Merge pull request #2092 from huggingface/mesa_ema

ModelEMAV3 + MESA experiments

timm/data/transforms.py

@@ -32,16 +32,12 @@ class ToNumpy:
 
 
 class ToTensor:
-
+    """ ToTensor with no rescaling of values"""
     def __init__(self, dtype=torch.float32):
         self.dtype = dtype
 
     def __call__(self, pil_img):
-        np_img = np.array(pil_img, dtype=np.uint8)
+        return F.pil_to_tensor(pil_img).to(dtype=self.dtype)
-        if np_img.ndim < 3:
-            np_img = np.expand_dims(np_img, axis=-1)
-        np_img = np.rollaxis(np_img, 2)  # HWC to CHW
-        return torch.from_numpy(np_img).to(dtype=self.dtype)
 
 
 # Pillow is deprecating the top-level resampling attributes (e.g., Image.BILINEAR) in

timm/layers/classifier.py

@@ -180,10 +180,10 @@ class NormMlpClassifierHead(nn.Module):
         self.drop = nn.Dropout(drop_rate)
         self.fc = linear_layer(self.num_features, num_classes) if num_classes > 0 else nn.Identity()
 
-    def reset(self, num_classes, global_pool=None):
+    def reset(self, num_classes, pool_type=None):
-        if global_pool is not None:
+        if pool_type is not None:
-            self.global_pool = SelectAdaptivePool2d(pool_type=global_pool)
+            self.global_pool = SelectAdaptivePool2d(pool_type=pool_type)
-            self.flatten = nn.Flatten(1) if global_pool else nn.Identity()
+            self.flatten = nn.Flatten(1) if pool_type else nn.Identity()
         self.use_conv = self.global_pool.is_identity()
         linear_layer = partial(nn.Conv2d, kernel_size=1) if self.use_conv else nn.Linear
         if self.hidden_size:

timm/layers/create_act.py

@@ -148,7 +148,7 @@ def get_act_layer(name: Union[Type[nn.Module], str] = 'relu'):
     return _ACT_LAYER_DEFAULT[name]
 
 
-def create_act_layer(name: Union[nn.Module, str], inplace=None, **kwargs):
+def create_act_layer(name: Union[Type[nn.Module], str], inplace=None, **kwargs):
     act_layer = get_act_layer(name)
     if act_layer is None:
         return None

timm/models/__init__.py

@@ -39,6 +39,7 @@ from .mobilevit import *
 from .mvitv2 import *
 from .nasnet import *
 from .nest import *
+from .nextvit import *
 from .nfnet import *
 from .pit import *
 from .pnasnet import *

timm/models/davit.py

@@ -547,6 +547,17 @@ class DaVit(nn.Module):
             if isinstance(m, nn.Linear) and m.bias is not None:
                 nn.init.constant_(m.bias, 0)
 
+    @torch.jit.ignore
+    def group_matcher(self, coarse=False):
+        return dict(
+            stem=r'^stem',  # stem and embed
+            blocks=r'^stages\.(\d+)' if coarse else [
+                (r'^stages\.(\d+).downsample', (0,)),
+                (r'^stages\.(\d+)\.blocks\.(\d+)', None),
+                (r'^norm_pre', (99999,)),
+            ]
+        )
+
     @torch.jit.ignore
     def set_grad_checkpointing(self, enable=True):
         self.grad_checkpointing = enable
@@ -558,7 +569,7 @@ class DaVit(nn.Module):
         return self.head.fc
 
     def reset_classifier(self, num_classes, global_pool=None):
-        self.head.reset(num_classes, global_pool=global_pool)
+        self.head.reset(num_classes, global_pool)
 
     def forward_features(self, x):
         x = self.stem(x)

