sglang_v0.5.2/sglang/sgl-kernel/tests/test_flash_attention.py

1369 lines
51 KiB
Python

# Adapted from https://github.com/Dao-AILab/flash-attention/blob/main/hopper/test_flash_attn.py
import itertools
import math
from typing import Optional
import pytest
import torch
import torch.nn.functional as F
from einops import rearrange, repeat
apply_rotary_emb = None
def is_hopper():
# Only Hopper supports different V headdim
return torch.cuda.get_device_properties(0).major == 9
def is_fa3_supported(device=None) -> bool:
# There some fa3 FYI
# FA3 can fail without a enough shared memory for a some shapes, such as higher
# hidden_dim or some special cases.
# Right now, fa3 is supported for sm80/sm87 and sm86/sm89. The main different
# Between sm80/sm87 and sm86/sm89 is the shared memory size. you can follow the link below for more information
# https://docs.nvidia.com/cuda/cuda-c-programming-guide/#shared-memory-8-x
# And for sgl-kernel right now, we can build fa3 on sm80/sm86/sm89/sm90a.
# That means if you use A100/A*0/L20/L40/L40s/4090 you can use fa3.
return (torch.version.cuda >= "12.3") and (
torch.cuda.get_device_capability(device)[0] == 9
or torch.cuda.get_device_capability(device)[0] == 8
)
DISABLE_BACKWARD = True
# For CI test, we close them to True.
# DISABLE_SPLIT = os.getenv("FLASH_ATTENTION_DISABLE_SPLIT", "FALSE") == "TRUE"
# DISABLE_PAGEDKV = os.getenv("FLASH_ATTENTION_DISABLE_PAGEDKV", "FALSE") == "TRUE"
# DISABLE_APPENDKV = os.getenv("FLASH_ATTENTION_DISABLE_APPENDKV", "FALSE") == "TRUE"
# DISABLE_LOCAL = os.getenv("FLASH_ATTENTION_DISABLE_LOCAL", "FALSE") == "TRUE"
# DISABLE_SOFTCAP = os.getenv("FLASH_ATTENTION_DISABLE_SOFTCAP", "FALSE") == "TRUE"
# DISABLE_PACKGQA = os.getenv("FLASH_ATTENTION_DISABLE_PACKGQA", "FALSE") == "TRUE"
# DISABLE_FP16 = os.getenv("FLASH_ATTENTION_DISABLE_FP16", "FALSE") == "TRUE"
# DISABLE_FP8 = (
# os.getenv("FLASH_ATTENTION_DISABLE_FP8", "FALSE") == "TRUE"
# or torch.cuda.get_device_capability("cuda")[0] < 9
# )
DISABLE_SPLIT = False
DISABLE_PAGEDKV = True
DISABLE_APPENDKV = False
DISABLE_LOCAL = False
DISABLE_SOFTCAP = True
DISABLE_PACKGQA = False
DISABLE_FP16 = True
DISABLE_FP8 = True
# Adapted from https://github.com/Dao-AILab/flash-attention/blob/main/hopper/padding.py
def unpad_input(hidden_states, attention_mask, unused_mask=None):
"""
Arguments:
hidden_states: (batch, seqlen, ...)
attention_mask: (batch, seqlen), bool / int, 1 means valid and 0 means not valid.
unused_mask: (batch, seqlen), bool / int, 1 means the element is allocated but unused.
Return:
hidden_states: (total_nnz, ...), where total_nnz = number of tokens selected in attention_mask + unused_mask.
indices: (total_nnz), the indices of masked tokens from the flattened input sequence.
cu_seqlens: (batch + 1), the cumulative sequence lengths, used to index into hidden_states.
max_seqlen_in_batch: int
seqused: (batch), returns the number of tokens selected in attention_mask + unused_mask.
"""
all_masks = (
(attention_mask + unused_mask) if unused_mask is not None else attention_mask
)
seqlens_in_batch = all_masks.sum(dim=-1, dtype=torch.int32)
used_seqlens_in_batch = attention_mask.sum(dim=-1, dtype=torch.int32)
indices = torch.nonzero(all_masks.flatten(), as_tuple=False).flatten()
max_seqlen_in_batch = seqlens_in_batch.max().item()
cu_seqlens = F.pad(torch.cumsum(seqlens_in_batch, dim=0, dtype=torch.int32), (1, 0))
# TD [2022-03-04] We don't want to index with a bool mask, because Pytorch will expand the
# bool mask, then call nonzero to get the indices, then index with those. The indices is @dim
# times larger than it needs to be, wasting memory. It's faster and more memory-efficient to
# index with integer indices.
return (
rearrange(hidden_states, "b s ... -> (b s) ...")[indices],
indices,
cu_seqlens,
max_seqlen_in_batch,
used_seqlens_in_batch,
)
def generate_random_padding_mask(
max_seqlen, batch_size, device, mode="random", zero_lengths=False
):
assert mode in ["full", "random", "third"]
if mode == "full":
lengths = torch.full(
(batch_size, 1), max_seqlen, device=device, dtype=torch.int32
)
elif mode == "random":
lengths = torch.randint(
max(0 if zero_lengths else 1, max_seqlen - 20),
max_seqlen + 1,
(batch_size, 1),
device=device,
)
elif mode == "third":
lengths = torch.randint(
max_seqlen // 3, max_seqlen + 1, (batch_size, 1), device=device
)
if zero_lengths:
# Generate zero-lengths every 5 batches and the last batch.
for i in range(batch_size):
if i % 5 == 0:
lengths[i] = 0
lengths[-1] = 0
padding_mask = (
repeat(torch.arange(max_seqlen, device=device), "s -> b s", b=batch_size)
< lengths
)
return padding_mask
def pad_input(hidden_states, indices, batch, seqlen):
"""
Arguments:
hidden_states: (total_nnz, ...), where total_nnz = number of tokens in selected in attention_mask.
indices: (total_nnz), the indices that represent the non-masked tokens of the original padded input sequence.
batch: int, batch size for the padded sequence.
seqlen: int, maximum sequence length for the padded sequence.
Return:
hidden_states: (batch, seqlen, ...)
