Fixing non blocked attentions

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Nicolas Patry 2024-10-15 16:12:00 +02:00
parent 5e70158b2c
commit 4fa4da3cb6
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4 changed files with 265 additions and 165 deletions

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@ -5,68 +5,50 @@ import torch
from typing import Optional
if ATTENTION in {"flashinfer", "flashdecoding"}:
@dataclass
class Seqlen:
input_lengths: torch.Tensor
cache_lengths: torch.Tensor
cu_seqlen_q: Optional[torch.Tensor]
cu_seqlen_k: Optional[torch.Tensor]
max_q: int
max_k: int
@dataclass
class Seqlen:
input_lengths: torch.Tensor
cache_lengths: torch.Tensor
cu_seqlen_q: Optional[torch.Tensor]
cu_seqlen_k: Optional[torch.Tensor]
max_q: int
max_k: int
def __init__(
self,
input_lengths,
cache_lengths,
cu_seqlen_q=None,
max_q=None,
max_k=None,
):
self.input_lengths = input_lengths
self.cache_lengths = cache_lengths
device = self.input_lengths.device
shape = self.input_lengths.shape
if cu_seqlen_q is None:
cu_seqlen_q = torch.arange(
shape[0] + 1,
device=device,
dtype=torch.int32,
)
max_q = 1
else:
assert max_q is not None
assert max_k is not None
cu_seqlen_k = torch.zeros(shape[-1] + 1, device=device, dtype=torch.int32)
def __init__(
self,
input_lengths,
cache_lengths,
cu_seqlen_q=None,
max_q=None,
max_k=None,
):
self.input_lengths = input_lengths
self.cache_lengths = cache_lengths
device = self.input_lengths.device
shape = self.input_lengths.shape
if cu_seqlen_q is None:
cu_seqlen_q = torch.arange(
shape[0] + 1,
device=device,
dtype=torch.int32,
)
max_q = 1
else:
assert max_q is not None
assert max_k is not None
cu_seqlen_k = torch.zeros(shape[-1] + 1, device=device, dtype=torch.int32)
# cuda graphs don't like this and this is necessary to clamp within mistral
# Although FA2 might not want the clamping
# cu_seqlen_k[0] = 0
total = self.input_lengths + self.cache_lengths
torch.cumsum(total, -1, out=cu_seqlen_k[1:])
# cuda graphs don't like this and this is necessary to clamp within mistral
# Although FA2 might not want the clamping
# cu_seqlen_k[0] = 0
total = self.input_lengths + self.cache_lengths
torch.cumsum(total, -1, out=cu_seqlen_k[1:])
self.cu_seqlen_q = cu_seqlen_q
self.cu_seqlen_k = cu_seqlen_k
self.max_q = max_q
self.max_k = max_k
self.cu_seqlen_q = cu_seqlen_q
self.cu_seqlen_k = cu_seqlen_k
self.max_q = max_q
self.max_k = max_k
def clamp(self, max):
# Flash decoding doesn't need to clamp
return self
else:
@dataclass
class Seqlen:
input_lengths: torch.Tensor
cache_lengths: torch.Tensor
cu_seqlen_q: torch.Tensor
max_q: int
max_k: int
def clamp(self, max):
if SYSTEM == "rocm":
return self
raise NotImplementedError("Not implemented seqlen for paged")
return Seqlen(torch.clamp(self.input_lengths, max=max))
def clamp(self, max):
# Flash decoding doesn't need to clamp
return self