timm/models/nextvit.py

@@ -0,0 +1,685 @@
+""" Next-ViT
+
+As described in https://arxiv.org/abs/2207.05501
+
+Next-ViT model defs and weights adapted from https://github.com/bytedance/Next-ViT, original copyright below
+"""
+# Copyright (c) ByteDance Inc. All rights reserved.
+from functools import partial
+
+import torch
+import torch.nn.functional as F
+from torch import nn
+
+from timm.data import IMAGENET_DEFAULT_MEAN, IMAGENET_DEFAULT_STD
+from timm.layers import DropPath, trunc_normal_, ConvMlp, get_norm_layer, get_act_layer, use_fused_attn
+from timm.layers import ClassifierHead
+from ._builder import build_model_with_cfg
+from ._features_fx import register_notrace_function
+from ._manipulate import checkpoint_seq
+from ._registry import generate_default_cfgs, register_model
+
+
+def merge_pre_bn(module, pre_bn_1, pre_bn_2=None):
+    """ Merge pre BN to reduce inference runtime.
+    """
+    weight = module.weight.data
+    if module.bias is None:
+        zeros = torch.zeros(module.out_chs, device=weight.device).type(weight.type())
+        module.bias = nn.Parameter(zeros)
+    bias = module.bias.data
+    if pre_bn_2 is None:
+        assert pre_bn_1.track_running_stats is True, "Unsupported bn_module.track_running_stats is False"
+        assert pre_bn_1.affine is True, "Unsupported bn_module.affine is False"
+
+        scale_invstd = pre_bn_1.running_var.add(pre_bn_1.eps).pow(-0.5)
+        extra_weight = scale_invstd * pre_bn_1.weight
+        extra_bias = pre_bn_1.bias - pre_bn_1.weight * pre_bn_1.running_mean * scale_invstd
+    else:
+        assert pre_bn_1.track_running_stats is True, "Unsupported bn_module.track_running_stats is False"
+        assert pre_bn_1.affine is True, "Unsupported bn_module.affine is False"
+
+        assert pre_bn_2.track_running_stats is True, "Unsupported bn_module.track_running_stats is False"
+        assert pre_bn_2.affine is True, "Unsupported bn_module.affine is False"
+
+        scale_invstd_1 = pre_bn_1.running_var.add(pre_bn_1.eps).pow(-0.5)
+        scale_invstd_2 = pre_bn_2.running_var.add(pre_bn_2.eps).pow(-0.5)
+
+        extra_weight = scale_invstd_1 * pre_bn_1.weight * scale_invstd_2 * pre_bn_2.weight
+        extra_bias = (
+                scale_invstd_2 * pre_bn_2.weight
+                * (pre_bn_1.bias - pre_bn_1.weight * pre_bn_1.running_mean * scale_invstd_1 - pre_bn_2.running_mean)
+                + pre_bn_2.bias
+        )
+
+    if isinstance(module, nn.Linear):
+        extra_bias = weight @ extra_bias
+        weight.mul_(extra_weight.view(1, weight.size(1)).expand_as(weight))
+    elif isinstance(module, nn.Conv2d):
+        assert weight.shape[2] == 1 and weight.shape[3] == 1
+        weight = weight.reshape(weight.shape[0], weight.shape[1])
+        extra_bias = weight @ extra_bias
+        weight.mul_(extra_weight.view(1, weight.size(1)).expand_as(weight))
+        weight = weight.reshape(weight.shape[0], weight.shape[1], 1, 1)
+    bias.add_(extra_bias)
+
+    module.weight.data = weight
+    module.bias.data = bias
+
+
+class ConvNormAct(nn.Module):
+    def __init__(
+            self,
+            in_chs,
+            out_chs,
+            kernel_size=3,
+            stride=1,
+            groups=1,
+            norm_layer=nn.BatchNorm2d,
+            act_layer=nn.ReLU,
+    ):
+        super(ConvNormAct, self).__init__()
+        self.conv = nn.Conv2d(
+            in_chs, out_chs, kernel_size=kernel_size, stride=stride,
+            padding=1, groups=groups, bias=False)
+        self.norm = norm_layer(out_chs)
+        self.act = act_layer()
+
+    def forward(self, x):
+        x = self.conv(x)
+        x = self.norm(x)
+        x = self.act(x)
+        return x
+
+
+def _make_divisible(v, divisor, min_value=None):
+    if min_value is None:
+        min_value = divisor
+    new_v = max(min_value, int(v + divisor / 2) // divisor * divisor)
+    # Make sure that round down does not go down by more than 10%.
+    if new_v < 0.9 * v:
+        new_v += divisor
+    return new_v
+
+
+class PatchEmbed(nn.Module):
+    def __init__(self,
+            in_chs,
+            out_chs,
+            stride=1,
+            norm_layer = nn.BatchNorm2d,
+    ):
+        super(PatchEmbed, self).__init__()
+
+        if stride == 2:
+            self.pool = nn.AvgPool2d((2, 2), stride=2, ceil_mode=True, count_include_pad=False)
+            self.conv = nn.Conv2d(in_chs, out_chs, kernel_size=1, stride=1, bias=False)
+            self.norm = norm_layer(out_chs)
+        elif in_chs != out_chs:
+            self.pool = nn.Identity()
+            self.conv = nn.Conv2d(in_chs, out_chs, kernel_size=1, stride=1, bias=False)
+            self.norm = norm_layer(out_chs)
+        else:
+            self.pool = nn.Identity()
+            self.conv = nn.Identity()
+            self.norm = nn.Identity()
+
+    def forward(self, x):
+        return self.norm(self.conv(self.pool(x)))
+
+
+class ConvAttention(nn.Module):
+    """
+    Multi-Head Convolutional Attention
+    """
+
+    def __init__(self, out_chs, head_dim, norm_layer = nn.BatchNorm2d, act_layer = nn.ReLU):
+        super(ConvAttention, self).__init__()
+        self.group_conv3x3 = nn.Conv2d(
+            out_chs, out_chs,
+            kernel_size=3, stride=1, padding=1, groups=out_chs // head_dim, bias=False
+        )
+        self.norm = norm_layer(out_chs)
+        self.act = act_layer()
+        self.projection = nn.Conv2d(out_chs, out_chs, kernel_size=1, bias=False)
+
+    def forward(self, x):
+        out = self.group_conv3x3(x)
+        out = self.norm(out)
+        out = self.act(out)
+        out = self.projection(out)
+        return out
+
+class NextConvBlock(nn.Module):
+    """
+    Next Convolution Block
+    """
+
+    def __init__(
+            self,
+            in_chs,
+            out_chs,
+            stride=1,