"""
dim = hidden_states.shape[1:]
output = torch.zeros(
(batch * seqlen), *dim, device=hidden_states.device, dtype=hidden_states.dtype
)
output[indices] = hidden_states
return rearrange(output, "(b s) ... -> b s ...", b=batch)
def construct_local_mask(
seqlen_q,
seqlen_k,
window_size=(-1, -1), # -1 means infinite window size
sink_token_length=0,
query_padding_mask=None,
key_padding_mask=None,
key_leftpad=None,
device=None,
):
row_idx = rearrange(
torch.arange(seqlen_q, device=device, dtype=torch.long), "s -> s 1"
)
col_idx = torch.arange(seqlen_k, device=device, dtype=torch.long)
if key_leftpad is not None:
key_leftpad = rearrange(key_leftpad, "b -> b 1 1 1")
col_idx = repeat(col_idx, "s -> b 1 1 s", b=key_leftpad.shape[0])
col_idx = torch.where(col_idx >= key_leftpad, col_idx - key_leftpad, 2**32)
sk = (
seqlen_k
if key_padding_mask is None
else rearrange(key_padding_mask.sum(-1), "b -> b 1 1 1")
)
sq = (
seqlen_q
if query_padding_mask is None
else rearrange(query_padding_mask.sum(-1), "b -> b 1 1 1")
)
if window_size[0] < 0:
return col_idx > row_idx + sk - sq + window_size[1]
else:
sk = torch.full_like(col_idx, seqlen_k) if key_padding_mask is None else sk
return torch.logical_or(
col_idx > torch.minimum(row_idx + sk - sq + window_size[1], sk),
torch.logical_and(
col_idx < row_idx + sk - sq - window_size[0],
col_idx >= sink_token_length,
),
)
def attention_ref(
q,
k,
v,
query_padding_mask=None,
key_padding_mask=None,
key_leftpad=None,
attn_bias=None,
dropout_p=0.0,
dropout_mask=None,
causal=False,
qv=None,
q_descale=None,
k_descale=None,
v_descale=None,
window_size=(-1, -1), # -1 means infinite window size
sink_token_length=0,
sinks: Optional[torch.Tensor] = None,
softcap=0.0,
upcast=True,
reorder_ops=False,
intermediate_dtype=None,
):
"""
Arguments:
q: (batch_size, seqlen_q, nheads, head_dim)
k: (batch_size, seqlen_k, nheads, head_dim)
v: (batch_size, seqlen_k, nheads, head_dim_v)
qv: (batch_size, seqlen_q, nheads, head_dim_v)
query_padding_mask: (batch_size, seqlen_q)
key_padding_mask: (batch_size, seqlen_k)
attn_bias: broadcastable to (batch_size, nheads, seqlen_q, seqlen_k)
dropout_p: float
dropout_mask: (batch_size, nheads, seqlen_q, seqlen_k)
causal: whether to apply causal masking
upcast: whether to cast all inputs to fp32, do all computation in fp32, then cast
output back to fp16/bf16.
reorder_ops: whether to change the order of operations (scaling k instead of scaling k, etc.)
without changing the math. This is to estimate the numerical error from operation
reordering.
Output:
output: (batch_size, seqlen_q, nheads, head_dim_v)
attention: (batch_size, nheads, seqlen_q, seqlen_k), softmax after dropout
"""
if causal:
window_size = (window_size[0], 0)
dtype_og = q.dtype
if upcast:
q, k, v = q.float(), k.float(), v.float()
qv = qv.float() if qv is not None else None
if q_descale is not None:
q_descale = repeat(q_descale, "b h -> b 1 (h g) 1", g=q.shape[2] // k.shape[2])
q = (q.float() * q_descale).to(q.dtype)
qv = (qv.float() * q_descale).to(qv.dtype) if qv is not None else None
if k_descale is not None:
k = (k.float() * rearrange(k_descale, "b h -> b 1 h 1")).to(dtype=k.dtype)
if v_descale is not None:
v = (v.float() * rearrange(v_descale, "b h -> b 1 h 1")).to(dtype=v.dtype)
seqlen_q, seqlen_k = q.shape[1], k.shape[1]
k = repeat(k, "b s h d -> b s (h g) d", g=q.shape[2] // k.shape[2])
v = repeat(v, "b s h d -> b s (h g) d", g=q.shape[2] // v.shape[2])
d = q.shape[-1]
dv = v.shape[-1]
softmax_scale = 1.0 / math.sqrt(d if qv is None else d + dv)
if not reorder_ops:
scores = torch.einsum("bthd,bshd->bhts", q * softmax_scale, k)
else:
scores = torch.einsum("bthd,bshd->bhts", q, k * softmax_scale)
if qv is not None:
scores = scores + torch.einsum("bthd,bshd->bhts", qv * softmax_scale, v)
if softcap > 0:
scores = torch.tanh(scores / softcap) * softcap
if key_padding_mask is not None:
scores.masked_fill_(
rearrange(~key_padding_mask, "b s -> b 1 1 s"), float("-inf")
)
if window_size[0] >= 0 or window_size[1] >= 0:
local_mask = construct_local_mask(
seqlen_q,
seqlen_k,
window_size,
sink_token_length,
query_padding_mask,
key_padding_mask,
key_leftpad=key_leftpad,
device=q.device,
)
scores.masked_fill_(local_mask, float("-inf"))
if attn_bias is not None:
scores = scores + attn_bias
if sinks is None:
attention = torch.softmax(scores, dim=-1).to(v.dtype)
else:
scores_fp32 = scores.to(torch.float32)
logits_max = torch.amax(scores_fp32, dim=-1, keepdim=True)
sinks = rearrange(sinks, "h -> h 1 1")
logits_or_sinks_max = torch.maximum(sinks, logits_max)
unnormalized_scores = torch.exp(scores_fp32 - logits_or_sinks_max)
normalizer = unnormalized_scores.sum(dim=-1, keepdim=True) + torch.exp(
sinks - logits_or_sinks_max
)
attention = (unnormalized_scores / normalizer).to(v.dtype)
# We want to mask here so that the attention matrix doesn't have any NaNs
# Otherwise we'll get NaN in dV
if query_padding_mask is not None:
attention = attention.masked_fill(
