Files
xc-llm-ascend/vllm_ascend/attention/attention_cp.py
weijinqian0 35ad11b637 [Refactor] remove some metadata variables in attention_v1. (#5160)
RFC: https://github.com/vllm-project/vllm-ascend/issues/4629

Reason:

The metadata data class contains an excessive number of variables. We
will inherit the metadata of the community and simultaneously remove
some variables that are no longer needed at present.

Todo:
1. remove attn_state partly.

- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: weijinqian_v1 <weijinqian@huawei.com>
Co-authored-by: weijinqian_v1 <weijinqian@huawei.com>
2025-12-19 14:57:09 +08:00

914 lines
43 KiB
Python

#
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# This file is a part of the vllm-ascend project.
#
from typing import ClassVar, List, Optional, Tuple
import numpy as np
import torch
import torch.distributed as dist
import torch.nn as nn
import torch_npu
from vllm.config import VllmConfig
from vllm.distributed import (get_dcp_group,
get_decode_context_model_parallel_rank,
get_decode_context_model_parallel_world_size,
get_pcp_group)
from vllm.forward_context import ForwardContext, get_forward_context
from vllm.v1.attention.backends.utils import AttentionCGSupport
from vllm.v1.kv_cache_interface import AttentionSpec
from vllm_ascend.attention.attention_v1 import (AscendAttentionBackendImpl,
AscendAttentionMetadataBuilder,
AscendMetadata,
AscendMetadataForDecode,
AscendMetadataForPrefill)
from vllm_ascend.attention.utils import (AscendCommonAttentionMetadata,
filter_chunked_req_indices,
split_decodes_and_prefills)
from vllm_ascend.compilation.acl_graph import (get_graph_params,
update_graph_params_workspaces)
from vllm_ascend.utils import weak_ref_tensors
class AscendAttentionCPMetadataBuilder(AscendAttentionMetadataBuilder):
# Does this backend/builder support ACL Graphs for attention (default: no).
aclgraph_support: ClassVar[AttentionCGSupport] = \
AttentionCGSupport.ALWAYS
# AttentionCGSupport.UNIFORM_SINGLE_TOKEN_DECODE
# Does this backend/builder reorder the batch?
# If not, set this to None. Otherwise set it to the query
# length that will be pulled into the front of the batch.
reorder_batch_threshold: ClassVar[int] = 1
def __init__(
self,
kv_cache_spec: AttentionSpec,
layer_names: list[str],
vllm_config: VllmConfig,
device: torch.device,
):
super().__init__(kv_cache_spec, layer_names, vllm_config, device)
self.batch_seq_mask_buf = torch.empty(
vllm_config.scheduler_config.max_num_batched_tokens,
dtype=torch.uint8,
device=device)
self.pcp_size = get_pcp_group().world_size
self.pcp_rank = get_pcp_group(
).rank_in_group if self.pcp_size > 1 else 0
self.dcp_size = get_decode_context_model_parallel_world_size()
self.dcp_rank = get_decode_context_model_parallel_rank(
) if self.dcp_size > 1 else 0
def _get_chunked_req_mask(self, local_context_lens_allranks) -> List[bool]:
"""
given 4-d list [req][pcp][dcp], return:
1. if each req has any chunk (list[bool])
"""
assert local_context_lens_allranks is not None
if len(local_context_lens_allranks) == 0:
return []
chunked_req_mask = [(req.sum() > 0).item()
for req in local_context_lens_allranks
if req is not None]
return chunked_req_mask
def build(
self,
common_prefix_len: int,
common_attn_metadata: AscendCommonAttentionMetadata,
model: Optional[nn.Module] = None,
):
num_reqs = common_attn_metadata.num_reqs
num_actual_tokens = common_attn_metadata.num_actual_tokens
query_start_loc_cpu = common_attn_metadata.query_start_loc_cpu[:
num_reqs
+ 1]
num_decodes, num_prefills, num_decode_tokens, num_prefill_tokens = \
split_decodes_and_prefills(common_attn_metadata, decode_threshold=self.decode_threshold)
assert num_decodes + num_prefills == num_reqs
assert num_decode_tokens + num_prefill_tokens == num_actual_tokens
block_table = common_attn_metadata.block_table_tensor
query_lens = query_start_loc_cpu[1:] - query_start_loc_cpu[:-1]
seq_lens = common_attn_metadata.seq_lens_cpu[:num_reqs]
long_seq_metadata = common_attn_metadata.prefill_context_parallel_metadata
num_actual_tokens_pcp_padded = long_seq_metadata.num_actual_tokens_pcp_padded if long_seq_metadata else None
if num_actual_tokens_pcp_padded is None:
num_actual_tokens_pcp_padded = num_actual_tokens
slot_mapping = common_attn_metadata.slot_mapping[:
num_actual_tokens_pcp_padded]
attn_mask = common_attn_metadata.attn_mask
attn_state = common_attn_metadata.attn_state
num_computed_tokens_cpu = (seq_lens - query_lens)
query_start_loc = query_start_loc_cpu.to(self.device,
non_blocking=True)
common_long_seq_metadata = common_attn_metadata.prefill_context_parallel_metadata
prefill_metadata = None
decode_metadata = None
if common_long_seq_metadata is None:
raise AssertionError(
"common_long_seq_metadata should not be None.")
