(prefill_length, device=device, dtype=torch.int32).view(
max_batch_size, 1
)
new_block_mask = paged_cache.convert_logical_block_mask(block_mask)
new_block_mask.seq_lengths = (1, new_block_mask.seq_lengths[1])
compiled_sdpa = torch.compile(
create_attention(
paged_cache.get_score_mod(score_mod), new_block_mask, enable_gqa=False
)
)
paged_out = compiled_sdpa(
torch.cat(queries, 0), k_cache, v_cache, block_mask=new_block_mask
)
with torch.no_grad():
dtype = paged_out.dtype
if dtype == torch.float32:
fudge_factor = 10.0
else:
fudge_factor = 1.1
# Checkout output
self._check_equal(golden_outs, ref_outs, paged_out, fudge_factor, "Out")
instantiate_device_type_tests(TestFlexDecoding, globals(), only_for=test_device)
if __name__ == "__main__":
from torch._inductor.test_case import run_tests
run_tests()