rearrange(~query_padding_mask, "b s -> b 1 s 1"), 0.0
)
# Without this we might get NaN in dv
if key_padding_mask is not None:
attention = attention.masked_fill(
rearrange(~key_padding_mask, "b s -> b 1 1 s"), 0.0
)
# Some rows might be completely masked out so we fill them with zero instead of NaN
if window_size[0] >= 0 or window_size[1] >= 0:
attention = attention.masked_fill(
torch.all(local_mask, dim=-1, keepdim=True), 0.0
)
dropout_scaling = 1.0 / (1 - dropout_p)
# attention_drop = attention.masked_fill(~dropout_mask, 0.0) * dropout_scaling
# output = torch.einsum('bhts,bshd->bthd', attention_drop , v)
if dropout_mask is not None:
attention_drop = attention.masked_fill(~dropout_mask, 0.0)
else:
attention_drop = attention
if intermediate_dtype is not None:
attention_drop = attention_drop.to(intermediate_dtype).to(attention_drop.dtype)
output = torch.einsum("bhts,bshd->bthd", attention_drop, v * dropout_scaling)
if query_padding_mask is not None:
output.masked_fill_(rearrange(~query_padding_mask, "b s -> b s 1 1"), 0.0)
return output.to(dtype=dtype_og), attention.to(dtype=dtype_og)
def generate_qkv(
q,
k,
v,
query_padding_mask=None,
key_padding_mask=None,
kvpacked=False,
qkvpacked=False,
add_unused_qkv=False,
query_unused_mask=None,
key_unused_mask=None,
):
"""
Arguments:
q: (batch_size, seqlen_q, nheads, d)
k: (batch_size, seqlen_k, nheads_k, d)
v: (batch_size, seqlen_k, nheads_k, d)
query_padding_mask: (batch_size, seqlen), bool
key_padding_mask: (batch_size, seqlen), bool
"""
assert not (kvpacked and qkvpacked)
batch_size, seqlen_q, nheads, d = q.shape
_, seqlen_k, nheads_k, _ = k.shape
assert k.shape == (batch_size, seqlen_k, nheads_k, d)
assert v.shape == (batch_size, seqlen_k, nheads_k, d)
if query_unused_mask is not None or key_unused_mask is not None:
assert not kvpacked
assert not qkvpacked
if query_padding_mask is not None:
q_unpad, indices_q, cu_seqlens_q, max_seqlen_q, seqused_q = unpad_input(
q,
query_padding_mask,
query_unused_mask,
)
output_pad_fn = lambda output_unpad: pad_input(
output_unpad, indices_q, batch_size, seqlen_q
)
else:
q_unpad = rearrange(q, "b s h d -> (b s) h d")
cu_seqlens_q = torch.arange(
0,
(batch_size + 1) * seqlen_q,
step=seqlen_q,
dtype=torch.int32,
device=q_unpad.device,
)
seqused_q = None
max_seqlen_q = seqlen_q
output_pad_fn = lambda output_unpad: rearrange(
output_unpad, "(b s) h d -> b s h d", b=batch_size
)
if key_padding_mask is not None:
k_unpad, indices_k, cu_seqlens_k, max_seqlen_k, seqused_k = unpad_input(
k, key_padding_mask, key_unused_mask
)
v_unpad, _, _, _, _ = unpad_input(v, key_padding_mask, key_unused_mask)
else:
k_unpad = rearrange(k, "b s h d -> (b s) h d")
v_unpad = rearrange(v, "b s h d -> (b s) h d")
cu_seqlens_k = torch.arange(
0,
(batch_size + 1) * seqlen_k,
step=seqlen_k,
dtype=torch.int32,
device=k_unpad.device,
)
seqused_k = None
max_seqlen_k = seqlen_k
if qkvpacked:
assert (query_padding_mask == key_padding_mask).all()
assert nheads == nheads_k
qkv_unpad = torch.stack([q_unpad, k_unpad, v_unpad], dim=1)
qkv = torch.stack([q, k, v], dim=2)
if query_padding_mask is not None:
dqkv_pad_fn = lambda dqkv_unpad: pad_input(
dqkv_unpad, indices_q, batch_size, seqlen_q
)
else:
dqkv_pad_fn = lambda dqkv_unpad: rearrange(
dqkv_unpad, "(b s) t h d -> b s t h d", b=batch_size
)
return (
qkv_unpad.detach().requires_grad_(),
cu_seqlens_q,
max_seqlen_q,
qkv.detach().requires_grad_(),
output_pad_fn,
dqkv_pad_fn,
)
elif kvpacked:
kv_unpad = torch.stack([k_unpad, v_unpad], dim=1)
kv = torch.stack([k, v], dim=2)
dq_pad_fn = output_pad_fn
if key_padding_mask is not None:
dkv_pad_fn = lambda dkv_unpad: pad_input(
dkv_unpad, indices_k, batch_size, seqlen_k
)
else:
dkv_pad_fn = lambda dkv_unpad: rearrange(
dkv_unpad, "(b s) t h d -> b s t h d", b=batch_size
)
return (
q_unpad.detach().requires_grad_(),
kv_unpad.detach().requires_grad_(),
cu_seqlens_q,
cu_seqlens_k,
max_seqlen_q,
max_seqlen_k,
q.detach().requires_grad_(),
kv.detach().requires_grad_(),
output_pad_fn,
dq_pad_fn,
dkv_pad_fn,
)
else:
dq_pad_fn = output_pad_fn
if key_padding_mask is not None:
dk_pad_fn = lambda dk_unpad: pad_input(
dk_unpad, indices_k, batch_size, seqlen_k
)
else:
dk_pad_fn = lambda dk_unpad: rearrange(
dk_unpad, "(b s) h d -> b s h d", b=batch_size
)
return (
q_unpad.detach().requires_grad_(),
k_unpad.detach().requires_grad_(),
v_unpad.detach().requires_grad_(),
cu_seqlens_q,
cu_seqlens_k,
seqused_q,
seqused_k,
max_seqlen_q,
max_seqlen_k,
q.detach().requires_grad_(),
k.detach().requires_grad_(),
v.detach().requires_grad_(),
output_pad_fn,
dq_pad_fn,
dk_pad_fn,
)
@pytest.mark.skipif(
not is_fa3_supported(),
reason="flash_attn at sgl-kernel is only supported on sm90 or sm80",
)
# @pytest.mark.parametrize("dtype", [torch.float16, torch.bfloat16, torch.float8_e4m3fn])
@pytest.mark.parametrize(
"dtype", [torch.bfloat16] + ([torch.float8_e4m3fn] if not DISABLE_FP8 else [])
)