+            drop_path=0.,
+            drop=0.,
+            head_dim=32,
+            mlp_ratio=3.,
+            norm_layer=nn.BatchNorm2d,
+            act_layer=nn.ReLU
+    ):
+        super(NextConvBlock, self).__init__()
+        self.in_chs = in_chs
+        self.out_chs = out_chs
+        assert out_chs % head_dim == 0
+
+        self.patch_embed = PatchEmbed(in_chs, out_chs, stride, norm_layer=norm_layer)
+        self.mhca = ConvAttention(
+            out_chs,
+            head_dim,
+            norm_layer=norm_layer,
+            act_layer=act_layer,
+        )
+        self.attn_drop_path = DropPath(drop_path)
+
+        self.norm = norm_layer(out_chs)
+        self.mlp = ConvMlp(
+            out_chs,
+            hidden_features=int(out_chs * mlp_ratio),
+            drop=drop,
+            bias=True,
+            act_layer=act_layer,
+        )
+        self.mlp_drop_path = DropPath(drop_path)
+        self.is_fused = False
+
+    @torch.no_grad()
+    def reparameterize(self):
+        if not self.is_fused:
+            merge_pre_bn(self.mlp.fc1, self.norm)
+            self.norm = None
+            self.is_fused = True
+
+    def forward(self, x):
+        x = self.patch_embed(x)
+        x = x + self.attn_drop_path(self.mhca(x))
+
+        out = self.norm(x)
+        x = x + self.mlp_drop_path(self.mlp(out))
+        return x
+
+
+class EfficientAttention(nn.Module):
+    """
+    Efficient Multi-Head Self Attention
+    """
+    fused_attn: torch.jit.Final[bool]
+
+    def __init__(
+            self,
+            dim,
+            out_dim=None,
+            head_dim=32,
+            qkv_bias=True,
+            attn_drop=0.,
+            proj_drop=0.,
+            sr_ratio=1,
+            norm_layer=nn.BatchNorm1d,
+    ):
+        super().__init__()
+        self.dim = dim
+        self.out_dim = out_dim if out_dim is not None else dim
+        self.num_heads = self.dim // head_dim
+        self.head_dim = head_dim
+        self.scale = head_dim ** -0.5
+        self.fused_attn = use_fused_attn()
+
+        self.q = nn.Linear(dim, self.dim, bias=qkv_bias)
+        self.k = nn.Linear(dim, self.dim, bias=qkv_bias)
+        self.v = nn.Linear(dim, self.dim, bias=qkv_bias)
+        self.proj = nn.Linear(self.dim, self.out_dim)
+        self.attn_drop = nn.Dropout(attn_drop)
+        self.proj_drop = nn.Dropout(proj_drop)
+
+        self.sr_ratio = sr_ratio
+        self.N_ratio = sr_ratio ** 2
+        if sr_ratio > 1:
+            self.sr = nn.AvgPool1d(kernel_size=self.N_ratio, stride=self.N_ratio)
+            self.norm = norm_layer(dim)
+        else:
+            self.sr = None
+            self.norm = None
+
+    def forward(self, x):
+        B, N, C = x.shape
+        q = self.q(x).reshape(B, N, self.num_heads, self.head_dim).permute(0, 2, 1, 3)
+
+        if self.sr is not None:
+            x = self.sr(x.transpose(1, 2))
+            x = self.norm(x).transpose(1, 2)
+
+        k = self.k(x).reshape(B, -1, self.num_heads, self.head_dim).transpose(1, 2)
+        v = self.v(x).reshape(B, -1, self.num_heads, self.head_dim).transpose(1, 2)
+
+        if self.fused_attn:
+            x = F.scaled_dot_product_attention(
+                q, k, v,
+                dropout_p=self.attn_drop.p if self.training else 0.,
+            )
+        else:
+            q = q * self.scale
+            attn = q @ k.transpose(-1, -2)
+            attn = attn.softmax(dim=-1)
+            attn = self.attn_drop(attn)
+            x = attn @ v
+
+        x = x.transpose(1, 2).reshape(B, N, C)
+        x = self.proj(x)
+        x = self.proj_drop(x)
+        return x
+
+
+class NextTransformerBlock(nn.Module):
+    """
+    Next Transformer Block
+    """
+
+    def __init__(
+            self,
+            in_chs,
+            out_chs,
+            drop_path,
+            stride=1,
+            sr_ratio=1,
+            mlp_ratio=2,
+            head_dim=32,
+            mix_block_ratio=0.75,
+            attn_drop=0.,
+            drop=0.,
+            norm_layer=nn.BatchNorm2d,
+            act_layer=nn.ReLU,
+    ):
+        super(NextTransformerBlock, self).__init__()
+        self.in_chs = in_chs
+        self.out_chs = out_chs
+        self.mix_block_ratio = mix_block_ratio
+
+        self.mhsa_out_chs = _make_divisible(int(out_chs * mix_block_ratio), 32)
+        self.mhca_out_chs = out_chs - self.mhsa_out_chs
+
+        self.patch_embed = PatchEmbed(in_chs, self.mhsa_out_chs, stride)
+        self.norm1 = norm_layer(self.mhsa_out_chs)
+        self.e_mhsa = EfficientAttention(
+            self.mhsa_out_chs,
+            head_dim=head_dim,
+            sr_ratio=sr_ratio,
+            attn_drop=attn_drop,
+            proj_drop=drop,
+        )
+        self.mhsa_drop_path = DropPath(drop_path * mix_block_ratio)
+
+        self.projection = PatchEmbed(self.mhsa_out_chs, self.mhca_out_chs, stride=1, norm_layer=norm_layer)
+        self.mhca = ConvAttention(
+            self.mhca_out_chs,
+            head_dim=head_dim,
+            norm_layer=norm_layer,
+            act_layer=act_layer,
+        )
+        self.mhca_drop_path = DropPath(drop_path * (1 - mix_block_ratio))
+
+        self.norm2 = norm_layer(out_chs)
+        self.mlp = ConvMlp(
+            out_chs,
+            hidden_features=int(out_chs * mlp_ratio),
+            act_layer=act_layer,
+            drop=drop,
+        )
+        self.mlp_drop_path = DropPath(drop_path)
+        self.is_fused = False
+
+    @torch.no_grad()
+    def reparameterize(self):
+        if not self.is_fused:
+            merge_pre_bn(self.e_mhsa.q, self.norm1)
+            if self.e_mhsa.norm is not None:
+                merge_pre_bn(self.e_mhsa.k, self.norm1, self.e_mhsa.norm)
+                merge_pre_bn(self.e_mhsa.v, self.norm1, self.e_mhsa.norm)
+                self.e_mhsa.norm = nn.Identity()
