[Perf] Delete redundant operations in model_runner and forward_context (#3677)

### What this PR does / why we need it?

Remove redundant operations from `model_runner` and `forward_context`.
This optimization can significantly reduce the idle time (bubble) before
decoding when running models with small parameter counts (e.g.,
Qwen/Qwen2.5-0.5B).

Testing on 800I A2, bubble is reduced from 3.8ms to 2.8ms :
Before
<img width="1655" height="696" alt="image"
src="https://github.com/user-attachments/assets/d7608e52-2438-46dd-8fc9-391fd6274495"
/>

After
<img width="1607" height="774" alt="image"
src="https://github.com/user-attachments/assets/56daf081-2dba-4d2e-99d4-e055187d9806"
/>

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?


- vLLM version: v0.11.0rc3
- vLLM main:
https://github.com/vllm-project/vllm/commit/releases/v0.11.1

---------

Signed-off-by: realliujiaxu <realliujiaxu@163.com>
This commit is contained in:
realliujiaxu
2025-10-29 15:59:55 +08:00
committed by GitHub
parent 0d1859af08
commit 74191864b7
5 changed files with 34 additions and 25 deletions

View File

@@ -68,6 +68,8 @@ def test_select_moe_comm_method(soc_version, enable_expert_parallel,
with patch('vllm_ascend.worker.model_runner_v1.get_ascend_soc_version',
return_value=soc_version), \
patch('vllm_ascend.worker.model_runner_v1.is_global_first_rank',
return_value=True), \
patch('vllm_ascend.worker.model_runner_v1.is_moe_model',
return_value=True):
# Bind the real method to the mock object
@@ -102,6 +104,8 @@ def test_select_moe_comm_method_unsupported_soc():
return_value=unsupported_soc), \
patch('vllm_ascend.worker.model_runner_v1.is_global_first_rank',
return_value=True), \
patch('vllm_ascend.worker.model_runner_v1.is_moe_model',
return_value=True), \
pytest.raises(ValueError, match=f"Unsupported soc_version: {unsupported_soc}"):
NPUModelRunner._select_moe_comm_method(mock_runner, 100, False)

View File

@@ -11,7 +11,8 @@ from vllm.forward_context import (BatchDescriptor, get_forward_context,
set_forward_context)
import vllm_ascend.envs as envs_ascend
from vllm_ascend.utils import enable_sp, is_moe_model, version_check
from vllm_ascend.utils import (enable_sp, has_layer_idx, is_moe_model,
version_check)
if TYPE_CHECKING:
from vllm_ascend.ops.weight_prefetch import WeightPrefetchMethod
@@ -137,9 +138,7 @@ def set_ascend_forward_context(
# set layer_idx to enable optimization features that depend on this information.
# This is only applicable to models that contain these necessary attributes.
forward_context.layer_idx = None
if model_instance is not None and \
hasattr(model_instance, "model") and \
hasattr(model_instance.model, "start_layer"):
if has_layer_idx(model_instance):
forward_context.layer_idx = model_instance.model.start_layer
# TODO(rjg-lyh): refactor mlp weight prefetch method

View File

@@ -37,7 +37,7 @@ _MoECommMethods: Dict[Optional[MoECommType], MoECommMethod] = {}
def get_moe_comm_method(
moe_comm_type: Optional[MoECommType]) -> Optional[MoECommMethod]:
return _MoECommMethods.get(moe_comm_type)
return _MoECommMethods.get(moe_comm_type, None)
def setup_moe_comm_method(moe_config):

View File

@@ -58,6 +58,7 @@ _DEFAULT_BUFFER_SIZE = 200
_MIN_DP_BUFFER_SIZE = 50
_IS_MOE_MODEL = None
_ENABLE_SP = None
_HAS_LAYER_IDX = None
def is_310p():
@@ -807,3 +808,14 @@ def version_check():
if full_date >= "20250919":
return True
return False
def has_layer_idx(model_instance: torch.nn.Module) -> bool:
if model_instance is None:
return False
global _HAS_LAYER_IDX
if _HAS_LAYER_IDX is None:
_HAS_LAYER_IDX = hasattr(model_instance, "model") and \
hasattr(model_instance.model, "start_layer")
return _HAS_LAYER_IDX