num_computed_tokens_of_pcp_dcp = common_long_seq_metadata.num_computed_tokens_of_pcp_dcp
assert num_computed_tokens_of_pcp_dcp is not None
chunked_context_metadata = None
if num_prefills > 0:
query_lens = query_lens[num_decode_tokens:]
context_lens_cpu = num_computed_tokens_cpu[num_decodes:num_reqs]
max_context_len_cpu = context_lens_cpu.max().item()
pcp_size = get_pcp_group().world_size
if self.chunked_prefill_enabled and max_context_len_cpu > 0:
local_context_lens_allranks = torch.tensor(
num_computed_tokens_of_pcp_dcp)[num_decodes:num_reqs].to(
self.device).to(dtype=torch.int32)
local_chunked_kv_lens_rank = local_context_lens_allranks[:,
self.
pcp_rank,
self.
dcp_rank]
actual_seq_lengths_kv = torch.cumsum(
local_chunked_kv_lens_rank, dim=0).tolist()
chunked_req_mask = self._get_chunked_req_mask(
local_context_lens_allranks)
local_chunk_starts = torch.zeros(
(len(local_context_lens_allranks)),
dtype=torch.int32,
device=self.device)
cp_kv_recover_idx_for_chunk = common_long_seq_metadata.cp_kv_recover_idx_for_chunk
kv_inverse_idx_for_chunk = torch.argsort(
cp_kv_recover_idx_for_chunk.to(torch.float32)
) if cp_kv_recover_idx_for_chunk is not None else None
batch_chunk_seq_mask = (
local_context_lens_allranks[:, self.pcp_rank,
self.dcp_rank] == 0)
batch_chunk_seq_mask = torch.repeat_interleave(
batch_chunk_seq_mask,
repeats=(query_lens * self.pcp_size).to(self.device))
chunk_seq_mask_filtered_indices = filter_chunked_req_indices(
query_lens, chunked_req_mask).to(self.device)
chunked_context_metadata = \
AscendMetadataForPrefill.ChunkedContextMetadata(
actual_chunk_seq_lengths=torch.cumsum(query_lens * pcp_size, dim=0),
actual_seq_lengths_kv=actual_seq_lengths_kv,
chunked_req_mask=chunked_req_mask,
starts=local_chunk_starts,
local_context_lens_allranks=local_context_lens_allranks,
cp_kv_recover_idx_for_chunk=cp_kv_recover_idx_for_chunk,
kv_inverse_idx_for_chunk=kv_inverse_idx_for_chunk,
batch_chunk_seq_mask=batch_chunk_seq_mask,
chunk_seq_mask_filtered_indices=chunk_seq_mask_filtered_indices
)
attn_mask_seqlens = common_long_seq_metadata.attn_mask_seqlens
head_attn_nomask_seqlens = common_long_seq_metadata.head_attn_nomask_seqlens
tail_attn_nomask_seqlens = common_long_seq_metadata.tail_attn_nomask_seqlens
if pcp_size > 1:
attn_mask_seqlens = torch.cumsum(attn_mask_seqlens[0],
dim=0).tolist()
head_attn_nomask_seqlens = torch.cumsum(
head_attn_nomask_seqlens[1], dim=0).tolist()
tail_attn_nomask_seqlens = torch.cumsum(
tail_attn_nomask_seqlens[1], dim=0).tolist()
pcp_metadata = AscendMetadataForPrefill.AscendPCPMetadata(
q_head_idx=common_long_seq_metadata.q_head_idx_tensor,
q_tail_idx=common_long_seq_metadata.q_tail_idx_tensor,
kv_with_q_head_nomask_idx=common_long_seq_metadata.
kv_with_q_head_nomask_idx_tensor,
kv_with_q_head_mask_idx=common_long_seq_metadata.
kv_with_q_head_mask_idx_tensor,
kv_with_q_tail_nomask_idx=common_long_seq_metadata.
kv_with_q_tail_nomask_idx_tensor,
kv_with_q_tail_mask_idx=common_long_seq_metadata.
kv_with_q_tail_mask_idx_tensor,
attn_mask_seqlens=attn_mask_seqlens,
head_attn_nomask_seqlens=head_attn_nomask_seqlens,
tail_attn_nomask_seqlens=tail_attn_nomask_seqlens,
q_full_idx=common_long_seq_metadata.q_full_idx,
pcp_prefill_mask=common_long_seq_metadata.pcp_prefill_mask)
prefill_metadata = AscendMetadataForPrefill(
pcp_metadata=pcp_metadata,
pcp_allgather_restore_idx=common_long_seq_metadata.