+            else:
+                merge_pre_bn(self.e_mhsa.k, self.norm1)
+                merge_pre_bn(self.e_mhsa.v, self.norm1)
+            self.norm1 = nn.Identity()
+
+            merge_pre_bn(self.mlp.fc1, self.norm2)
+            self.norm2 = nn.Identity()
+            self.is_fused = True
+
+    def forward(self, x):
+        x = self.patch_embed(x)
+        B, C, H, W = x.shape
+
+        out = self.norm1(x)
+        out = out.reshape(B, C, -1).transpose(-1, -2)
+        out = self.mhsa_drop_path(self.e_mhsa(out))
+        x = x + out.transpose(-1, -2).reshape(B, C, H, W)
+
+        out = self.projection(x)
+        out = out + self.mhca_drop_path(self.mhca(out))
+        x = torch.cat([x, out], dim=1)
+
+        out = self.norm2(x)
+        x = x + self.mlp_drop_path(self.mlp(out))
+        return x
+
+
+class NextStage(nn.Module):
+
+    def __init__(
+            self,
+            in_chs,
+            block_chs,
+            block_types,
+            stride=2,
+            sr_ratio=1,
+            mix_block_ratio=1.0,
+            drop=0.,
+            attn_drop=0.,
+            drop_path=0.,
+            head_dim=32,
+            norm_layer=nn.BatchNorm2d,
+            act_layer=nn.ReLU,
+    ):
+        super().__init__()
+        self.grad_checkpointing = False
+
+        blocks = []
+        for block_idx, block_type in enumerate(block_types):
+            stride = stride if block_idx == 0 else 1
+            out_chs = block_chs[block_idx]
+            block_type = block_types[block_idx]
+            dpr = drop_path[block_idx] if isinstance(drop_path, (list, tuple)) else drop_path
+            if block_type is NextConvBlock:
+                layer = NextConvBlock(
+                    in_chs,
+                    out_chs,
+                    stride=stride,
+                    drop_path=dpr,
+                    drop=drop,
+                    head_dim=head_dim,
+                    norm_layer=norm_layer,
+                    act_layer=act_layer,
+                )
+                blocks.append(layer)
+            elif block_type is NextTransformerBlock:
+                layer = NextTransformerBlock(
+                    in_chs,
+                    out_chs,
+                    drop_path=dpr,
+                    stride=stride,
+                    sr_ratio=sr_ratio,
+                    head_dim=head_dim,
+                    mix_block_ratio=mix_block_ratio,
+                    attn_drop=attn_drop,
+                    drop=drop,
+                    norm_layer=norm_layer,
+                    act_layer=act_layer,
+                )
+                blocks.append(layer)
+            in_chs = out_chs
+
+        self.blocks = nn.Sequential(*blocks)
+
+    @torch.jit.ignore
+    def set_grad_checkpointing(self, enable=True):
+        self.grad_checkpointing = enable
+
+    def forward(self, x):
+        if self.grad_checkpointing and not torch.jit.is_scripting():
+            x = checkpoint_seq(self.blocks, x)
+        else:
+            x = self.blocks(x)
+        return x
+
+
+class NextViT(nn.Module):
+    def __init__(
+            self,
+            in_chans,
+            num_classes=1000,
+            global_pool='avg',
+            stem_chs=(64, 32, 64),
+            depths=(3, 4, 10, 3),
+            strides=(1, 2, 2, 2),
+            sr_ratios=(8, 4, 2, 1),
+            drop_path_rate=0.1,
+            attn_drop_rate=0.,
+            drop_rate=0.,
+            head_dim=32,
+            mix_block_ratio=0.75,
+            norm_layer=nn.BatchNorm2d,
+            act_layer=None,
+    ):
+        super(NextViT, self).__init__()
+        self.grad_checkpointing = False
+        self.num_classes = num_classes
+        norm_layer = get_norm_layer(norm_layer)
+        if act_layer is None:
+            act_layer = partial(nn.ReLU, inplace=True)
+        else:
+            act_layer = get_act_layer(act_layer)
+
+        self.stage_out_chs = [
+            [96] * (depths[0]),
+            [192] * (depths[1] - 1) + [256],
+            [384, 384, 384, 384, 512] * (depths[2] // 5),
+            [768] * (depths[3] - 1) + [1024]
+        ]
+        self.feature_info = [dict(
+            num_chs=sc[-1],
+            reduction=2**(i + 2),
+            module=f'stages.{i}'
+        ) for i, sc in enumerate(self.stage_out_chs)]
+
+        # Next Hybrid Strategy
+        self.stage_block_types = [
+            [NextConvBlock] * depths[0],
+            [NextConvBlock] * (depths[1] - 1) + [NextTransformerBlock],
+            [NextConvBlock, NextConvBlock, NextConvBlock, NextConvBlock, NextTransformerBlock] * (depths[2] // 5),
+            [NextConvBlock] * (depths[3] - 1) + [NextTransformerBlock]]
+
+        self.stem = nn.Sequential(
+            ConvNormAct(in_chans, stem_chs[0], kernel_size=3, stride=2, norm_layer=norm_layer, act_layer=act_layer),
+            ConvNormAct(stem_chs[0], stem_chs[1], kernel_size=3, stride=1, norm_layer=norm_layer, act_layer=act_layer),
+            ConvNormAct(stem_chs[1], stem_chs[2], kernel_size=3, stride=1, norm_layer=norm_layer, act_layer=act_layer),
+            ConvNormAct(stem_chs[2], stem_chs[2], kernel_size=3, stride=2, norm_layer=norm_layer, act_layer=act_layer),
+        )
+        in_chs = out_chs = stem_chs[-1]
+        stages = []
+        idx = 0
+        dpr = [x.tolist() for x in torch.linspace(0, drop_path_rate, sum(depths)).split(depths)]
+        for stage_idx in range(len(depths)):
+            stage = NextStage(
+                in_chs=in_chs,
+                block_chs=self.stage_out_chs[stage_idx],
+                block_types=self.stage_block_types[stage_idx],
+                stride=strides[stage_idx],
+                sr_ratio=sr_ratios[stage_idx],
+                mix_block_ratio=mix_block_ratio,
+                head_dim=head_dim,
+                drop=drop_rate,
