Add xavier_uniform init of MNVC hybrid attention modules. Small improvement in training stability.

Author: rwightman

timm/layers/attention2d.py

@@ -205,6 +205,16 @@ def __init__(
 
         self.einsum = False
 
+    def init_weights(self):
+        # using xavier appeared to improve stability for mobilenetv4 hybrid w/ this layer
+        nn.init.xavier_uniform_(self.query.proj.weight)
+        nn.init.xavier_uniform_(self.key.proj.weight)
+        nn.init.xavier_uniform_(self.value.proj.weight)
+        if self.kv_stride > 1:
+            nn.init.xavier_uniform_(self.key.down_conv.weight)
+            nn.init.xavier_uniform_(self.value.down_conv.weight)
+        nn.init.xavier_uniform_(self.output.proj.weight)
+
     def _reshape_input(self, t: torch.Tensor):
         """Reshapes a tensor to three dimensions, keeping the batch and channels."""
         s = t.shape

timm/models/_efficientnet_builder.py

@@ -16,8 +16,9 @@
 
 import torch.nn as nn
 
-from ._efficientnet_blocks import *
 from timm.layers import CondConv2d, get_condconv_initializer, get_act_layer, get_attn, make_divisible, LayerType
+from ._efficientnet_blocks import *
+from ._manipulate import named_modules
 
 __all__ = ["EfficientNetBuilder", "decode_arch_def", "efficientnet_init_weights",
            'resolve_bn_args', 'resolve_act_layer', 'round_channels', 'BN_MOMENTUM_TF_DEFAULT', 'BN_EPS_TF_DEFAULT']
@@ -569,3 +570,7 @@ def efficientnet_init_weights(model: nn.Module, init_fn=None):
     for n, m in model.named_modules():
         init_fn(m, n)
 
+    # iterate and call any module.init_weights() fn, children first
+    for n, m in named_modules(model):
+        if hasattr(m, 'init_weights'):
+            m.init_weights()