View File

@@ -136,7 +136,7 @@ from vllm_ascend.spec_decode.mtp_proposer import MtpProposer
from vllm_ascend.utils import (ACL_FORMAT_FRACTAL_ND, ACL_FORMAT_FRACTAL_NZ,
AscendSocVersion, ProfileExecuteDuration,
enable_sp, get_ascend_soc_version, is_310p,
is_enable_nz, lmhead_tp_enable,
is_enable_nz, is_moe_model, lmhead_tp_enable,
prefill_context_parallel_enable,
vllm_version_is)
from vllm_ascend.worker.npu_input_batch import CachedRequestState, InputBatch
@@ -515,11 +515,14 @@ class NPUModelRunner(LoRAModelRunnerMixin):
self.in_profile_run = False
self._init_mc2_tokens_capacity()
if is_moe_model(vllm_config):
self.reserved_mc2_mask = torch.zeros(
self.mc2_tokens_capacity,
dtype=torch.bool,
device=self.device,
)
else:
self.reserved_mc2_mask = None
self.dynamic_eplb = self.ascend_config.dynamic_eplb or self.ascend_config.expert_map_record_path
if self.dynamic_eplb:
EPLBParamUtils.check_dynamic_eplb(self.ascend_config.dynamic_eplb)
@@ -1497,9 +1500,7 @@ class NPUModelRunner(LoRAModelRunnerMixin):
self.query_lens = torch.from_numpy(num_scheduled_tokens)
# Copy the tensors to the NPU.
self.input_ids[:total_num_scheduled_tokens].copy_(
self.input_ids_cpu[:total_num_scheduled_tokens], non_blocking=True)
self._prepare_input_ids(total_num_scheduled_tokens, cu_num_tokens)
self.positions_cpu[total_num_scheduled_tokens:num_input_tokens].zero_()
self.positions[:num_input_tokens].copy_(
self.positions_cpu[:num_input_tokens], non_blocking=True)
@@ -1521,16 +1522,6 @@ class NPUModelRunner(LoRAModelRunnerMixin):
self._update_graph_pad_size(with_prefill, maybe_padded_num_tokens)
attn_metadata: dict[str, Any] = {}
# Prepare input_ids
token_indices = (positions_np +
req_indices * self.input_batch.token_ids_cpu.shape[1])
torch.index_select(self.input_batch.token_ids_cpu_tensor.flatten(),
0,
torch.from_numpy(token_indices),
out=self.input_ids_cpu[:total_num_scheduled_tokens])
# Copy the tensors to the NPU.
self._prepare_input_ids(total_num_scheduled_tokens, cu_num_tokens)
# _prepare_inputs may reorder the batch, so we must gather
# multi-modal outputs after that to ensure the correct order
if self.is_multimodal_model:
@@ -2075,7 +2066,7 @@ class NPUModelRunner(LoRAModelRunnerMixin):
)
def _select_moe_comm_method(self, num_tokens: int,
with_prefill: bool) -> MoECommType:
with_prefill: bool) -> Optional[MoECommType]:
"""1. If expert parallel is not enabled, we use all-gather since MC2 and all-to-all
are designed for expert parallelism.
2. If expert parallel is enabled, we need to consider the soc version and the
@@ -2098,6 +2089,9 @@ class NPUModelRunner(LoRAModelRunnerMixin):
Returns:
MoECommType: The selected MoE communication method.
"""
if not is_moe_model(self.vllm_config):
return None
soc_version = get_ascend_soc_version()
quant_type = getattr(self.vllm_config.model_config.hf_config,
'moe_quantize', None)