pcp_allgather_restore_idx
if common_long_seq_metadata is not None else None,
chunked_context=chunked_context_metadata,
block_tables=block_table[num_decodes:],
actual_seq_lengths_q=torch.cumsum(query_lens, dim=0))
if num_decodes > 0:
num_computed_tokens_array = np.array(
num_computed_tokens_of_pcp_dcp)
num_computed_tokens_array = num_computed_tokens_array[:num_decodes]
batch_seq_mask = (num_computed_tokens_array[:, self.pcp_rank,
self.dcp_rank] == 0)
# TODO: numpy array mode of the shared memory is used to improve performance
self.batch_seq_mask_buf[:batch_seq_mask.shape[0]].copy_(
torch.from_numpy(batch_seq_mask), non_blocking=True)
decode_metadata = AscendMetadataForDecode(
num_computed_tokens_of_pcp_dcp=num_computed_tokens_array,
batch_seq_mask=self.batch_seq_mask_buf[:batch_seq_mask.
shape[0]],
block_tables=block_table[:num_decodes])
attn_metadata = AscendMetadata(
num_actual_tokens=num_actual_tokens,
num_decode_tokens=num_decode_tokens,
num_actual_tokens_pcp_padded=num_actual_tokens_pcp_padded,
block_tables=block_table,
query_start_loc=query_start_loc,
seq_lens=seq_lens,
seq_lens_list=seq_lens.tolist(),
max_query_len=common_attn_metadata.max_query_len,
actual_seq_lengths_q=query_start_loc_cpu[1:].tolist(),
slot_mapping=slot_mapping,
attn_mask=attn_mask,
attn_state=attn_state,
num_prefills=num_prefills,
num_decodes=num_decodes,
prefill=prefill_metadata,
decode_meta=decode_metadata)
return attn_metadata
class AscendAttentionCPImpl(AscendAttentionBackendImpl):
def __init__(
self,
num_heads: int,
head_size: int,
scale: float,
num_kv_heads: int,
alibi_slopes: Optional[List[float]],
sliding_window: Optional[int],
kv_cache_dtype: str,
logits_soft_cap: Optional[float],
attn_type: str,
kv_sharing_target_layer_name: Optional[str],
**kwargs,
) -> None:
super().__init__(num_heads, head_size, scale, num_kv_heads,
alibi_slopes, sliding_window, kv_cache_dtype,
logits_soft_cap, attn_type,
kv_sharing_target_layer_name, **kwargs)
self.pcp_size = get_pcp_group().world_size
self.pcp_rank = get_pcp_group(
).rank_in_group if self.pcp_size > 1 else 0
self.pcp_group = get_pcp_group(
).device_group if self.pcp_size > 1 else None
self.dcp_size = get_decode_context_model_parallel_world_size()
self.dcp_rank = get_decode_context_model_parallel_rank(
) if self.dcp_size > 1 else 0
self.dcp_group = get_dcp_group(
).device_group if self.dcp_size > 1 else None
def _attention_with_nomask_and_mask(self, q: torch.Tensor,
q_seqlens: List[int],
k_nomask: torch.Tensor,
v_nomask: torch.Tensor,
kv_seqlens_nomask: List[int],
k_mask: torch.Tensor,
v_mask: torch.Tensor,
kv_seqlens_mask: List[int],
mask: torch.Tensor,
attn_metadata) -> torch.Tensor:
# nomask Attention
if k_nomask is not None:
attn_out_nomask, attn_lse_nomask = torch.ops.npu.npu_fused_infer_attention_score(
q,
k_nomask,
v_nomask,
num_heads=self.num_heads,
num_key_value_heads=self.num_kv_heads,
input_layout="TND",
atten_mask=None,
scale=self.scale,
sparse_mode=0,
antiquant_mode=0,
antiquant_scale=None,
softmax_lse_flag=True,
actual_seq_lengths_kv=kv_seqlens_nomask,
actual_seq_lengths=q_seqlens)
# mask Attention
attn_out_mask, attn_lse_mask = torch.ops.npu.npu_fused_infer_attention_score(
q,
k_mask,
v_mask,
num_heads=self.num_heads,
num_key_value_heads=self.num_kv_heads,
input_layout="TND",
atten_mask=mask,
scale=self.scale,
sparse_mode=3,
antiquant_mode=0,
antiquant_scale=None,
softmax_lse_flag=True,
actual_seq_lengths_kv=kv_seqlens_mask,
actual_seq_lengths=q_seqlens)
# update
output = attn_out_mask
attn_lse = attn_lse_mask
if k_nomask is not None:
if attn_metadata.prefill is not None and attn_metadata.prefill.chunked_context is None:
output = self._npu_attn_out_lse_update(attn_lse_mask,
attn_lse_nomask,
attn_out_mask,
attn_out_nomask)
attn_lse = None
else:
output, attn_lse = self._update_out_and_lse(
torch.stack([attn_out_nomask, attn_out_mask], dim=0),
torch.stack([attn_lse_nomask, attn_lse_mask], dim=0))
return output, attn_lse
def _npu_attn_out_lse_update(self, attn_lse_mask, attn_lse_nomask,