+                attn_drop=attn_drop_rate,
+                drop_path=dpr[stage_idx],
+                norm_layer=norm_layer,
+                act_layer=act_layer,
+            )
+            in_chs = out_chs = self.stage_out_chs[stage_idx][-1]
+            stages += [stage]
+            idx += depths[stage_idx]
+        self.num_features = out_chs
+        self.stages = nn.Sequential(*stages)
+        self.norm = norm_layer(out_chs)
+        self.head = ClassifierHead(pool_type=global_pool, in_features=out_chs, num_classes=num_classes)
+
+        self.stage_out_idx = [sum(depths[:idx + 1]) - 1 for idx in range(len(depths))]
+        self._initialize_weights()
+
+    def _initialize_weights(self):
+        for n, m in self.named_modules():
+            if isinstance(m, nn.Linear):
+                trunc_normal_(m.weight, std=.02)
+                if hasattr(m, 'bias') and m.bias is not None:
+                    nn.init.constant_(m.bias, 0)
+            elif isinstance(m, nn.Conv2d):
+                trunc_normal_(m.weight, std=.02)
+                if hasattr(m, 'bias') and m.bias is not None:
+                    nn.init.constant_(m.bias, 0)
+
+    @torch.jit.ignore
+    def group_matcher(self, coarse=False):
+        return dict(
+            stem=r'^stem',  # stem and embed
+            blocks=r'^stages\.(\d+)' if coarse else [
+                (r'^stages\.(\d+)\.blocks\.(\d+)', None),
+                (r'^norm', (99999,)),
+            ]
+        )
+
+    @torch.jit.ignore
+    def set_grad_checkpointing(self, enable=True):
+        self.grad_checkpointing = enable
+        for stage in self.stages:
+            stage.set_grad_checkpointing(enable=enable)
+
+    @torch.jit.ignore
+    def get_classifier(self):
+        return self.head.fc
+
+    def reset_classifier(self, num_classes, global_pool=None):
+        self.head.reset(num_classes, pool_type=global_pool)
+
+    def forward_features(self, x):
+        x = self.stem(x)
+        if self.grad_checkpointing and not torch.jit.is_scripting():
+            x = checkpoint_seq(self.stages, x)
+        else:
+            x = self.stages(x)
+        x = self.norm(x)
+        return x
+
+    def forward_head(self, x, pre_logits: bool = False):
+        return self.head(x, pre_logits=pre_logits) if pre_logits else self.head(x)
+
+    def forward(self, x):
+        x = self.forward_features(x)
+        x = self.forward_head(x)
+        return x
+
+
+def checkpoint_filter_fn(state_dict, model):
+    """ Remap original checkpoints -> timm """
+    if 'head.fc.weight' in state_dict:
+        return state_dict  # non-original
+
+    D = model.state_dict()
+    out_dict = {}
+    # remap originals based on order
+    for ka, kb, va, vb in zip(D.keys(), state_dict.keys(), D.values(), state_dict.values()):
+        out_dict[ka] = vb
+
+    return out_dict
+
+
+def _create_nextvit(variant, pretrained=False, **kwargs):
+    default_out_indices = tuple(i for i, _ in enumerate(kwargs.get('depths', (1, 1, 3, 1))))
+    out_indices = kwargs.pop('out_indices', default_out_indices)
+
+    model = build_model_with_cfg(
+        NextViT,
+        variant,
+        pretrained,
+        pretrained_filter_fn=checkpoint_filter_fn,
+        feature_cfg=dict(flatten_sequential=True, out_indices=out_indices),
+        **kwargs)
+
+    return model
+
+
+def _cfg(url='', **kwargs):
+    return {
+        'url': url,
+        'num_classes': 1000, 'input_size': (3, 224, 224), 'pool_size': (7, 7),
+        'crop_pct': 0.95, 'interpolation': 'bicubic',
+        'mean': IMAGENET_DEFAULT_MEAN, 'std': IMAGENET_DEFAULT_STD,
+        'first_conv': 'stem.0.conv', 'classifier': 'head.fc',
+        **kwargs
+    }
+
+
+default_cfgs = generate_default_cfgs({
+    'nextvit_small.bd_in1k': _cfg(
+        hf_hub_id='timm/',
+    ),
+    'nextvit_base.bd_in1k': _cfg(
+        hf_hub_id='timm/',
+    ),
+    'nextvit_large.bd_in1k': _cfg(
+        hf_hub_id='timm/',
+    ),
+    'nextvit_small.bd_in1k_384': _cfg(
+        hf_hub_id='timm/',
+        input_size=(3, 384, 384), pool_size=(12, 12), crop_pct=1.0,
+    ),
+    'nextvit_base.bd_in1k_384': _cfg(
+        hf_hub_id='timm/',
+        input_size=(3, 384, 384), pool_size=(12, 12), crop_pct=1.0,
+    ),
+    'nextvit_large.bd_in1k_384': _cfg(
+        hf_hub_id='timm/',
+        input_size=(3, 384, 384), pool_size=(12, 12), crop_pct=1.0,
+    ),
+
+    'nextvit_small.bd_ssld_6m_in1k': _cfg(
+        hf_hub_id='timm/',
+    ),
+    'nextvit_base.bd_ssld_6m_in1k': _cfg(
+        hf_hub_id='timm/',
+    ),
+    'nextvit_large.bd_ssld_6m_in1k': _cfg(
+        hf_hub_id='timm/',
+    ),
+    'nextvit_small.bd_ssld_6m_in1k_384': _cfg(
+        hf_hub_id='timm/',
+        input_size=(3, 384, 384), pool_size=(12, 12), crop_pct=1.0,
+    ),
+    'nextvit_base.bd_ssld_6m_in1k_384': _cfg(
+        hf_hub_id='timm/',
+        input_size=(3, 384, 384), pool_size=(12, 12), crop_pct=1.0,
+    ),
+    'nextvit_large.bd_ssld_6m_in1k_384': _cfg(
+        hf_hub_id='timm/',
+        input_size=(3, 384, 384), pool_size=(12, 12), crop_pct=1.0,
+    ),
+})
+
+
+@register_model
+def nextvit_small(pretrained=False, **kwargs):
+    model_args = dict(depths=(3, 4, 10, 3), drop_path_rate=0.1)
+    model = _create_nextvit(
+        'nextvit_small', pretrained=pretrained, **dict(model_args, **kwargs))
+    return model
+
+
+@register_model
+def nextvit_base(pretrained=False, **kwargs):
+    model_args = dict(depths=(3, 4, 20, 3), drop_path_rate=0.2)
+    model = _create_nextvit(
+        'nextvit_base', pretrained=pretrained, **dict(model_args, **kwargs))
+    return model
+
+
+@register_model
+def nextvit_large(pretrained=False, **kwargs):
+    model_args = dict(depths=(3, 4, 30, 3), drop_path_rate=0.2)
+    model = _create_nextvit(
+        'nextvit_large', pretrained=pretrained, **dict(model_args, **kwargs))
+    return model