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@ -123,7 +123,7 @@ def paged_attention(
else:
if softcap is not None:
raise RuntimeError("Paged attention doesn't support softcapping")
input_lengths = seqlen.input_lengths
input_lengths = seqlen.input_lengths + seqlen.cache_lengths
from vllm._C import ops
out = torch.empty_like(query)
@ -243,118 +243,230 @@ if ATTENTION == "flashinfer":
sm_scale=softmax_scale,
window_left=window_size_left,
)
elif ATTENTION == "flashdecoding":
if V2:
elif V2:
def attention(
q,
key_cache: torch.Tensor,
value_cache: torch.Tensor,
seqlen: Seqlen,
block_tables: torch.Tensor,
softmax_scale,
window_size_left=-1,
causal=True,
softcap=0.0,
):
out = torch.empty_like(q)
if window_size_left <= 0 and window_size_left != -1:
raise ValueError("`window_size_left` must be > 0 or -1")
return flash_attn_2_cuda.varlen_fwd(
def attention(
q,
key_cache,
value_cache,
out,
seqlen.cu_seqlen_q,
seqlen.cu_seqlen_k,
None,
None,
block_tables,
None,
seqlen.max_q,
seqlen.max_k,
0.0,
key_cache: torch.Tensor,
value_cache: torch.Tensor,
seqlen: Seqlen,
block_tables: torch.Tensor,
softmax_scale,
False,
causal,
window_size_left,
0,
softcap,
False,
None,
)[0]
window_size_left=-1,
causal=True,
softcap=0.0,
):
out = torch.empty_like(q)
if window_size_left <= 0 and window_size_left != -1:
raise ValueError("`window_size_left` must be > 0 or -1")
return flash_attn_2_cuda.varlen_fwd(
q,
key_cache,
value_cache,
out,
seqlen.cu_seqlen_q,
seqlen.cu_seqlen_k,
None,
None,
block_tables,
None,
seqlen.max_q,
seqlen.max_k,
0.0,
softmax_scale,
False,
causal,
window_size_left,
0,
softcap,
False,
None,
)[0]
else:
else:
def attention(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
seqlen: Seqlen,
block_tables: torch.Tensor,
softmax_scale: float,
window_size_left: int = -1,
causal: bool = True,
softcap=None,
):
if window_size_left != -1:
raise NotImplementedError(
"window_size_left is only available with flash attn v2"
def attention(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
seqlen: Seqlen,
block_tables: torch.Tensor,
softmax_scale: float,
window_size_left: int = -1,
causal: bool = True,
softcap=None,
):
if window_size_left != -1:
raise NotImplementedError(
"window_size_left is only available with flash attn v2"
)
if softcap is not None:
raise NotImplementedError(
"softcap is only available with flash attn v2"
)
# Flash attention v1 requires q, k and v to have the same number of heads
if k.shape[1] != q.shape[1]:
# MQA expand
if k.shape[1] == 1:
k = k.expand(-1, q.shape[1], -1)
# Grouped attention reshape
else:
original_shape = k.shape
k = (
k.unsqueeze(2)
.expand(-1, -1, q.shape[1] // k.shape[1], -1)
.reshape(original_shape[0], -1, original_shape[2])
)
if v.shape[1] != q.shape[1]:
# MQA expand
if v.shape[1] == 1:
v = v.expand(-1, q.shape[1], -1)
# Grouped attention reshape
else:
original_shape = v.shape
v = (
v.unsqueeze(2)
.expand(-1, -1, q.shape[1] // v.shape[1], -1)
.reshape(original_shape[0], -1, original_shape[2])
)
out = torch.empty_like(q)
flash_attn_cuda.fwd(
q,
k,
v,
out,
seqlen.cu_seqlen_q,
seqlen.cu_seqlen_q,
seqlen.max_q,
seqlen.max_k,
0.0,
softmax_scale,
False,
causal,
False,
0,
None,
)
if softcap is not None:
raise NotImplementedError("softcap is only available with flash attn v2")
return out
elif ATTENTION == "paged":
if V2:
# Flash attention v1 requires q, k and v to have the same number of heads
if k.shape[1] != q.shape[1]:
# MQA expand
if k.shape[1] == 1:
k = k.expand(-1, q.shape[1], -1)
# Grouped attention reshape
else:
original_shape = k.shape
k = (
k.unsqueeze(2)
.expand(-1, -1, q.shape[1] // k.shape[1], -1)
.reshape(original_shape[0], -1, original_shape[2])
)
if v.shape[1] != q.shape[1]:
# MQA expand
if v.shape[1] == 1:
v = v.expand(-1, q.shape[1], -1)
# Grouped attention reshape
else:
original_shape = v.shape
v = (
v.unsqueeze(2)
.expand(-1, -1, q.shape[1] // v.shape[1], -1)
.reshape(original_shape[0], -1, original_shape[2])
)
out = torch.empty_like(q)
flash_attn_cuda.fwd(
def attention(
q,
k,
v,
out,
seqlen.cu_seqlen_q,
seqlen.cu_seqlen_q,
seqlen.max_q,
seqlen.max_k,
0.0,
key_cache: torch.Tensor,
value_cache: torch.Tensor,
seqlen: Seqlen,
block_tables: torch.Tensor,
softmax_scale,
False,
causal,
False,
0,
None,
)
return out
window_size_left=-1,
causal=True,
softcap=0.0,
):
out = torch.empty_like(q)
if window_size_left <= 0 and window_size_left != -1:
raise ValueError("`window_size_left` must be > 0 or -1")
return flash_attn_2_cuda.varlen_fwd(
q,
key_cache,
value_cache,
out,
seqlen.cu_seqlen_q,
seqlen.cu_seqlen_k,
None,
None,
None, # block_tables,
None,
seqlen.max_q,
seqlen.max_k,
0.0,
softmax_scale,
False,
causal,
window_size_left,
0,
softcap,
False,
None,
)[0]
else:
def attention(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
seqlen: Seqlen,
block_tables: torch.Tensor,
softmax_scale: float,
window_size_left: int = -1,
causal: bool = True,
softcap=None,
):
if window_size_left != -1:
raise NotImplementedError(
"window_size_left is only available with flash attn v2"
)
if softcap is not None:
raise NotImplementedError(
"softcap is only available with flash attn v2"
)
# Flash attention v1 requires q, k and v to have the same number of heads
if k.shape[1] != q.shape[1]:
# MQA expand
if k.shape[1] == 1:
k = k.expand(-1, q.shape[1], -1)
# Grouped attention reshape
else:
original_shape = k.shape
k = (
k.unsqueeze(2)
.expand(-1, -1, q.shape[1] // k.shape[1], -1)
.reshape(original_shape[0], -1, original_shape[2])
)
if v.shape[1] != q.shape[1]:
# MQA expand
if v.shape[1] == 1:
v = v.expand(-1, q.shape[1], -1)
# Grouped attention reshape
else:
original_shape = v.shape
v = (
v.unsqueeze(2)
.expand(-1, -1, q.shape[1] // v.shape[1], -1)
.reshape(original_shape[0], -1, original_shape[2])
)
out = torch.empty_like(q)
flash_attn_cuda.fwd(
q,
k,
v,
out,
seqlen.cu_seqlen_q,
seqlen.cu_seqlen_q,
seqlen.max_q,
seqlen.max_k,
0.0,
softmax_scale,
False,
causal,
False,
0,
None,
)
return out
else:
raise RuntimeError(f"Unknwon attention {ATTENTION}")
# Prefill in the cache with every kind of attention, unless we
# have a configuration that requires flash-attention v1, which
# does not support block tables.
PREFILL_IN_KV_CACHE = ATTENTION != "paged" or V2
PREFILL_IN_KV_CACHE = ATTENTION == "flashinfer" or (ATTENTION == "flashdecoding" and V2)
__all__ = [
"PREFILL_IN_KV_CACHE",