attn_out_mask, attn_out_nomask):
T = attn_out_mask.shape[0]
N = attn_out_mask.shape[1]
D = attn_out_mask.shape[2]
attn_out_mask, attn_lse_mask = self._out_lse_reshape(
attn_out_mask, attn_lse_mask)
attn_out_nomask, attn_lse_nomask = self._out_lse_reshape(
attn_out_nomask, attn_lse_nomask)
attn_out_mask = attn_out_mask.to(torch.float32)
attn_out_nomask = attn_out_nomask.to(torch.float32)
attn_lse_mask = attn_lse_mask.to(torch.float32)
attn_lse_nomask = attn_lse_nomask.to(torch.float32)
attn_output = [attn_out_nomask, attn_out_mask]
attn_lse = [attn_lse_nomask, attn_lse_mask]
update_type = 0
output, _ = torch_npu.npu_attention_update(attn_lse, attn_output,
update_type)
output = output.view(T, N, D)
return output
def _forward_prefill_cp(self, query: torch.Tensor, key: torch.Tensor,
value: torch.Tensor,
attn_metadata: AscendMetadata) -> torch.Tensor:
assert attn_metadata is not None
assert attn_metadata.prefill is not None
assert attn_metadata.prefill.pcp_metadata is not None
# Use precomputed indices from the metadata (already converted to tensors and on device)
q_head_idx = attn_metadata.prefill.pcp_metadata.q_head_idx
q_tail_idx = attn_metadata.prefill.pcp_metadata.q_tail_idx
kv_with_q_head_nomask_idx = attn_metadata.prefill.pcp_metadata.kv_with_q_head_nomask_idx
kv_with_q_head_mask_idx = attn_metadata.prefill.pcp_metadata.kv_with_q_head_mask_idx
kv_with_q_tail_nomask_idx = attn_metadata.prefill.pcp_metadata.kv_with_q_tail_nomask_idx
kv_with_q_tail_mask_idx = attn_metadata.prefill.pcp_metadata.kv_with_q_tail_mask_idx
attn_mask_seqlens = attn_metadata.prefill.pcp_metadata.attn_mask_seqlens
head_attn_nomask_seqlens = attn_metadata.prefill.pcp_metadata.head_attn_nomask_seqlens
tail_attn_nomask_seqlens = attn_metadata.prefill.pcp_metadata.tail_attn_nomask_seqlens
mask = attn_metadata.prefill.pcp_metadata.pcp_prefill_mask
# 1. Attention calculation in the first half of Q in load balancing
output_heads, lse_heads = self._attention_with_nomask_and_mask(
q=torch.index_select(query, 0, q_head_idx),
q_seqlens=attn_mask_seqlens,
k_nomask=torch.index_select(key, 0, kv_with_q_head_nomask_idx)
if self.pcp_rank > 0 else None,
v_nomask=torch.index_select(value, 0, kv_with_q_head_nomask_idx)
if self.pcp_rank > 0 else None,
kv_seqlens_nomask=head_attn_nomask_seqlens,
k_mask=torch.index_select(key, 0, kv_with_q_head_mask_idx),
v_mask=torch.index_select(value, 0, kv_with_q_head_mask_idx),
kv_seqlens_mask=attn_mask_seqlens,
mask=mask,
attn_metadata=attn_metadata)
# 2. the Attention calculation in the latter half of Q in load balancing
# pcp_rank0: Q3*KV0~KV2 + Q3*KV3
# pcp_rank1: Q2*KV0~KV1 + Q2*KV2
output_tails, lse_tails = self._attention_with_nomask_and_mask(
q=torch.index_select(query, 0, q_tail_idx),
q_seqlens=attn_mask_seqlens,
k_nomask=torch.index_select(key, 0, kv_with_q_tail_nomask_idx),
v_nomask=torch.index_select(value, 0, kv_with_q_tail_nomask_idx),
kv_seqlens_nomask=tail_attn_nomask_seqlens,
k_mask=torch.index_select(key, 0, kv_with_q_tail_mask_idx),
v_mask=torch.index_select(value, 0, kv_with_q_tail_mask_idx),
kv_seqlens_mask=attn_mask_seqlens,
mask=mask,
attn_metadata=attn_metadata)
q_full_idx = attn_metadata.prefill.pcp_metadata.q_full_idx
output = torch.index_select(
torch.cat([output_heads, output_tails], dim=0), 0, q_full_idx)
attn_lse = None
if attn_metadata.prefill is not None and attn_metadata.prefill.chunked_context is not None:
attn_lse = torch.index_select(
torch.cat([lse_heads, lse_tails], dim=0), 0, q_full_idx)
return output, attn_lse
def _out_lse_reshape(self, attn_out: torch.Tensor,
attn_lse: torch.Tensor) -> torch.Tensor:
attn_out = attn_out.contiguous().view(
attn_out.shape[0] * attn_out.shape[1], attn_out.shape[2])
attn_lse = attn_lse.contiguous().view(
attn_lse.shape[0] * attn_lse.shape[1] * attn_lse.shape[2])
return attn_out, attn_lse
def _npu_attention_update(
self, attn_out_lse_list: List[torch.Tensor]) -> torch.Tensor:
update_type = 0
batch = attn_out_lse_list[0].shape[0]