timm/models/tiny_vit.py

@@ -535,7 +535,7 @@ class TinyVit(nn.Module):
 
     def reset_classifier(self, num_classes, global_pool=None):
         self.num_classes = num_classes
-        self.head.reset(num_classes, global_pool=global_pool)
+        self.head.reset(num_classes, pool_type=global_pool)
 
     def forward_features(self, x):
         x = self.patch_embed(x)

timm/models/vision_transformer.py

@@ -421,6 +421,7 @@ class VisionTransformer(nn.Module):
             attn_drop_rate: float = 0.,
             drop_path_rate: float = 0.,
             weight_init: Literal['skip', 'jax', 'jax_nlhb', 'moco', ''] = '',
+            fix_init: bool = False,
             embed_layer: Callable = PatchEmbed,
             norm_layer: Optional[LayerType] = None,
             act_layer: Optional[LayerType] = None,
@@ -449,6 +450,7 @@ class VisionTransformer(nn.Module):
             attn_drop_rate: Attention dropout rate.
             drop_path_rate: Stochastic depth rate.
             weight_init: Weight initialization scheme.
+            fix_init: Apply weight initialization fix (scaling w/ layer index).
             embed_layer: Patch embedding layer.
             norm_layer: Normalization layer.
             act_layer: MLP activation layer.
@@ -536,8 +538,18 @@ class VisionTransformer(nn.Module):
 
         if weight_init != 'skip':
             self.init_weights(weight_init)
+        if fix_init:
+            self.fix_init_weight()
 
-    def init_weights(self, mode: Literal['jax', 'jax_nlhb', 'moco', ''] = '') -> None:
+    def fix_init_weight(self):
+        def rescale(param, _layer_id):
+            param.div_(math.sqrt(2.0 * _layer_id))
+
+        for layer_id, layer in enumerate(self.blocks):
+            rescale(layer.attn.proj.weight.data, layer_id + 1)
+            rescale(layer.mlp.fc2.weight.data, layer_id + 1)
+
+    def init_weights(self, mode: str = '') -> None:
         assert mode in ('jax', 'jax_nlhb', 'moco', '')
         head_bias = -math.log(self.num_classes) if 'nlhb' in mode else 0.
         trunc_normal_(self.pos_embed, std=.02)
@@ -737,7 +749,7 @@ def init_weights_vit_moco(module: nn.Module, name: str = '') -> None:
         module.init_weights()
 
 
-def get_init_weights_vit(mode: str = 'jax', head_bias: float = 0.0) -> None:
+def get_init_weights_vit(mode: str = 'jax', head_bias: float = 0.0) -> Callable:
     if 'jax' in mode:
         return partial(init_weights_vit_jax, head_bias=head_bias)
     elif 'moco' in mode:
@@ -1723,7 +1735,12 @@ default_cfgs = {
         input_size=(3, 256, 256)),
     'vit_medium_patch16_reg4_gap_256': _cfg(
         input_size=(3, 256, 256)),
-    'vit_base_patch16_reg8_gap_256': _cfg(input_size=(3, 256, 256)),
+    'vit_base_patch16_reg4_gap_256': _cfg(
+        input_size=(3, 256, 256)),
+    'vit_so150m_patch16_reg4_gap_256': _cfg(
+        input_size=(3, 256, 256)),
+    'vit_so150m_patch16_reg4_map_256': _cfg(
+        input_size=(3, 256, 256)),
 }
 
 _quick_gelu_cfgs = [
@@ -2623,13 +2640,35 @@ def vit_medium_patch16_reg4_gap_256(pretrained: bool = False, **kwargs) -> Visio
 
