Files
xc-llm-ascend/vllm_ascend/distributed/parallel_state.py
zzhxxx dd8571860d [Feature] Support DSA-CP for Hybrid scenario (#5702)
Signed-off-by: zzhx1 <zzh_201018@outlook.com>

### What this PR does / why we need it?
> Extracted from PR #5513
Based on the Sharded-CP feature PR:#4702;
RFC:https://github.com/vllm-project/vllm/issues/30055

### Support FULL_DECODE_ONLY Mode under PD-Mixed Scenario:
Extends DSA-CP to handle the FULL_DECODE_ONLY execution mode when
running in a prefill-decode mixed (PD-mixed) serving environment,
improving throughput and resource utilization for decode-intensive
workloads.
**In pure prefill nodes:**
- Both q_proj and o_proj are sharded across world ranks, using
**broadcast** for weights distribution.

**In PD-mixed nodes (supporting both prefill and decode):**

- q_proj is fully replicated (not sharded) to avoid communication
overhead during decoding.
- o_proj Using the original TP `RowParallelLinear` method to store
weights

**During prefill execution:**
- o_proj forwards through all_gather to collect weights, reconstructing
the complete o_proj weights on each card.

**During decode (graph replay phase):**
- Additional all_to_all (before o_proj) and reduce_scatter (after
o_proj) are introduced to enable sequence-parallel output aggregation
while maintaining correctness under SFA CP.

### benchmark:
- TTFT increased by **527%**
- TPOT increased by **180%**

<img width="1550" height="938" alt="image"
src="https://github.com/user-attachments/assets/9b7a03d8-a3db-4a99-8923-6e5bfcfecf72"
/>


### Does this PR introduce _any_ user-facing change?
None
### How was this patch tested?

- vLLM version: v0.13.0
- vLLM main:
2f4e6548ef

---------

Signed-off-by: zzhx1 <zzh_201018@outlook.com>
Signed-off-by: zzhxx <zhangzihang23@mails.ucas.ac.cn>
Co-authored-by: clrs97 <524936896@qq.com>
2026-01-22 10:12:09 +08:00