# @pytest.mark.parametrize("dtype", [torch.bfloat16])
# @pytest.mark.parametrize("dtype", [torch.float8_e4m3fn])
@pytest.mark.parametrize("mha_type", ["mha", "mqa", "gqa"])
# @pytest.mark.parametrize("mha_type", ["mha"])
@pytest.mark.parametrize("has_sink", [False, True])
# @pytest.mark.parametrize("has_sink", [False])
@pytest.mark.parametrize("new_kv", [False] + ([True] if not DISABLE_APPENDKV else []))
# @pytest.mark.parametrize("new_kv", [True])
# @pytest.mark.parametrize(
# "causal,local",
# [(False, False), (True, False)] + ([(False, True)] if not DISABLE_LOCAL else []),
# )
# @pytest.mark.parametrize("causal,local", [(False, False), (True, False)])
@pytest.mark.parametrize("causal,local", [(False, False)])
@pytest.mark.parametrize(
"seqlen_new_eq_seqlen_q", [True, False] if not DISABLE_APPENDKV else [True]
)
# @pytest.mark.parametrize("seqlen_new_eq_seqlen_q", [True])
# @pytest.mark.parametrize("has_rotary_seqlens", [False, True])
@pytest.mark.parametrize("has_rotary_seqlens", [False])
@pytest.mark.parametrize(
"rotary_interleaved", [False, True] if not DISABLE_APPENDKV else [False]
)
# @pytest.mark.parametrize("rotary_interleaved", [True])
@pytest.mark.parametrize(
"rotary_fraction",
(
[0.0, 0.5, 1.0]
if (not DISABLE_APPENDKV) and (apply_rotary_emb is not None)
else [0.0]
),
)
# @pytest.mark.parametrize("rotary_fraction", [0.0])
@pytest.mark.parametrize(
"page_size", [None] + ([1, 4, 128] if not DISABLE_PAGEDKV else [])
)
# @pytest.mark.parametrize("page_size", [None])
# @pytest.mark.parametrize("has_leftpad", [False, True])
@pytest.mark.parametrize("has_leftpad", [False])
# @pytest.mark.parametrize("has_batch_idx", [False, True])
@pytest.mark.parametrize("has_batch_idx", [False])
# @pytest.mark.parametrize("varlen_q", [False, True])
@pytest.mark.parametrize("varlen_q", [False])
# @pytest.mark.parametrize("d", [32, 59, 64, 80, 128, 256])
# @pytest.mark.parametrize("d", [32, 64, 96, 128, 160, 192, 224, 256])
# @pytest.mark.parametrize('d', [32, 40, 64, 80, 96, 128, 160, 192])
# @pytest.mark.parametrize('d', [56, 80])
@pytest.mark.parametrize("d", [64])
# @pytest.mark.parametrize("d", [192])
@pytest.mark.parametrize(
"seqlen_q,seqlen_k",
[
(1, 128),
(1, 339),
(3, 1024),
(64, 800),
(64, 256),
(3, 799),
(64, 2048),
(16, 20000),
# (1, 128 * 1024),
# (16, 128 * 1024),
(128, 128),
(256, 512), # To test appending KV with more than 1 block
(2048, 3577), # Enough tile to test persistent scheduler
],
)
# @pytest.mark.parametrize('seqlen_q,seqlen_k', [(256, 128)])
def test_flash_attn_kvcache(
seqlen_q,
seqlen_k,
d,
varlen_q,
has_batch_idx,
has_leftpad,
page_size,
rotary_fraction,
rotary_interleaved,
has_rotary_seqlens,
seqlen_new_eq_seqlen_q,
causal,
local,
new_kv,
mha_type,
dtype,
has_sink,
):
from sgl_kernel.flash_attn import flash_attn_with_kvcache
if page_size is not None and seqlen_k % page_size != 0:
pytest.skip()
if seqlen_q > seqlen_k and new_kv:
pytest.skip()
if not new_kv and rotary_fraction > 0.0:
pytest.skip()
if rotary_fraction == 0.0 and has_rotary_seqlens:
pytest.skip()
device = "cuda"
# set seed
torch.random.manual_seed(0)
batch_size = 5
# batch_size = 1
batch_size_cache = batch_size if not has_batch_idx else batch_size * 2
nheads = 6
# nheads = 1
# rotary_dim must be a multiple of 16, and must be <= d
rotary_dim = math.floor(int(rotary_fraction * d) / 16) * 16
nheads_k = nheads if mha_type == "mha" else (1 if mha_type == "mqa" else 3)
assert nheads % nheads_k == 0
dtype_ref = torch.bfloat16 if dtype == torch.float8_e4m3fn else dtype
dv_vals = [128, d] if d > 128 and d <= 192 else ([256, 512, d] if d <= 64 else [d])
if has_sink:
sinks = torch.randn(nheads, dtype=torch.bfloat16, device=device)
else:
sinks = None
if dtype == torch.float8_e4m3fn or not is_hopper():
# for fp8 and ampere arch, we not support v head dim != qk head dim
dv_vals = [d]
for dv in dv_vals:
has_qv = d == 64 and dv >= 256
q = (
torch.randn(batch_size, seqlen_q, nheads, d, device=device, dtype=dtype_ref)
.to(dtype)
.to(dtype_ref)
)
if has_qv:
qv = (
torch.randn(
batch_size, seqlen_q, nheads, dv, device=device, dtype=dtype_ref
)
.to(dtype)
.to(dtype_ref)
)
else:
qv = None
if varlen_q:
query_padding_mask = generate_random_padding_mask(
seqlen_q, batch_size, device, mode="random"
)
q_unpad, indices_q, cu_seqlens_q, max_seqlen_q, *rest = unpad_input(
q, query_padding_mask
)
output_pad_fn = lambda output_unpad: pad_input(
output_unpad, indices_q, batch_size, seqlen_q
)
qv_unpad = (
rearrange(qv, "b s ... -> (b s) ...")[indices_q] if has_qv else None
)
else:
query_padding_mask = None
q_unpad = q
qv_unpad = qv
cu_seqlens_q, max_seqlen_q = None, None
# Put window_size after QKV randn so that window_size changes from test to test
window_size = (-1, -1) if not local else torch.randint(0, seqlen_k, (2,))
seqlen_new = (
seqlen_q
if seqlen_new_eq_seqlen_q
else torch.randint(1, seqlen_q + 1, (1,)).item()
)
cu_seqlens_k_new = None
key_new_padding_mask = None
if new_kv:
k = (
torch.randn(
batch_size, seqlen_new, nheads_k, d, device=device, dtype=dtype_ref
