Files
vllm-omni/vllm_omni/diffusion/layers/norm.py
T
fan2956andgcanlin f1cb4ebe4c [PERF] Wan2.2 support rmsnorm fused op (#2583)
Signed-off-by: fan2956 <zhoufan53@huawei.com>
Signed-off-by: gcanlin <canlinguosdu@gmail.com>
Co-authored-by: gcanlin <canlinguosdu@gmail.com>
2026-04-16 03:21:34 -07:00

111 lines
3.3 KiB
Python

from importlib.util import find_spec
import torch
import torch.nn as nn
import torch.nn.functional as F
from vllm.logger import init_logger
from vllm_omni.diffusion.layers.custom_op import CustomOp
logger = init_logger(__name__)
_HAS_MINDIESD = find_spec("mindiesd") is not None
class LayerNorm(nn.LayerNorm, CustomOp):
"""
LayerNorm implementation that inherits from both ``nn.LayerNorm`` and ``CustomOp``.
NPU:
Uses ``mindiesd.fast_layernorm(self, x)`` when MindIE-SD is installed.
CUDA / HIP / XPU / native:
Falls back to FP32 nn.LayerNorm implementation.
"""
def __init__(self, dim: int, eps: float = 1e-6, elementwise_affine: bool = True):
super().__init__(normalized_shape=dim, eps=eps, elementwise_affine=elementwise_affine)
# CustomOp.__init__ cannot be called here because it would re-run
# nn.Module initialization and clear LayerNorm parameters.
self._forward_method = CustomOp.dispatch_forward(self)
def forward(self, x: torch.Tensor) -> torch.Tensor:
return self._forward_method(x)
def forward_cuda(self, x: torch.Tensor) -> torch.Tensor:
return self.forward_native(x)
def forward_hip(self, x: torch.Tensor) -> torch.Tensor:
return self.forward_native(x)
def forward_xpu(self, x: torch.Tensor) -> torch.Tensor:
return self.forward_native(x)
def forward_npu(self, x: torch.Tensor) -> torch.Tensor:
if _HAS_MINDIESD:
try:
from mindiesd import fast_layernorm
return fast_layernorm(self, x)
except ImportError as e:
logger.warning_once(
"mindiesd.fast_layernorm import failed, falling back to FP32 layer_norm: %s",
e,
)
return self.forward_native(x)
def forward_native(self, x: torch.Tensor) -> torch.Tensor:
origin_dtype = x.dtype
return F.layer_norm(
x.float(),
self.normalized_shape,
self.weight.float() if self.weight is not None else None,
self.bias.float() if self.bias is not None else None,
self.eps,
).to(origin_dtype)
class RMSNorm(CustomOp):
def __init__(self, hidden_size: int, eps: float = 1e-6) -> None:
super().__init__()
self.weight = nn.Parameter(torch.ones(hidden_size))
self.variance_epsilon = eps
def forward_cuda(
self,
x: torch.Tensor,
) -> torch.Tensor:
return self.forward_native(x)
def forward_hip(
self,
x: torch.Tensor,
) -> torch.Tensor:
return self.forward_native(x)
def forward_npu(
self,
x: torch.Tensor,
) -> torch.Tensor:
import torch_npu
output = torch_npu.npu_rms_norm(x, gamma=self.weight, epsilon=self.variance_epsilon)[0]
return output
def forward_xpu(
self,
x: torch.Tensor,
) -> torch.Tensor:
return self.forward_native(x)
def forward_native(
self,
x: torch.Tensor,
) -> torch.Tensor:
input_dtype = x.dtype
x = x.to(torch.float32)
variance = x.pow(2).mean(-1, keepdim=True)
out = x * torch.rsqrt(variance + self.variance_epsilon)
out = self.weight.to(torch.float32) * out
return out.to(input_dtype)