num_heads = attn_out_lse_list[0].shape[1]
head_dim = attn_out_lse_list[0].shape[2] - 1
attn_out_split_cp = []
attn_lse_split_cp = []
for i in attn_out_lse_list:
attn_out_allgather, attn_lse_allgather = self._out_lse_reshape(
*torch.split(i, [self.head_size, 1], dim=-1))
attn_out_split_cp.append(attn_out_allgather)
attn_lse_split_cp.append(attn_lse_allgather)
attn_out, attn_lse = torch_npu.npu_attention_update(
attn_lse_split_cp, attn_out_split_cp, update_type)
attn_out = attn_out.view(batch, num_heads, head_dim)
return attn_out
def _forward_decode_pcp_dcp(self, query: torch.Tensor,
attn_metadata: AscendMetadata) -> torch.Tensor:
assert self.key_cache is not None
assert self.value_cache is not None
if self.dcp_size > 1:
query = get_dcp_group().all_gather(query, 1)
num_heads = self.num_heads * self.dcp_size
else:
num_heads = self.num_heads
k_nope = self.key_cache.view(self.key_cache.shape[0],
self.key_cache.shape[1], -1)
value = self.value_cache.view(self.key_cache.shape[0],
self.key_cache.shape[1], -1)
common_kwargs = {
'num_heads':
num_heads,
'num_key_value_heads':
self.num_kv_heads,
'input_layout':
'TND',
'atten_mask':
None,
'scale':
self.scale,
'antiquant_mode':
0,
'antiquant_scale':
None,
'softmax_lse_flag':
True,
'block_table':
attn_metadata.decode_meta.block_tables,
'block_size':
self.key_cache.shape[1],
'actual_seq_lengths_kv':
attn_metadata.decode_meta.
num_computed_tokens_of_pcp_dcp[:, self.pcp_rank, self.dcp_rank],
'actual_seq_lengths':
attn_metadata.actual_seq_lengths_q[:attn_metadata.num_decodes],
}
graph_params = get_graph_params()
forward_context: ForwardContext = get_forward_context()
num_tokens = query.shape[0]
if forward_context.capturing:
stream = torch_npu.npu.current_stream()
event = torch.npu.ExternalEvent()
event.wait(stream)
event.reset(stream)
graph_params.events[num_tokens].append(event)
workspace = graph_params.workspaces.get(num_tokens)
if workspace is None:
workspace = torch_npu._npu_fused_infer_attention_score_get_max_workspace(
query, k_nope, value, **common_kwargs)
update_graph_params_workspaces(num_tokens,
weak_ref_tensors(workspace))
attn_out = torch.empty_like(query)
attn_lse = torch.empty((num_tokens, num_heads, 1),
dtype=torch.float,
device=query.device)
graph_params.attn_params[num_tokens].append((
weak_ref_tensors(query), weak_ref_tensors(k_nope),
weak_ref_tensors(value), self.num_heads, self.num_kv_heads,
self.scale, attn_metadata.block_tables,
self.key_cache.shape[1], attn_metadata.decode_meta.
num_computed_tokens_of_pcp_dcp[:, self.pcp_rank,
self.dcp_rank],
attn_metadata.actual_seq_lengths_q[:attn_metadata.num_decodes],
weak_ref_tensors(attn_out), weak_ref_tensors(attn_lse),
self.dcp_size, self.pcp_rank, self.dcp_rank))
torch.npu.graph_task_group_begin(stream)
torch_npu.npu_fused_infer_attention_score.out(
query,
k_nope,
value,
**common_kwargs,
workspace=workspace,
out=[attn_out, attn_lse])
handle = torch.npu.graph_task_group_end(stream)
graph_params.handles[num_tokens].append(handle)
else:
attn_out, attn_lse = torch_npu.npu_fused_infer_attention_score(
query, k_nope, value, **common_kwargs)
out_mask = attn_metadata.decode_meta.batch_seq_mask[:, None,
None].expand_as(
attn_out)
attn_out = torch.where(out_mask, 0, attn_out)
lse_mask = attn_metadata.decode_meta.batch_seq_mask[:, None,
None].expand_as(
attn_lse)
attn_lse = torch.where(lse_mask, -torch.inf, attn_lse)
attn_out_lse_list = []
# Concat out&lse: [bs,num_heads,v_head_dim] + [bs,num_heads,1] -> [bs,num_heads,v_head_dim+1]
attn_out_lse = torch.cat([attn_out, attn_lse], dim=-1)
if self.dcp_size > 1:
# permute: [bs, num_heads, v_head_dim+1] -> [num_heads, v_head_dim+1, bs]
attn_out_lse = attn_out_lse.permute([1, 2, 0]).contiguous()
attn_out_lse_all2all = torch.empty_like(attn_out_lse)
dist.all_to_all_single(attn_out_lse_all2all,
attn_out_lse,
group=self.dcp_group)
# permute: [num_heads, v_head_dim+1, bs] -> [bs, num_heads, v_head_dim+1]
attn_out_lse_all2all = attn_out_lse_all2all.permute([2, 0, 1])