)
.to(dtype)
.to(dtype_ref)
)
v = (
torch.randn(
batch_size, seqlen_new, nheads_k, dv, device=device, dtype=dtype_ref
)
.to(dtype)
.to(dtype_ref)
)
if varlen_q: # k & v are also varlen
key_new_padding_mask = generate_random_padding_mask(
seqlen_new, batch_size, device, mode="random"
)
k_unpad, indices_k, cu_seqlens_k_new, *rest = unpad_input(
k, key_new_padding_mask
)
v_unpad, *rest = unpad_input(v, key_new_padding_mask)
else:
k_unpad, v_unpad = k, v
else:
k, v, k_unpad, v_unpad = None, None, None, None
if page_size is None:
k_cache = (
torch.randn(
batch_size_cache,
seqlen_k,
nheads_k,
d,
device=device,
dtype=dtype_ref,
)
.to(dtype)
.to(dtype_ref)
)
v_cache = (
torch.randn(
batch_size_cache,
seqlen_k,
nheads_k,
dv,
device=device,
dtype=dtype_ref,
)
.to(dtype)
.to(dtype_ref)
)
page_table = None
else:
(
k_cache,
v_cache,
page_table,
k_cache_paged,
v_cache_paged,
num_blocks,
) = _generate_block_kvcache(
seqlen_k,
page_size,
batch_size_cache,
nheads_k,
d,
dv,
device,
dtype,
dtype_ref,
)
cache_seqlens = torch.randint(
0 if new_kv else 1,
# If we don't use seqlen_q in the case of causal and rotary, cos/sin won't be long enough
(
(
seqlen_k
- (seqlen_q if (causal or local) and rotary_dim > 1 else seqlen_new)
+ 1
)
if new_kv
else (seqlen_k + 1)
),
(batch_size,),
dtype=torch.int32,
device=device,
)
if has_leftpad:
cache_leftpad = torch.cat(
[
(
torch.randint(
0,
cache_seqlens[i].item(),
(1,),
dtype=torch.int32,
device=device,
)
if cache_seqlens[i].item() > 0
else torch.zeros(1, dtype=torch.int32, device=device)
)
for i in range(batch_size)
]
)
else:
cache_leftpad = None
if has_batch_idx:
cache_batch_idx = torch.randperm(
batch_size_cache, dtype=torch.int32, device=device
)[:batch_size]
else:
cache_batch_idx = None
arange = rearrange(torch.arange(seqlen_k, device=device), "s -> 1 s")
cache_seqlens_expanded = rearrange(cache_seqlens, "b -> b 1")
if not new_kv:
key_padding_mask = arange < cache_seqlens_expanded
else:
k_new_seqlens = (
key_new_padding_mask.sum(-1, keepdims=True) if varlen_q else seqlen_new
)
key_padding_mask = arange < cache_seqlens_expanded + k_new_seqlens
if has_leftpad:
key_padding_mask = torch.logical_and(
key_padding_mask,
arange >= cache_leftpad.unsqueeze(-1).expand(-1, seqlen_k),
)
# cache_seqlens = torch.tensor([64], dtype=torch.int32, device=device)
rotary_seqlens = cache_seqlens if not has_rotary_seqlens else cache_seqlens // 2
if rotary_dim > 0:
angle = (
torch.rand(
seqlen_k if page_size is None else num_blocks * page_size,
rotary_dim // 2,
device=device,
)
* 2
* math.pi
)
cos = torch.cos(angle).to(dtype=dtype_ref).to(dtype).to(dtype_ref)
sin = torch.sin(angle).to(dtype=dtype_ref).to(dtype).to(dtype_ref)
if causal or local:
q_ro = apply_rotary_emb(
q,
cos,
sin,
seqlen_offsets=rotary_seqlens,
interleaved=rotary_interleaved,
)
else:
q_ro = rearrange(
apply_rotary_emb(
rearrange(q, "b s h d -> b 1 (s h) d"),
cos,
sin,
seqlen_offsets=rotary_seqlens,
interleaved=rotary_interleaved,
),
"b 1 (s h) d -> b s h d",
s=seqlen_q,
)
# q_ro = q
k_ro = apply_rotary_emb(
k,
cos,
sin,
seqlen_offsets=rotary_seqlens,
interleaved=rotary_interleaved,
)
else:
cos, sin = None, None
q_ro, k_ro = q, k
# k_cache[:, 64:] = -1
k_cache_ref = (
k_cache if not has_batch_idx else k_cache[cache_batch_idx]
).clone()
v_cache_ref = (
v_cache if not has_batch_idx else v_cache[cache_batch_idx]
).clone()
if new_kv:
update_mask = torch.logical_and(
cache_seqlens_expanded <= arange,
arange < cache_seqlens_expanded + k_new_seqlens,
)
k_to_update = rearrange(k_ro, "b s ... -> (b s) ...")
v_to_update = rearrange(v, "b s ... -> (b s) ...")
if varlen_q:
k_to_update = k_to_update[indices_k]
v_to_update = v_to_update[indices_k]
k_cache_ref[update_mask] = k_to_update
v_cache_ref[update_mask] = v_to_update
k_cache_rep = repeat(
k_cache_ref, "b s h d -> b s (h g) d", g=nheads // nheads_k
)
v_cache_rep = repeat(
v_cache_ref, "b s h d -> b s (h g) d", g=nheads // nheads_k
)
out_ref, _ = attention_ref(
q_ro,
k_cache_rep,
v_cache_rep,
query_padding_mask,
key_padding_mask,
causal=causal,
qv=qv,
window_size=window_size,
key_leftpad=cache_leftpad,
sinks=sinks,
)
out_pt, _ = attention_ref(
q_ro,
k_cache_rep,
v_cache_rep,
query_padding_mask,
key_padding_mask,
causal=causal,
qv=qv,
window_size=window_size,
upcast=False,
reorder_ops=True,
key_leftpad=cache_leftpad,
intermediate_dtype=dtype if dtype == torch.float8_e4m3fn else None,
sinks=sinks,
)
q = q.to(dtype)
q_unpad = q_unpad.to(dtype) if varlen_q else None
k_cache = k_cache.to(dtype)
v_cache = v_cache.to(dtype)
k_cache_paged = k_cache_paged.to(dtype) if page_size is not None else None
v_cache_paged = v_cache_paged.to(dtype) if page_size is not None else None
k = k.to(dtype) if k is not None else None
v = v.to(dtype) if v is not None else None
k_unpad = k_unpad.to(dtype) if k_unpad is not None else None
v_unpad = v_unpad.to(dtype) if v_unpad is not None else None
qv = qv.to(dtype) if qv is not None else None
