Files
xc-llm-ascend/vllm_ascend/distributed/parallel_state.py
wangxiaoteng888 ca05f7d632 [Bugfix] TP size larger than KV cache head causes accuracy issues (#3366)
### What this PR does / why we need it?
Resolve the issue where, in the case of unequal TP (Tensor Parallelism),
the TP size is larger than the number of model attention kvcache heads,
causing the KV cache to generate duplicates, which leads to transmission
errors in the original code.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
By ci
- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

---------

Signed-off-by: nwpu-zxr <zhouxuerong2@huawei.com>
Signed-off-by: wangxiaoteng <wangxiaoteng@huawei.com>
Co-authored-by: nwpu-zxr <zhouxuerong2@huawei.com>
2025-10-11 11:22:23 +08:00

196 lines
7.2 KiB
Python

from typing import Optional
import torch
from vllm.config import ParallelConfig, get_current_vllm_config
from vllm.distributed.parallel_state import (GroupCoordinator, get_world_group,
init_model_parallel_group)
import vllm_ascend.envs as envs_ascend
from vllm_ascend.ascend_config import get_ascend_config
# Currently, mc2 op need their own group coordinator.
_MC2: Optional[GroupCoordinator] = None
_MLP_TP: Optional[GroupCoordinator] = None
_OTP: Optional[GroupCoordinator] = None
_LMTP: Optional[GroupCoordinator] = None
_P_TP: Optional[GroupCoordinator] = None
def get_mc2_group() -> GroupCoordinator:
assert _MC2 is not None, ("mc2 group is not initialized")
return _MC2
def get_otp_group() -> GroupCoordinator:
assert _OTP is not None, (
"output tensor parallel group is not initialized")
return _OTP
def get_lmhead_tp_group() -> GroupCoordinator:
assert _LMTP is not None, (
"lm head tensor parallel group is not initialized")
return _LMTP
def get_mlp_tp_group() -> GroupCoordinator:
assert _MLP_TP is not None, ("mlp group is not initialized")
return _MLP_TP
def get_p_tp_group() -> GroupCoordinator:
assert _P_TP is not None, (
"distributed prefill tensor parallel group is not initialized")
return _P_TP
def model_parallel_initialized():
return (_MC2 is not None)
def init_ascend_model_parallel(parallel_config: ParallelConfig, ):
if model_parallel_initialized():
return
assert torch.distributed.is_initialized()
world_size = torch.distributed.get_world_size()
backend = torch.distributed.get_backend(get_world_group().device_group)
# The layout of all ranks: ExternalDP * EP
# ExternalDP is the data parallel group that is not part of the model,
# every dp rank can generate independently (in verl integration).
all_ranks = torch.arange(world_size).reshape(
-1, parallel_config.data_parallel_size *
parallel_config.tensor_parallel_size)
pd_tp_ratio = get_ascend_config().pd_tp_ratio
pd_head_ratio = get_ascend_config().pd_head_ratio
global _P_TP
assert _P_TP is None, (
"distributed prefill tensor parallel group is already initialized")
prefill_tensor_model_parallel_size = pd_tp_ratio
# divide alltoall groups
if pd_head_ratio > 1 and get_current_vllm_config(
).kv_transfer_config.is_kv_producer:
num_head_replica = get_ascend_config().num_head_replica
remote_tp_size = parallel_config.tensor_parallel_size // pd_tp_ratio
if num_head_replica <= 1:
group_ranks = all_ranks.view(
-1, prefill_tensor_model_parallel_size).unbind(0)
else:
group_ranks = all_ranks.clone().view(
parallel_config.data_parallel_size, -1,
num_head_replica) # [DP_size, num_head, num_head_replica]
group_ranks = group_ranks.permute(0, 2, 1)
group_ranks = group_ranks.reshape(
-1,
group_ranks.size(-1)) # [DP_size * num_head_replica, num_head]
alltoall_group_size = group_ranks.size(-1) // remote_tp_size
group_ranks = group_ranks.unsqueeze(-1).view(
parallel_config.data_parallel_size, num_head_replica, -1,
alltoall_group_size
) # [DP_size, num_head_replica, num_alltoall_group, alltoall_group_size]
group_ranks = group_ranks.view(-1, alltoall_group_size).unbind(0)
group_ranks = [x.tolist() for x in group_ranks]
local_rank = get_world_group().local_rank
num = next(
(i for i, ranks in enumerate(group_ranks) if local_rank in ranks),
None)
_P_TP = init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name=f"p_tp_{num}")
global _MC2
group_ranks = all_ranks.unbind(0)
group_ranks = [x.tolist() for x in group_ranks]
_MC2 = init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name="mc2")
if envs_ascend.VLLM_ASCEND_ENABLE_MLP_OPTIMIZE:
global _MLP_TP
assert _MLP_TP is None, (
"mlp tensor model parallel group is already initialized")
mlp_tp = parallel_config.data_parallel_size
all_ranks_mlp_head = torch.arange(world_size).reshape(
-1, mlp_tp, parallel_config.pipeline_parallel_size, 1) # noqa
group_ranks = all_ranks_mlp_head.view(-1, mlp_tp).unbind(0)
group_ranks = [x.tolist() for x in group_ranks]
# message queue broadcaster is only used in tensor model parallel group
_MLP_TP = init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name="mlp_tp")
# If oproj tensor parallel size is set, we will create a group for it.
otp_size = get_ascend_config().oproj_tensor_parallel_size
if otp_size is not None:
group_ranks = []
global _OTP
num_oproj_tensor_parallel_groups: int = (world_size // otp_size)
for i in range(num_oproj_tensor_parallel_groups):
ranks = list(range(i * otp_size, (i + 1) * otp_size))
group_ranks.append(ranks)
_OTP = init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name="otp")
lmhead_tensor_parallel_size = get_ascend_config(
).lmhead_tensor_parallel_size
if lmhead_tensor_parallel_size is not None:
group_ranks = []
global _LMTP
num_lmhead_tensor_parallel_groups: int = (world_size //
lmhead_tensor_parallel_size)
for i in range(num_lmhead_tensor_parallel_groups):
ranks = list(
range(i * lmhead_tensor_parallel_size,
(i + 1) * lmhead_tensor_parallel_size))
group_ranks.append(ranks)
_LMTP = init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name="lmheadtp")
def get_mlp_tensor_model_parallel_world_size():
"""Return world size for the tensor model parallel group."""
return get_mlp_tp_group().world_size
def get_mlp_tensor_model_parallel_rank():
"""Return world size for the tensor model parallel group."""
return get_mlp_tp_group().rank_in_group
def destroy_ascend_model_parallel():
global _MC2
if _MC2:
_MC2.destroy()
_MC2 = None
global _MLP_TP
if _MLP_TP:
_MLP_TP.destroy()
_MLP_TP = None
global _LMTP
if _LMTP:
_LMTP.destroy()
_LMTP = None
global _OTP
if _OTP:
_OTP.destroy()
_OTP = None
global _P_TP
if _P_TP:
_P_TP.destroy()
_P_TP = None