369 lines
14 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_tp_group,
get_world_group,
init_model_parallel_group)
from vllm_ascend.ascend_config import get_ascend_config
from vllm_ascend.utils import enable_dsa_cp_with_layer_shard, flashcomm2_enable
# Currently, mc2 op need their own group coordinator.
_MC2: Optional[GroupCoordinator] = None
# Module specific tensor parallel groups
_MLP_TP: Optional[GroupCoordinator] = None
_OTP: Optional[GroupCoordinator] = None
_LMTP: Optional[GroupCoordinator] = None
_EMBED_TP: Optional[GroupCoordinator] = None
# flashcomm specific groups
_FLASHCOMM2_OTP: Optional[GroupCoordinator] = None
_FLASHCOMM2_ODP: Optional[GroupCoordinator] = None
_FC3_QUANT_X: Optional[GroupCoordinator] = None
# shard_weight across rank groups
_SHARD_WEIGHT: Optional[GroupCoordinator] = None
_P_TP: Optional[GroupCoordinator] = 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)
global_tp_size = parallel_config.tensor_parallel_size
global_dp_size = parallel_config.data_parallel_size
global_pp_size = parallel_config.pipeline_parallel_size
# 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, global_dp_size * parallel_config.prefill_context_parallel_size *
global_tp_size)
#TODO: all_ranks should be the same as vllm_all_ranks, all_ranks needs to be removed in the future.
vllm_all_ranks = torch.arange(world_size).reshape(
-1,
global_dp_size,
global_pp_size,
parallel_config.prefill_context_parallel_size,
global_tp_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 = global_tp_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(
global_dp_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(
global_dp_size, num_head_replica, -1, alltoall_group_size
) # [DP_size, num_head_replica, num_alltoall_group, alltoall_group_size]
group_ranks = group_ranks.reshape(-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")
# Initialize fine-grained TP process groups on Ascend for four components:
# 1. LM Head: output logits projection (`lmhead_tensor_parallel_size`)
# 2. O Proj: attention output projection (`oproj_tensor_parallel_size`)
# 3. Embedding: The token embedding table at the input of the model (`embedding_tensor_parallel_size`)
# 4. MLP: feed-forward network in transformer blocks (`mlp_tensor_parallel_size`)
_group_cache = {}
def _create_or_get_group(group_size: int,
group_name: str) -> GroupCoordinator:
if group_size is None:
return None
if group_size not in _group_cache:
rank_grid = torch.arange(world_size).reshape(
global_pp_size, global_dp_size, global_tp_size)
num_chunks = global_dp_size // group_size
group_ranks = []
for pp_idx in range(global_pp_size):
stage_ranks = rank_grid[pp_idx] # (dp, tp)
for chunk in range(num_chunks):
for tp_idx in range(global_tp_size):
group = stage_ranks[chunk * group_size:(chunk + 1) *
group_size, tp_idx].tolist()
group_ranks.append(group)
pg = init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name=group_name)
_group_cache[group_size] = pg
return _group_cache[group_size]
otp_size = get_ascend_config(
).finegrained_tp_config.oproj_tensor_parallel_size
lmhead_tp_size = get_ascend_config(
).finegrained_tp_config.lmhead_tensor_parallel_size
embedding_tp_size = get_ascend_config(
).finegrained_tp_config.embedding_tensor_parallel_size
mlp_tp_size = get_ascend_config(
).finegrained_tp_config.mlp_tensor_parallel_size
global _OTP, _LMTP, _EMBED_TP, _MLP_TP
if otp_size > 0:
_OTP = _create_or_get_group(otp_size, "otp")
if lmhead_tp_size > 0:
_LMTP = _create_or_get_group(lmhead_tp_size, "lmheadtp")
if embedding_tp_size > 0:
_EMBED_TP = _create_or_get_group(embedding_tp_size, "emtp")
if mlp_tp_size > 0:
_MLP_TP = _create_or_get_group(mlp_tp_size, "mlptp")
# TODO: Extract and unify the logic across different communication group.
flashcomm2_otp_group_ranks = []
if flashcomm2_enable():
flashcomm2_otp_size = get_ascend_config(
).flashcomm2_oproj_tensor_parallel_size
num_fc2_oproj_tensor_parallel_groups: int = (global_tp_size //
flashcomm2_otp_size)
global _FLASHCOMM2_OTP
global _FLASHCOMM2_ODP
_FLASHCOMM2_OTP = None
_FLASHCOMM2_ODP = get_tp_group()
if flashcomm2_otp_size > 1:
odp_group_ranks: list[list[int]] = [
[] for _ in range(flashcomm2_otp_size * global_dp_size *
global_pp_size)
]
for dp_group_index in range(global_dp_size):
for pp_group_index in range(global_pp_size):
dp_pp_serial_index = dp_group_index * global_pp_size + pp_group_index
tp_base_rank = dp_pp_serial_index * global_tp_size
odp_base_index = dp_pp_serial_index * flashcomm2_otp_size
for i in range(num_fc2_oproj_tensor_parallel_groups):
ranks = []
for j in range(flashcomm2_otp_size):