qv_unpad = qv_unpad.to(dtype) if (varlen_q and qv is not None) else None
cos = cos.to(dtype) if cos is not None else None
sin = sin.to(dtype) if sin is not None else None
k_cache_saved = k_cache.clone() if page_size is None else k_cache_paged.clone()
v_cache_saved = v_cache.clone() if page_size is None else v_cache_paged.clone()
num_splits_vals = [1, 0] if not DISABLE_SPLIT else [1]
precompute_metadata_vals = [False]
for num_splits, precompute_metadata in itertools.product(
num_splits_vals, precompute_metadata_vals
):
scheduler_metadata = None
# Repeat to test metadata reuse
for _ in range(1 if not precompute_metadata else 2):
if page_size is None:
k_cache.copy_(k_cache_saved)
v_cache.copy_(v_cache_saved)
else:
k_cache_paged.copy_(k_cache_saved)
v_cache_paged.copy_(v_cache_saved)
out, lse, *rest = flash_attn_with_kvcache(
q if not varlen_q else q_unpad,
k_cache if page_size is None else k_cache_paged,
v_cache if page_size is None else v_cache_paged,
k if not new_kv or not varlen_q else k_unpad,
v if not new_kv or not varlen_q else v_unpad,
qv=qv if not varlen_q else qv_unpad,
rotary_cos=cos,
rotary_sin=sin,
cache_seqlens=cache_seqlens,
cache_batch_idx=cache_batch_idx,
cache_leftpad=cache_leftpad,
page_table=page_table,
cu_seqlens_q=cu_seqlens_q,
cu_seqlens_k_new=cu_seqlens_k_new,
max_seqlen_q=max_seqlen_q,
rotary_seqlens=rotary_seqlens,
causal=causal,
window_size=window_size,
rotary_interleaved=rotary_interleaved,
scheduler_metadata=scheduler_metadata,
num_splits=num_splits,
return_softmax_lse=True,
sinks=sinks,
)
if varlen_q:
out = output_pad_fn(out)
# out = flash_attn_with_kvcache(
# q, k_cache, v_cache, cache_seqlens=cache_seqlens, causal=causal, window_size=window_size
# )
# out = flash_attn_with_kvcache(q, k_cache, v_cache, causal=causal, window_size=window_size)
# qk = torch.einsum("bqhd,bkhd->bhqk", q, k_cache_ref)
# m = qk.amax(-1, keepdim=True)
# s_tmp = torch.exp((qk - m) / math.sqrt(d))
# o1 = torch.einsum('bhst,bthd->bshd', s_tmp, v_cache_ref)
# lse_ref = torch.logsumexp(qk / math.sqrt(d), -1)
# probs = torch.softmax(qk, dim=-1)
print(f"Output max diff: {(out - out_ref).abs().max().item()}")
print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
print(f"Pytorch max diff: {(out_pt - out_ref).abs().max().item()}")
print(f"Pytorch mean diff: {(out_pt - out_ref).abs().mean().item()}")
# breakpoint()
# Check that FlashAttention's numerical error is at most twice the numerical error
# of a Pytorch implementation.
if new_kv:
if page_size is None:
k_cache_select = (
k_cache.to(dtype_ref)
if not has_batch_idx
else k_cache.to(dtype_ref)[cache_batch_idx]
)
v_cache_select = (
v_cache.to(dtype_ref)
if not has_batch_idx
else v_cache.to(dtype_ref)[cache_batch_idx]
)
else:
k_cache_select = rearrange(
k_cache_paged.to(dtype_ref)[
(
page_table
if not has_batch_idx
else page_table[cache_batch_idx]
).flatten()
],
"(b nblocks) block_size ... -> b (nblocks block_size) ...",
b=batch_size,
)[:, :seqlen_k].to(dtype_ref)
v_cache_select = rearrange(
v_cache_paged.to(dtype_ref)[
(
page_table
if not has_batch_idx
else page_table[cache_batch_idx]
).flatten()
],
"(b nblocks) block_size ... -> b (nblocks block_size) ...",
b=batch_size,
)[:, :seqlen_k].to(dtype_ref)
k_cache_ref = k_cache_ref.to(dtype).to(dtype_ref)
v_cache_ref = v_cache_ref.to(dtype).to(dtype_ref)
if dtype is not torch.float8_e4m3fn:
assert torch.equal(v_cache_select, v_cache_ref)
else:
assert torch.allclose(
v_cache_select, v_cache_ref, rtol=1e-3, atol=1e-3
)
# breakpoint()
# if rotary_dim == 0 and dtype is not torch.float8_e4m3fn:
if rotary_dim == 0:
assert torch.equal(k_cache_select, k_cache_ref)
else:
# if not torch.allclose(k_cache_select, k_cache_ref, rtol=1e-3, atol=1e-3):
# breakpoint()
if dtype is not torch.float8_e4m3fn:
assert torch.allclose(
k_cache_select, k_cache_ref, rtol=1e-3, atol=1e-3
)
else:
assert torch.allclose(
k_cache_select, k_cache_ref, rtol=1e-1, atol=1e-1
)
mult = 4 if dtype == torch.float8_e4m3fn else 2
assert (out - out_ref).abs().max().item() <= mult * (
out_pt - out_ref
).abs().max().item() + 1e-5
mult_mean = 3 if dtype == torch.float8_e4m3fn else 1.5
assert (out - out_ref).abs().mean().item() <= mult_mean * (
out_pt - out_ref
).abs().mean().item()
def _generate_block_kvcache(
seqlen_k, page_size, batch_size, nheads_k, d, dv, device, dtype, dtype_ref
):
num_blocks = math.ceil(seqlen_k / page_size) * batch_size * 3
k_cache_paged = (
torch.randn(num_blocks, page_size, nheads_k, d, device=device, dtype=dtype_ref)
.to(dtype)
.to(dtype_ref)
)
v_cache_paged = (
torch.randn(num_blocks, page_size, nheads_k, dv, device=device, dtype=dtype_ref)
.to(dtype)
.to(dtype_ref)
)
page_table = rearrange(
torch.randperm(num_blocks, dtype=torch.int32, device=device),
"(b nblocks) -> b nblocks",
b=batch_size,
)
k_cache = rearrange(
k_cache_paged[page_table.flatten()],
"(b nblocks) block_size ... -> b (nblocks block_size) ...",
b=batch_size,
)[:, :seqlen_k]
v_cache = rearrange(
v_cache_paged[page_table.flatten()],