if self.pcp_size > 1:
attn_out_lse = attn_out_lse_all2all.contiguous()
attn_out_lse_list = list(
torch.chunk(attn_out_lse_all2all, self.dcp_size, dim=1))
if self.pcp_size > 1:
# AllGather out&lse within CP group
attn_out_lse_list = [
torch.empty_like(attn_out_lse) for _ in range(self.pcp_size)
]
dist.all_gather(attn_out_lse_list,
attn_out_lse,
group=self.pcp_group)
if self.dcp_size > 1 and self.pcp_size > 1:
attn_out_lse_list_pcp_dcp = []
for s in attn_out_lse_list:
attn_out_lse_list_split = list(
torch.chunk(s, self.dcp_size, dim=1))
attn_out_lse_list_pcp_dcp += attn_out_lse_list_split
attn_out_lse_list = attn_out_lse_list_pcp_dcp
# Update out&lse
attn_out = self._npu_attention_update(attn_out_lse_list)
return attn_out
def _update_out_and_lse(self, out_list: torch.Tensor,
lse_list: torch.Tensor) -> torch.Tensor:
"""LSE_final = log(sum(exp(LSE_i))), O_final = sum(exp(LSE_i - LSE_final) * O_i)
Args:
out_list: shape = [N, batch_size, num_heads, head_size]
lse_list: shape = [N, batch_size, num_heads, 1]
Returns:
out_final: shape = [batch_size, num_heads, head_size]
lse_final: shape = [batch_size, num_heads, 1]
"""
lse_final = torch.logsumexp(lse_list, dim=0, keepdim=False)
out_final = torch.sum(torch.exp(lse_list - lse_final) * out_list,
dim=0)
return out_final, lse_final
def _process_chunk_prefill(self, current_attn_output_prefill,
current_attn_lse_prefill, kv_cache,
prefill_query, attn_metadata):
if attn_metadata.prefill is not None and attn_metadata.prefill.chunked_context is not None:
prefill_query_all = self._prefill_query_all_gather(
attn_metadata, prefill_query)
attn_output_full_chunk, attn_lse_full_chunk = self._compute_prefill_context(
prefill_query_all, kv_cache, attn_metadata)
self._update_chunk_attn_out_lse_with_current_attn_out_lse(
current_attn_output_prefill, current_attn_lse_prefill,
attn_output_full_chunk, attn_lse_full_chunk, prefill_query,
attn_metadata)
def _update_chunk_attn_out_lse_with_current_attn_out_lse(
self, current_attn_output_prefill, current_attn_lse_prefill,
attn_output_full_chunk, attn_lse_full_chunk, prefill_query,
attn_metadata):
if self.pcp_size > 1:
inverse_idx = attn_metadata.prefill.chunked_context.kv_inverse_idx_for_chunk
attn_output_full_chunk = torch.index_select(
attn_output_full_chunk, 0, inverse_idx)
attn_lse_full_chunk = torch.index_select(attn_lse_full_chunk, 0,
inverse_idx)
num_tokens = prefill_query.size(0)
attn_output_full_chunk = attn_output_full_chunk[
self.pcp_rank * num_tokens:(self.pcp_rank + 1) * num_tokens, :, :]
attn_lse_full_chunk = attn_lse_full_chunk[
self.pcp_rank * num_tokens:(self.pcp_rank + 1) * num_tokens, :, :]
assert attn_output_full_chunk.shape == current_attn_output_prefill.shape and attn_lse_full_chunk.shape == current_attn_lse_prefill.shape
filtered_indices = attn_metadata.prefill.chunked_context.chunk_seq_mask_filtered_indices
attn_output_prefill_filtered = current_attn_output_prefill[
filtered_indices, :, :]
attn_lse_prefill_filtered = current_attn_lse_prefill[
filtered_indices, :, :]
attn_output_full_chunk = attn_output_full_chunk[filtered_indices, :, :]
attn_lse_full_chunk = attn_lse_full_chunk[filtered_indices, :, :]
attn_output_filtered = self._npu_attn_out_lse_update(
attn_lse_prefill_filtered, attn_lse_full_chunk,
attn_output_prefill_filtered, attn_output_full_chunk)
current_attn_output_prefill[
filtered_indices, :, :] = attn_output_filtered.to(
current_attn_output_prefill.dtype)
def _prefill_query_all_gather(self, attn_metadata, prefill_query):
if self.dcp_size > 1:
prefill_query = get_dcp_group().all_gather(prefill_query, 1)
if self.pcp_size > 1:
prefill_query = get_pcp_group().all_gather(prefill_query, 0)
prefill_query_all = torch.index_select(prefill_query,
0,
attn_metadata.prefill.chunked_context.cp_kv_recover_idx_for_chunk) \
if self.pcp_size > 1 else prefill_query
return prefill_query_all
def _compute_prefill_context(self, query: torch.Tensor,
kv_cache: Tuple[torch.Tensor],
attn_metadata: AscendMetadata):