tp_local_rank = i + j * num_fc2_oproj_tensor_parallel_groups
assert tp_local_rank < global_tp_size
global_rank = tp_base_rank + tp_local_rank
ranks.append(global_rank)
odp_group_index = odp_base_index + j
odp_group_ranks[odp_group_index].append(
global_rank)
flashcomm2_otp_group_ranks.append(ranks)
_FLASHCOMM2_OTP = init_model_parallel_group(
flashcomm2_otp_group_ranks,
get_world_group().local_rank,
backend,
group_name="flashcomm2_otp")
_FLASHCOMM2_ODP = init_model_parallel_group(
odp_group_ranks,
get_world_group().local_rank,
backend,
group_name="flashcomm2_odp")
def create_shard_weight_group(
module_tp_group_ranks: None) -> GroupCoordinator:
# Argument module_tp_group_ranks: The module specific tensor parallel group.
# There are three situations.
# 1. If it is None, then the TP_size of the specific module is 1 and is replicated linear layer.
# 2. If it is not None, and the module tp_group is same as the global tp_group.
# 3. If it is not None, and the module tp_group is different from the global tp_group.(eg. flashcomm2_otp)
group_ranks = []
pp_group_ranks = vllm_all_ranks.transpose(2, 4).reshape(
-1, global_pp_size)
if module_tp_group_ranks is None:
# If it is None, then the TP_size of this shard weight is 1.
shard_weight_group_ranks = pp_group_ranks.transpose(0, 1).unbind(0)
group_ranks = [x.tolist() for x in shard_weight_group_ranks]
else:
# combine standard tp group and non-standard tp group to build shard_weight comm_group
module_tp_tanspose_ranks = module_tp_group_ranks.transpose(0, 1)
G = world_size // (global_pp_size * module_tp_group_ranks.size(1))
shard_weight_group_ranks = torch.stack(
[t.view(global_pp_size, G) for t in module_tp_tanspose_ranks],
dim=1)
group_ranks = shard_weight_group_ranks.view(-1, G).tolist()
return init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name="shard_weight")
# Create shard weight group if enabled
if get_ascend_config().layer_sharding is not None:
global _SHARD_WEIGHT
if flashcomm2_enable():
if len(flashcomm2_otp_group_ranks) == 0:
FC2_group_ranks = None
else:
FC2_group_ranks = torch.tensor(
flashcomm2_otp_group_ranks).squeeze(0)
_SHARD_WEIGHT = create_shard_weight_group(FC2_group_ranks)
elif enable_dsa_cp_with_layer_shard():
# For dsa_cp, all shard layers are replicated.
_SHARD_WEIGHT = create_shard_weight_group(None)
else:
# For standard tp, use global tp group_ranks
tp_group_ranks = vllm_all_ranks.view(-1, global_tp_size)
_SHARD_WEIGHT = create_shard_weight_group(tp_group_ranks)
if get_ascend_config().multistream_overlap_gate:
global _FC3_QUANT_X
group_ranks = all_ranks.unbind(0)
group_ranks = [x.tolist() for x in group_ranks]
_FC3_QUANT_X = init_model_parallel_group(group_ranks,
get_world_group().local_rank,
backend,
group_name="fc3_quant_x")
def model_parallel_initialized():
return (_MC2 is not None)
def get_mc2_group() -> GroupCoordinator:
assert _MC2 is not None, ("mc2 group is not initialized")
return _MC2
def get_mlp_tp_group() -> GroupCoordinator:
assert _MLP_TP is not None, ("mlp group is not initialized")
return _MLP_TP
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_embed_tp_group() -> GroupCoordinator:
assert _EMBED_TP is not None, ("emtp group is not initialized")
return _EMBED_TP
def get_flashcomm2_otp_group() -> GroupCoordinator:
return _FLASHCOMM2_OTP
def get_flashcomm2_odp_group() -> GroupCoordinator:
assert _FLASHCOMM2_ODP is not None, (
"output data parallel group for flashcomm2 is not initialized")
return _FLASHCOMM2_ODP
def get_shard_weight_group() -> GroupCoordinator:
assert _SHARD_WEIGHT is not None, (
"output shard weight parallel group for flashcomm2 is not initialized")
return _SHARD_WEIGHT
def get_p_tp_group() -> GroupCoordinator:
assert _P_TP is not None, (
"distributed prefill tensor parallel group is not initialized")
return _P_TP
def get_fc3_quant_x_group() -> GroupCoordinator:
assert _FC3_QUANT_X is not None, ("fc3 quant x group is not initialized")
return _FC3_QUANT_X
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 _EMBED_TP
if _EMBED_TP:
_EMBED_TP.destroy()
_EMBED_TP = None
global _OTP
if _OTP:
_OTP.destroy()
_OTP = None
global _P_TP
if _P_TP:
_P_TP.destroy()
_P_TP = None
global _FLASHCOMM2_OTP
if _FLASHCOMM2_OTP and get_ascend_config(
).flashcomm2_oproj_tensor_parallel_size != 1:
_FLASHCOMM2_OTP.destroy()
_FLASHCOMM2_OTP = None
global _FLASHCOMM2_ODP
if _FLASHCOMM2_ODP and get_ascend_config(
).flashcomm2_oproj_tensor_parallel_size != 1:
_FLASHCOMM2_ODP.destroy()
_FLASHCOMM2_ODP = None
global _SHARD_WEIGHT
if _SHARD_WEIGHT:
_SHARD_WEIGHT.destroy()
_SHARD_WEIGHT = None
global _FC3_QUANT_X
if _FC3_QUANT_X:
_FC3_QUANT_X.destroy()
_FC3_QUANT_X = None