"(b nblocks) block_size ... -> b (nblocks block_size) ...",
b=batch_size,
)[:, :seqlen_k]
return k_cache, v_cache, page_table, k_cache_paged, v_cache_paged, num_blocks
@pytest.mark.skipif(
not is_fa3_supported(),
reason="flash_attn at sgl-kernel is only supported on sm90 or sm80",
)
# @pytest.mark.parametrize("dtype", [torch.float16, torch.bfloat16, torch.float8_e4m3fn])
@pytest.mark.parametrize(
"dtype", [torch.bfloat16] + ([torch.float8_e4m3fn] if not DISABLE_FP8 else [])
)
# @pytest.mark.parametrize("dtype", [torch.bfloat16])
# @pytest.mark.parametrize("dtype", [torch.float8_e4m3fn])
@pytest.mark.parametrize("mha_type", ["mha", "mqa", "gqa"])
# @pytest.mark.parametrize("mha_type", ["mha"])
@pytest.mark.parametrize("has_sink", [False, True])
# @pytest.mark.parametrize("has_sink", [False])
# @pytest.mark.parametrize("has_qv", [False, True])
@pytest.mark.parametrize("has_qv", [False])
# @pytest.mark.parametrize("deterministic", [False, True])
@pytest.mark.parametrize("deterministic", [False])
@pytest.mark.parametrize("softcap", [0.0] + ([15.0] if not DISABLE_SOFTCAP else []))
# @pytest.mark.parametrize("softcap", [0.0])
@pytest.mark.parametrize("local", [False])
# @pytest.mark.parametrize("local", [False])
@pytest.mark.parametrize("causal", [False, True])
# @pytest.mark.parametrize("causal", [False])
@pytest.mark.parametrize("add_unused_qkv", [False, True])
# @pytest.mark.parametrize("add_unused_qkv", [True])
# @pytest.mark.parametrize("d", [32, 64, 96, 128, 160, 192, 224, 256])
# @pytest.mark.parametrize('d', [32, 40, 64, 80, 96, 128, 160, 192, 256])
# @pytest.mark.parametrize('d', [32, 64, 96, 128, 160, 192])
# @pytest.mark.parametrize('d', [56, 80])
# @pytest.mark.parametrize('d', [32, 40, 64, 80, 96, 128])
# @pytest.mark.parametrize("d", [64, 96, 128])
# @pytest.mark.parametrize("d", COMPILED_HDIMS)
@pytest.mark.parametrize("d", [128])
@pytest.mark.parametrize(
"seqlen_q,seqlen_k",
[
(1, 1),
(1, 3),
(2, 1),
(511, 1),
(3, 513),
(64, 128),
(128, 128),
(256, 256),
(113, 203),
(128, 217),
(113, 211),
(108, 256),
(256, 512),
(307, 256),
(640, 128),
(512, 256),
(1024, 1024),
(1023, 1024),
(1024, 1023),
(2048, 2048),
],
)
def test_flash_attn_varlen_output(
seqlen_q,
seqlen_k,
d,
add_unused_qkv,
causal,
local,
softcap,
deterministic,
has_qv,
mha_type,
dtype,
has_sink,
):
from sgl_kernel.flash_attn import flash_attn_varlen_func
device = "cuda"
# set seed
torch.random.manual_seed(seqlen_q + seqlen_k + d + int(causal) * 2 + int(local))
# batch_size = 40
# nheads = 16
batch_size = 9 if seqlen_q <= 2048 else 2
nheads = 6
# batch_size = 2
# nheads = 1
nheads_kv = nheads if mha_type == "mha" else (2 if mha_type == "gqa" else 1)
dtype_ref = torch.bfloat16 if dtype == torch.float8_e4m3fn else dtype
dv_vals = [128, d] if d > 128 and d <= 192 else ([256, 512, d] if d <= 64 else [d])
if dtype == torch.float8_e4m3fn:
dv_vals = [d]
for dv in dv_vals:
q_ref = torch.randn(
batch_size, seqlen_q, nheads, d, device=device, dtype=dtype_ref
)
if softcap > 0.0:
# Ensure the values of qk are at least within softcap range.
q_ref = (q_ref * softcap / 4).detach().requires_grad_()
q_ref = q_ref.to(dtype).to(dtype_ref).requires_grad_()
k_ref = (
torch.randn(
batch_size, seqlen_k, nheads_kv, d, device=device, dtype=dtype_ref
)
.to(dtype)
.to(dtype_ref)
.requires_grad_()
)
v_ref = (
torch.randn(
batch_size, seqlen_k, nheads_kv, dv, device=device, dtype=dtype_ref
)
.to(dtype)
.to(dtype_ref)
.requires_grad_()
)
if has_qv:
qv_ref = (
torch.randn(
batch_size, seqlen_q, nheads, dv, device=device, dtype=dtype_ref
)
.to(dtype)
.to(dtype_ref)
)
else:
qv_ref = None
# Put window_size after QKV randn so that window_size changes from test to test
window_size = (-1, -1) if not local else torch.randint(0, seqlen_k, (2,))
if has_sink:
sinks = torch.randn(nheads, dtype=torch.bfloat16, device=device)
else:
sinks = None
if dtype == torch.float8_e4m3fn:
q_descale, k_descale, v_descale = [
torch.rand(batch_size, nheads_kv, device=device, dtype=torch.float32)
* 2
for _ in range(3)
]
else:
q_descale, k_descale, v_descale = None, None, None
q, k, v = [x.detach().requires_grad_() for x in (q_ref, k_ref, v_ref)]
qv = qv_ref.detach() if has_qv else None
query_padding_mask = generate_random_padding_mask(
seqlen_q, batch_size, device, mode="random", zero_lengths=False
)
key_padding_mask = generate_random_padding_mask(
seqlen_k, batch_size, device, mode="random", zero_lengths=True
)
def _gen_unused_masks(padding_mask, add_unused, max_seq_len, bs, device):
if add_unused:
another_mask = generate_random_padding_mask(max_seq_len, bs, device)
attn_mask = torch.logical_and(padding_mask, another_mask)
unused_mask = torch.logical_xor(
torch.logical_or(padding_mask, another_mask), attn_mask
)
else:
attn_mask = padding_mask
unused_mask = None
return attn_mask, unused_mask
query_padding_mask, query_unused_mask = _gen_unused_masks(
query_padding_mask, add_unused_qkv, seqlen_q, batch_size, q.device
)