 
 @register_model
-def vit_base_patch16_reg8_gap_256(pretrained: bool = False, **kwargs) -> VisionTransformer:
+def vit_base_patch16_reg4_gap_256(pretrained: bool = False, **kwargs) -> VisionTransformer:
     model_args = dict(
         patch_size=16, embed_dim=768, depth=12, num_heads=12, class_token=False,
-        no_embed_class=True, global_pool='avg', reg_tokens=8,
+        no_embed_class=True, global_pool='avg', reg_tokens=4,
     )
     model = _create_vision_transformer(
-        'vit_base_patch16_reg8_gap_256', pretrained=pretrained, **dict(model_args, **kwargs))
+        'vit_base_patch16_reg4_gap_256', pretrained=pretrained, **dict(model_args, **kwargs))
+    return model
+
+
+@register_model
+def vit_so150m_patch16_reg4_map_256(pretrained: bool = False, **kwargs) -> VisionTransformer:
+    model_args = dict(
+        patch_size=16, embed_dim=896, depth=18, num_heads=14, mlp_ratio=2.572,
+        class_token=False, reg_tokens=4, global_pool='map',
+    )
+    model = _create_vision_transformer(
+        'vit_so150m_patch16_reg4_map_256', pretrained=pretrained, **dict(model_args, **kwargs))
+    return model
+
+
+@register_model
+def vit_so150m_patch16_reg4_gap_256(pretrained: bool = False, **kwargs) -> VisionTransformer:
+    model_args = dict(
+        patch_size=16, embed_dim=896, depth=18, num_heads=14, mlp_ratio=2.572,
+        class_token=False, reg_tokens=4, global_pool='avg', fc_norm=False,
+    )
+    model = _create_vision_transformer(
+        'vit_so150m_patch16_reg4_gap_256', pretrained=pretrained, **dict(model_args, **kwargs))
     return model
 
 

timm/models/vision_transformer_relpos.py

@@ -7,7 +7,12 @@ Hacked together by / Copyright 2022, Ross Wightman
 import logging
 import math
 from functools import partial
-from typing import Optional, Tuple
+from typing import Optional, Tuple, Type, Union
+
+try:
+    from typing import Literal
+except ImportError:
+    from typing_extensions import Literal
 
 import torch
 import torch.nn as nn
@@ -15,9 +20,11 @@ from torch.jit import Final
 from torch.utils.checkpoint import checkpoint
 
 from timm.data import IMAGENET_INCEPTION_MEAN, IMAGENET_INCEPTION_STD
-from timm.layers import PatchEmbed, Mlp, DropPath, RelPosMlp, RelPosBias, use_fused_attn
+from timm.layers import PatchEmbed, Mlp, DropPath, RelPosMlp, RelPosBias, use_fused_attn, LayerType
 from ._builder import build_model_with_cfg
+from ._manipulate import named_apply
 from ._registry import generate_default_cfgs, register_model
+from .vision_transformer import get_init_weights_vit
 
 __all__ = ['VisionTransformerRelPos']  # model_registry will add each entrypoint fn to this
 
@@ -215,59 +222,61 @@ class VisionTransformerRelPos(nn.Module):
 
     def __init__(
             self,
-            img_size=224,
+            img_size: Union[int, Tuple[int, int]] = 224,
-            patch_size=16,
+            patch_size: Union[int, Tuple[int, int]] = 16,
-            in_chans=3,
+            in_chans: int = 3,
-            num_classes=1000,
+            num_classes: int = 1000,
-            global_pool='avg',
+            global_pool: Literal['', 'avg', 'token', 'map'] = 'avg',
-            embed_dim=768,
+            embed_dim: int = 768,
-            depth=12,
+            depth: int = 12,
-            num_heads=12,
+            num_heads: int = 12,
-            mlp_ratio=4.,
+            mlp_ratio: float = 4.,
-            qkv_bias=True,
+            qkv_bias: bool = True,
-            qk_norm=False,
+            qk_norm: bool = False,
-            init_values=1e-6,
+            init_values: Optional[float] = 1e-6,
-            class_token=False,
+            class_token: bool = False,
-            fc_norm=False,
+            fc_norm: bool = False,
-            rel_pos_type='mlp',
+            rel_pos_type: str = 'mlp',
-            rel_pos_dim=None,
+            rel_pos_dim: Optional[int] = None,
-            shared_rel_pos=False,
+            shared_rel_pos: bool = False,
-            drop_rate=0.,
+            drop_rate: float = 0.,
-            proj_drop_rate=0.,
+            proj_drop_rate: float = 0.,
-            attn_drop_rate=0.,
+            attn_drop_rate: float = 0.,
-            drop_path_rate=0.,
+            drop_path_rate: float = 0.,
-            weight_init='skip',
+            weight_init: Literal['skip', 'jax', 'moco', ''] = 'skip',
-            embed_layer=PatchEmbed,
+            fix_init: bool = False,
-            norm_layer=None,
+            embed_layer: Type[nn.Module] = PatchEmbed,
-            act_layer=None,
+            norm_layer: Optional[LayerType] = None,
-            block_fn=RelPosBlock
+            act_layer: Optional[LayerType] = None,
+            block_fn: Type[nn.Module] = RelPosBlock
     ):
         """
         Args:
-            img_size (int, tuple): input image size
+            img_size: input image size
-            patch_size (int, tuple): patch size
+            patch_size: patch size
-            in_chans (int): number of input channels
+            in_chans: number of input channels
-            num_classes (int): number of classes for classification head
+            num_classes: number of classes for classification head
-            global_pool (str): type of global pooling for final sequence (default: 'avg')
+            global_pool: type of global pooling for final sequence (default: 'avg')
-            embed_dim (int): embedding dimension
+            embed_dim: embedding dimension
-            depth (int): depth of transformer
+            depth: depth of transformer
-            num_heads (int): number of attention heads
+            num_heads: number of attention heads
-            mlp_ratio (int): ratio of mlp hidden dim to embedding dim
+            mlp_ratio: ratio of mlp hidden dim to embedding dim
-            qkv_bias (bool): enable bias for qkv if True
+            qkv_bias: enable bias for qkv if True
-            qk_norm (bool): Enable normalization of query and key in attention
+            qk_norm: Enable normalization of query and key in attention
-            init_values: (float): layer-scale init values
+            init_values: layer-scale init values
-            class_token (bool): use class token (default: False)
+            class_token: use class token (default: False)
-            fc_norm (bool): use pre classifier norm instead of pre-pool
+            fc_norm: use pre classifier norm instead of pre-pool
-            rel_pos_ty pe (str): type of relative position
+            rel_pos_type: type of relative position
-            shared_rel_pos (bool): share relative pos across all blocks
+            shared_rel_pos: share relative pos across all blocks
-            drop_rate (float): dropout rate
+            drop_rate: dropout rate
-            proj_drop_rate (float): projection dropout rate
+            proj_drop_rate: projection dropout rate
-            attn_drop_rate (float): attention dropout rate
+            attn_drop_rate: attention dropout rate
-            drop_path_rate (float): stochastic depth rate
+            drop_path_rate: stochastic depth rate
-            weight_init (str): weight init scheme
+            weight_init: weight init scheme
-            embed_layer (nn.Module): patch embedding layer
+            fix_init: apply weight initialization fix (scaling w/ layer index)
-            norm_layer: (nn.Module): normalization layer
+            embed_layer: patch embedding layer
-            act_layer: (nn.Module): MLP activation layer
+            norm_layer: normalization layer
+            act_layer: MLP activation layer
         """
         super().__init__()
         assert global_pool in ('', 'avg', 'token')
@@ -332,13 +341,22 @@ class VisionTransformerRelPos(nn.Module):
 