assert len(kv_cache) > 1
assert attn_metadata is not None
assert attn_metadata.prefill is not None
assert attn_metadata.prefill.chunked_context is not None
prefill_metadata = attn_metadata.prefill
local_chunked_kv_lens = prefill_metadata.chunked_context.local_context_lens_allranks
assert local_chunked_kv_lens is not None
local_chunked_kv_lens_rank = local_chunked_kv_lens[:, self.pcp_rank,
self.dcp_rank]
total_toks = local_chunked_kv_lens_rank.sum()
key, value = self._load_kv_for_chunk(attn_metadata, kv_cache,
local_chunked_kv_lens_rank, query,
total_toks)
if self.dcp_size > 1:
num_heads = self.num_heads * self.dcp_size
else:
num_heads = self.num_heads
prefix_chunk_output = torch.full(
(query.size(0), num_heads, self.head_size),
fill_value=0,
dtype=query.dtype,
device=query.device)
prefix_chunk_lse = torch.full((query.size(0), num_heads, 1),
fill_value=-torch.inf,
dtype=torch.float32,
device=query.device)
if total_toks > 0:
prefix_chunk_output, prefix_chunk_lse = torch.ops.npu.npu_fused_infer_attention_score(
query,
key,
value,
num_heads=num_heads,
num_key_value_heads=self.num_kv_heads,
input_layout="TND",
atten_mask=None,
scale=self.scale,
sparse_mode=0,
antiquant_mode=0,
antiquant_scale=None,
softmax_lse_flag=True,
actual_seq_lengths_kv=prefill_metadata.chunked_context.
actual_seq_lengths_kv,
actual_seq_lengths=attn_metadata.prefill.chunked_context.
actual_chunk_seq_lengths)
batch_chunk_seq_mask = attn_metadata.prefill.chunked_context.batch_chunk_seq_mask
out_mask = batch_chunk_seq_mask[:, None, None].expand_as(
prefix_chunk_output)
prefix_chunk_output = torch.where(out_mask, 0, prefix_chunk_output)
lse_mask = batch_chunk_seq_mask[:, None,
None].expand_as(prefix_chunk_lse)
prefix_chunk_lse = torch.where(lse_mask, -torch.inf,
prefix_chunk_lse)
prefix_output, prefix_lse = self._update_chunk_attn_out_lse(
prefix_chunk_output, prefix_chunk_lse)
return prefix_output, prefix_lse
def _update_chunk_attn_out_lse(self, prefix_chunk_output,
prefix_chunk_lse):
# CP dimension all_gather and fusion
chunk_attn_out_lse = torch.cat([prefix_chunk_output, prefix_chunk_lse],
dim=-1)
if self.dcp_size > 1:
chunk_attn_out_lse = chunk_attn_out_lse.permute([1, 2,
0]).contiguous()
attn_out_lse_all2all = torch.empty_like(chunk_attn_out_lse)
dist.all_to_all_single(attn_out_lse_all2all,
chunk_attn_out_lse,
group=self.dcp_group)
attn_out_lse_all2all = attn_out_lse_all2all.permute([2, 0, 1])
if self.pcp_size > 1:
chunk_attn_out_lse = attn_out_lse_all2all.contiguous()
attn_out_lse_list = list(
torch.chunk(attn_out_lse_all2all, self.dcp_size, dim=1))
if self.pcp_size > 1:
attn_out_lse_list = [
torch.empty_like(chunk_attn_out_lse)
for _ in range(self.pcp_size)
]
dist.all_gather(attn_out_lse_list,
chunk_attn_out_lse,
group=self.pcp_group)
if self.dcp_size > 1 and self.pcp_size > 1:
attn_out_lse_list_pcp_dcp = []
for s in attn_out_lse_list:
attn_out_lse_list_split = list(
torch.chunk(s, self.dcp_size, dim=1))
attn_out_lse_list_pcp_dcp += attn_out_lse_list_split
attn_out_lse_list = attn_out_lse_list_pcp_dcp
attn_out_lse_allgather = torch.stack(
attn_out_lse_list,
dim=0) # [pcp, batch_size, num_heads, head_size+1]
attn_out_allgather, attn_lse_allgather = torch.split(
attn_out_lse_allgather, [self.head_size, 1], dim=-1)
prefix_output, prefix_lse = self._update_out_and_lse(
attn_out_allgather, attn_lse_allgather)
return prefix_output, prefix_lse
def _load_kv_for_chunk(self, attn_metadata, kv_cache,
local_chunked_kv_lens_rank, query, total_toks):
cache_key = kv_cache[0]
cache_value = kv_cache[1]
num_heads = cache_key.size(2)
head_size = kv_cache[0].size(-1)
key = torch.empty(total_toks,
num_heads,
head_size,
dtype=query.dtype,
device=query.device)
value = torch.empty(total_toks,
num_heads,
head_size,
dtype=query.dtype,
device=query.device)
if total_toks > 0:
torch_npu.atb.npu_paged_cache_load(
cache_key,
cache_value,
attn_metadata.prefill.block_tables,
local_chunked_kv_lens_rank,
seq_starts=attn_metadata.prefill.chunked_context.