key_padding_mask, key_unused_mask = _gen_unused_masks(
key_padding_mask, add_unused_qkv, seqlen_k, batch_size, k.device
)
(
q_unpad,
k_unpad,
v_unpad,
cu_seqlens_q,
cu_seqlens_k,
seqused_q,
seqused_k,
max_seqlen_q,
max_seqlen_k,
q,
k,
v,
output_pad_fn,
dq_pad_fn,
dk_pad_fn,
) = generate_qkv(
q,
k,
v,
query_padding_mask,
key_padding_mask,
kvpacked=False,
query_unused_mask=query_unused_mask,
key_unused_mask=key_unused_mask,
)
q_unpad, k_unpad, v_unpad = [
x.detach().to(dtype).requires_grad_() for x in (q_unpad, k_unpad, v_unpad)
]
out_ref, attn_ref = attention_ref(
q_ref,
k_ref,
v_ref,
query_padding_mask,
key_padding_mask,
causal=causal,
qv=qv_ref,
q_descale=q_descale,
k_descale=k_descale,
v_descale=v_descale,
window_size=window_size,
softcap=softcap,
sinks=sinks,
)
out_pt, attn_pt = attention_ref(
q_ref,
k_ref,
v_ref,
query_padding_mask,
key_padding_mask,
causal=causal,
qv=qv_ref,
q_descale=q_descale,
k_descale=k_descale,
v_descale=v_descale,
window_size=window_size,
softcap=softcap,
upcast=False,
reorder_ops=True,
intermediate_dtype=dtype if dtype == torch.float8_e4m3fn else None,
sinks=sinks,
)
print(f"Pytorch max diff: {(out_pt - out_ref).abs().max().item()}")
print(f"Pytorch mean diff: {(out_pt - out_ref).abs().mean().item()}")
if query_unused_mask is not None:
q_zero_masking = rearrange(query_unused_mask, "b s -> b s 1 1")
# Numerical error if we just do any arithmetic on out_ref
fwd_atol = 2 * (out_ref + 0.3 - 0.3 - out_ref).abs().max().item()
rtol = 2 if softcap == 0.0 else 3
pack_gqa_vals = [False, True] if not DISABLE_PACKGQA else [False]
num_splits_vals = [1, 3] if not DISABLE_SPLIT else [1]
for pack_gqa, num_splits in itertools.product(pack_gqa_vals, num_splits_vals):
out_unpad, lse, *rest = flash_attn_varlen_func(
q_unpad,
k_unpad,
v_unpad,
cu_seqlens_q,
cu_seqlens_k,
max_seqlen_q,
max_seqlen_k,
seqused_q=seqused_q,
seqused_k=seqused_k,
causal=causal,
q_descale=q_descale,
k_descale=k_descale,
v_descale=v_descale,
window_size=window_size,
softcap=softcap,
return_softmax_lse=True,
sinks=sinks,
)
out = output_pad_fn(out_unpad)
if query_unused_mask is not None:
out.masked_fill_(q_zero_masking, 0.0)
print(f"Output max diff: {(out - out_ref).abs().max().item()}")
print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
# Check that FlashAttention's numerical error is at most 3x the numerical error
# of a Pytorch implementation.
assert (out - out_ref).abs().max().item() <= rtol * (
out_pt - out_ref
).abs().max().item() + fwd_atol
if not DISABLE_BACKWARD and dtype != torch.float8_e4m3fn and not has_qv:
g_unpad = torch.randn_like(out_unpad)
do_o = ((g_unpad.float() * out_unpad.float()).sum(-1)).transpose(-1, -2)
dq_unpad, dk_unpad, dv_unpad = torch.autograd.grad(
out_unpad, (q_unpad, k_unpad, v_unpad), g_unpad
)
dq = dq_pad_fn(dq_unpad)
dk = dk_pad_fn(dk_unpad)
dv = dk_pad_fn(dv_unpad)
if key_unused_mask is not None:
k_zero_masking = rearrange(key_unused_mask, "b s -> b s 1 1")
dk.masked_fill_(k_zero_masking, 0.0)
dv.masked_fill_(k_zero_masking, 0.0)
if query_unused_mask is not None:
dq.masked_fill_(q_zero_masking, 0.0)
# print(f"dO_O max diff: {(softmax_d - do_o).abs().max().item()}")
# assert (softmax_d - do_o).abs().max().item() <= 1e-5
# assert dq_accum.abs().max().item() == 0.0
g = output_pad_fn(g_unpad)
# dq, dk, dv = torch.autograd.grad(out, (q, k, v), g)
dq_ref, dk_ref, dv_ref = torch.autograd.grad(out_ref, (q_ref, k_ref, v_ref), g)
dq_pt, dk_pt, dv_pt = torch.autograd.grad(out_pt, (q_ref, k_ref, v_ref), g)
print(f"dQ max diff: {(dq - dq_ref).abs().max().item()}")
print(f"dK max diff: {(dk - dk_ref).abs().max().item()}")
print(f"dV max diff: {(dv - dv_ref).abs().max().item()}")
print(f"dQ mean diff: {(dq - dq_ref).abs().mean().item()}")
print(f"dK mean diff: {(dk - dk_ref).abs().mean().item()}")
print(f"dV mean diff: {(dv - dv_ref).abs().mean().item()}")
print(f"dQ Pytorch max diff: {(dq_pt - dq_ref).abs().max().item()}")
print(f"dK Pytorch max diff: {(dk_pt - dk_ref).abs().max().item()}")
print(f"dV Pytorch max diff: {(dv_pt - dv_ref).abs().max().item()}")
print(f"dQ Pytorch mean diff: {(dq_pt - dq_ref).abs().mean().item()}")
print(f"dK Pytorch mean diff: {(dk_pt - dk_ref).abs().mean().item()}")
print(f"dV Pytorch mean diff: {(dv_pt - dv_ref).abs().mean().item()}")
if not DISABLE_BACKWARD and dtype != torch.float8_e4m3fn and not has_qv:
dq_atol = 2 * (dq_ref + 0.3 - 0.3 - dq_ref).abs().max().item() + (
0 if softcap == 0 else 3e-4
)
assert (dq - dq_ref).abs().max().item() <= rtol * (
dq_pt - dq_ref
).abs().max().item() + dq_atol
dk_atol = 2 * (dk_ref + 0.3 - 0.3 - dk_ref).abs().max().item() + (
0 if softcap == 0 else 3e-4
)
assert (dk - dk_ref).abs().max().item() <= rtol * (
dk_pt - dk_ref
).abs().max().item() + dk_atol
dv_atol = 2 * (dv_ref + 0.3 - 0.3 - dv_ref).abs().max().item() + (
0 if softcap == 0 else 3e-4
)
assert (dv - dv_ref).abs().max().item() <= rtol * (
dv_pt - dv_ref
).abs().max().item() + dv_atol
if __name__ == "__main__":
pytest.main([__file__])