[Refactor] MLP weight prefetch to consistency with MoE Model's prefetching in terms of code and usage (#6442)

### What this PR does / why we need it?
Refactor MLP weight prefetch to consistency with MoE Model's prefetching
in terms of code and usage.
Environments VLLM_ASCEND_ENABLE_PREFETCH_MLP,
VLLM_ASCEND_MLP_DOWN_PREFETCH_SIZE and
VLLM_ASCEND_MLP_GATE_UP_PREFETCH_SIZE is removed, usage as following:

--additional-config '{"weight_prefetch_config": { "enabled": true,
"prefetch_ratio": {"mlp": { "gate_up": 1.0, "down": 1.0} }}}'

### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

- vLLM version: v0.14.1
- vLLM main:
dc917cceb8

---------

Signed-off-by: leo-pony <nengjunma@outlook.com>
This commit is contained in:
Nengjun Ma
2026-02-04 09:08:18 +08:00
committed by GitHub
parent fa56abea9f
commit 78fad4e348
18 changed files with 250 additions and 171 deletions

View File

@@ -110,33 +110,6 @@ def _maybe_pad_and_reduce_impl(x: torch.Tensor,
0)
def _maybe_prefetch_mlp_gate_up_proj_impl(x_dependency: torch.Tensor,
prefix: str) -> None:
try:
forward_context = get_forward_context()
except AssertionError:
return
if not getattr(forward_context, 'prefetch_mlp_enabled', False):
return
model_instance = forward_context.model_instance
weight_prefetch_stream = prefetch_stream()
layer_idx = int(prefix.split('.')[2])
# start point of gate_up_proj weight prefetch
if prefix.split('.')[-2] == "self_attn":
forward_context.prefetch_mlp_gate_up_proj = True
if forward_context.prefetch_mlp_gate_up_proj:
weight_prefetch_stream.wait_stream(torch.npu.current_stream())
with torch.npu.stream(weight_prefetch_stream):
mlp_gate_up_prefetch_size = envs_ascend.VLLM_ASCEND_MLP_GATE_UP_PREFETCH_SIZE
torch_npu.npu_prefetch(
model_instance.model.layers[layer_idx].mlp.gate_up_proj.weight,
x_dependency, mlp_gate_up_prefetch_size)
return
def _maybe_all_gather_and_maybe_unpad_fake(
x: torch.Tensor,
label: bool,
@@ -164,63 +137,6 @@ def _maybe_pad_and_reduce_fake(x: torch.Tensor,
return x
def _maybe_prefetch_mlp_gate_up_proj_impl_fake(x_dependency: torch.Tensor,
prefix: str) -> None:
return
def _maybe_prefetch_mlp_down_proj_impl(x_dependency: torch.Tensor) -> None:
try:
forward_context = get_forward_context()
except AssertionError:
return
if not getattr(forward_context, 'prefetch_mlp_enabled', False):
return
forward_context.prefetch_mlp_down_proj = True
model_instance = forward_context.model_instance
weight_prefetch_stream = prefetch_stream()
layer_idx = forward_context.layer_idx
# start point of down_proj weight prefetch
weight_prefetch_stream.wait_stream(torch.npu.current_stream())
with torch.npu.stream(weight_prefetch_stream):
mlp_down_prefetch_size = envs_ascend.VLLM_ASCEND_MLP_DOWN_PREFETCH_SIZE
torch_npu.npu_prefetch(
model_instance.model.layers[layer_idx].mlp.down_proj.weight,
x_dependency, mlp_down_prefetch_size)
forward_context.layer_idx += 1
return
def _maybe_prefetch_mlp_down_proj_impl_fake(
x_dependency: torch.Tensor) -> None:
return
def _maybe_wait_prefetch_done_impl(x: torch.Tensor) -> None:
try:
forward_context = get_forward_context()
except AssertionError:
return
if not getattr(forward_context, 'prefetch_mlp_enabled', False):
return
if forward_context.prefetch_mlp_gate_up_proj or \
forward_context.prefetch_mlp_down_proj:
weight_prefetch_stream = prefetch_stream()
# wait until prefetch done
torch.npu.current_stream().wait_stream(weight_prefetch_stream)
forward_context.prefetch_mlp_gate_up_proj = False
forward_context.prefetch_mlp_down_proj = False
return
def _maybe_wait_prefetch_done_impl_fake(x: torch.Tensor) -> None:
return
def _prefetch_preprocess_impl(weight: torch.Tensor, start_flag: torch.Tensor,
max_weight_size: int) -> None:
calculation_stream = torch_npu.npu.current_stream()
@@ -331,24 +247,6 @@ direct_register_custom_op(op_name="maybe_pad_and_reduce",
mutates_args=[],
dispatch_key="PrivateUse1")
direct_register_custom_op(op_name="maybe_prefetch_mlp_gate_up_proj",
op_func=_maybe_prefetch_mlp_gate_up_proj_impl,
fake_impl=_maybe_prefetch_mlp_gate_up_proj_impl_fake,
mutates_args=[],
dispatch_key="PrivateUse1")
direct_register_custom_op(op_name="maybe_prefetch_mlp_down_proj",
op_func=_maybe_prefetch_mlp_down_proj_impl,
fake_impl=_maybe_prefetch_mlp_down_proj_impl_fake,
mutates_args=[],
dispatch_key="PrivateUse1")
direct_register_custom_op(op_name="maybe_wait_prefetch_done",
op_func=_maybe_wait_prefetch_done_impl,
fake_impl=_maybe_wait_prefetch_done_impl_fake,
mutates_args=[],
dispatch_key="PrivateUse1")
direct_register_custom_op(op_name="prefetch_preprocess",
op_func=_prefetch_preprocess_impl,
fake_impl=_prefetch_preprocess_impl_fake,