starts, # slot offsets of current chunk in current iteration
key=key,
value=value,
)
return key, value
def reshape_and_cache(
self,
key: torch.Tensor,
value: torch.Tensor,
kv_cache: Tuple[torch.Tensor],
attn_metadata: AscendMetadata,
):
num_decode_tokens = attn_metadata.num_decode_tokens
has_decode = attn_metadata.num_decodes > 0
has_prefill = attn_metadata.num_prefills > 0
if len(kv_cache) > 1:
if self.key_cache is None:
self.key_cache, self.value_cache = kv_cache[0], kv_cache[1]
if has_decode:
slot_mapping = attn_metadata.slot_mapping[:num_decode_tokens *
self.pcp_size:self.
pcp_size]
torch_npu._npu_reshape_and_cache(
key=key[:num_decode_tokens],
value=value[:num_decode_tokens],
key_cache=self.key_cache,
value_cache=self.value_cache,
slot_indices=slot_mapping)
if has_prefill:
if self.pcp_size > 1:
kv = torch.cat([key, value], dim=-1)
num_actual_tokens_pcp_padded = attn_metadata.num_actual_tokens_pcp_padded // self.pcp_size
all_kv = get_pcp_group().all_gather(
kv[:num_actual_tokens_pcp_padded].contiguous(), dim=0)
pcp_allgather_restore_idx = attn_metadata.prefill.pcp_allgather_restore_idx if attn_metadata.prefill else None
all_kv = torch.index_select(all_kv, 0,
pcp_allgather_restore_idx)
key, value = all_kv.split([self.head_size, self.head_size],
dim=-1)
torch_npu._npu_reshape_and_cache(
key=key[self.pcp_size * num_decode_tokens:attn_metadata.
num_actual_tokens_pcp_padded],
value=value[self.pcp_size *
num_decode_tokens:attn_metadata.
num_actual_tokens_pcp_padded],
key_cache=self.key_cache,
value_cache=self.value_cache,
slot_indices=attn_metadata.
slot_mapping[self.pcp_size *
num_decode_tokens:attn_metadata.
num_actual_tokens_pcp_padded])
return key, value
def forward_impl(
self,
query: torch.Tensor,
key: torch.Tensor,
value: torch.Tensor,
kv_cache: Tuple[torch.Tensor],
attn_metadata: AscendMetadata,
output: torch.Tensor,
) -> torch.Tensor:
assert attn_metadata is not None
has_decode = attn_metadata.num_decodes > 0
has_prefill = attn_metadata.num_prefills > 0
num_decode_tokens = attn_metadata.num_decode_tokens
if has_decode:
decode_query = query[:num_decode_tokens]
output_decode = self._forward_decode_pcp_dcp(
decode_query, attn_metadata)
output[:num_decode_tokens] = output_decode
if has_prefill:
assert attn_metadata.prefill is not None
num_actual_tokens_pcp_padded = attn_metadata.num_actual_tokens_pcp_padded // self.pcp_size
prefill_query = query[
num_decode_tokens:num_actual_tokens_pcp_padded]
key = key[self.pcp_size * num_decode_tokens:]
value = value[self.pcp_size * num_decode_tokens:]
if self.pcp_size > 1:
# Scenario of Enabling PCP or PCP&DCP
attn_output_prefill, attn_lse_prefill = self._forward_prefill_cp(
prefill_query, key, value, attn_metadata)
else:
# Scenario of Enabling DCP Individually
attn_output_prefill, attn_lse_prefill = torch.ops.npu.npu_fused_infer_attention_score(
prefill_query,
key,
value,
num_heads=self.num_heads,
num_key_value_heads=self.num_kv_heads,
input_layout="TND",
atten_mask=attn_metadata.attn_mask,
scale=self.scale,
sparse_mode=3,
antiquant_mode=0,
antiquant_scale=None,
softmax_lse_flag=True,
actual_seq_lengths_kv=attn_metadata.prefill.
actual_seq_lengths_q,
actual_seq_lengths=attn_metadata.prefill.
actual_seq_lengths_q)
self._process_chunk_prefill(attn_output_prefill, attn_lse_prefill,
kv_cache, prefill_query, attn_metadata)
output[num_decode_tokens:attn_output_prefill.shape[0] +
num_decode_tokens] = attn_output_prefill
return output