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@ -1602,6 +1602,8 @@ class FlashCausalLM(Model):
max_s = batch.max_current_length
lm_head_indices = batch.prefill_head_indices
print(slots)
if cu_seqlen_prefill is None and self.max_past() is not None:
# In decode, not prefill, we're actually overwriting the KV-cache
# in a circular buffer mode.
@ -1677,9 +1679,9 @@ class FlashCausalLM(Model):
cuda_graph["input_lengths"].zero_()
cuda_graph["input_lengths"][: input_lengths.shape[0]] = input_lengths
cuda_graph["cache_lengths"].zero_()
cuda_graph["cache_lengths"][
: cache_lengths_tensor.shape[0]
] = cache_lengths_tensor
cuda_graph["cache_lengths"][: cache_lengths_tensor.shape[0]] = (
cache_lengths_tensor
)
with self._forward_context(
block_tables=cuda_graph["block_tables"],

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@ -5,9 +5,13 @@ from typing import Dict, Optional
from text_generation_server.utils.log import log_master
PREFIX_CACHING = os.getenv("USE_PREFIX_CACHING", "1").lower() in {"1", "true"}
log_master(logger.info, f"Using prefix caching = {PREFIX_CACHING}")
ATTENTION = os.getenv("ATTENTION", "flashinfer")
default_prefix_caching = "1" if ATTENTION in {"flashinfer", "flashdecoding"} else "0"
PREFIX_CACHING = os.getenv("PREFIX_CACHING", default_prefix_caching).lower() in {
"1",
"true",
}
log_master(logger.info, f"Using prefix caching = {PREFIX_CACHING}")
_expected = {"paged", "flashdecoding", "flashinfer"}
assert (
ATTENTION in _expected