         if weight_init != 'skip':
             self.init_weights(weight_init)
+        if fix_init:
+            self.fix_init_weight()
 
     def init_weights(self, mode=''):
         assert mode in ('jax', 'moco', '')
         if self.cls_token is not None:
             nn.init.normal_(self.cls_token, std=1e-6)
-        # FIXME weight init scheme using PyTorch defaults curently
+        named_apply(get_init_weights_vit(mode), self)
-        #named_apply(get_init_weights_vit(mode, head_bias), self)
+
+    def fix_init_weight(self):
+        def rescale(param, _layer_id):
+            param.div_(math.sqrt(2.0 * _layer_id))
+
+        for layer_id, layer in enumerate(self.blocks):
+            rescale(layer.attn.proj.weight.data, layer_id + 1)
+            rescale(layer.mlp.fc2.weight.data, layer_id + 1)
 
     @torch.jit.ignore
     def no_weight_decay(self):

timm/utils/__init__.py

@@ -10,6 +10,6 @@ from .log import setup_default_logging, FormatterNoInfo
 from .metrics import AverageMeter, accuracy
 from .misc import natural_key, add_bool_arg, ParseKwargs
 from .model import unwrap_model, get_state_dict, freeze, unfreeze, reparameterize_model
-from .model_ema import ModelEma, ModelEmaV2
+from .model_ema import ModelEma, ModelEmaV2, ModelEmaV3
 from .random import random_seed
 from .summary import update_summary, get_outdir

timm/utils/distributed.py

@@ -2,18 +2,17 @@
 
 Hacked together by / Copyright 2020 Ross Wightman
 """
+import logging
 import os
+from typing import Optional
 
 import torch
 from torch import distributed as dist
 
-try:
-    import horovod.torch as hvd
-except ImportError:
-    hvd = None
-
 from .model import unwrap_model
 
+_logger = logging.getLogger(__name__)
+
 
 def reduce_tensor(tensor, n):
     rt = tensor.clone()
@@ -84,9 +83,39 @@ def init_distributed_device(args):
     args.world_size = 1
     args.rank = 0  # global rank
     args.local_rank = 0
+    result = init_distributed_device_so(
+        device=getattr(args, 'device', 'cuda'),
+        dist_backend=getattr(args, 'dist_backend', None),
+        dist_url=getattr(args, 'dist_url', None),
+    )
+    args.device = result['device']
+    args.world_size = result['world_size']
+    args.rank = result['global_rank']
+    args.local_rank = result['local_rank']
+    args.distributed = result['distributed']
+    device = torch.device(args.device)
+    return device
+
+
+def init_distributed_device_so(
+        device: str = 'cuda',
+        dist_backend: Optional[str] = None,
+        dist_url: Optional[str] = None,
+):
+    # Distributed training = training on more than one GPU.
+    # Works in both single and multi-node scenarios.
+    distributed = False
+    world_size = 1
+    global_rank = 0
+    local_rank = 0
+    if dist_backend is None:
+        # FIXME sane defaults for other device backends?
+        dist_backend = 'nccl' if 'cuda' in device else 'gloo'
+    dist_url = dist_url or 'env://'
 
     # TBD, support horovod?
     # if args.horovod:
+    #     import horovod.torch as hvd
     #     assert hvd is not None, "Horovod is not installed"
     #     hvd.init()
     #     args.local_rank = int(hvd.local_rank())
@@ -96,42 +125,51 @@ def init_distributed_device(args):
     #     os.environ['LOCAL_RANK'] = str(args.local_rank)
     #     os.environ['RANK'] = str(args.rank)
     #     os.environ['WORLD_SIZE'] = str(args.world_size)
-    dist_backend = getattr(args, 'dist_backend', 'nccl')
-    dist_url = getattr(args, 'dist_url', 'env://')
     if is_distributed_env():
         if 'SLURM_PROCID' in os.environ:
             # DDP via SLURM
-            args.local_rank, args.rank, args.world_size = world_info_from_env()
+            local_rank, global_rank, world_size = world_info_from_env()
             # SLURM var -> torch.distributed vars in case needed
-            os.environ['LOCAL_RANK'] = str(args.local_rank)
+            os.environ['LOCAL_RANK'] = str(local_rank)
-            os.environ['RANK'] = str(args.rank)
+            os.environ['RANK'] = str(global_rank)
-            os.environ['WORLD_SIZE'] = str(args.world_size)
+            os.environ['WORLD_SIZE'] = str(world_size)
             torch.distributed.init_process_group(
                 backend=dist_backend,
                 init_method=dist_url,
-                world_size=args.world_size,
+                world_size=world_size,
-                rank=args.rank,
+                rank=global_rank,
             )
         else:
             # DDP via torchrun, torch.distributed.launch
-            args.local_rank, _, _ = world_info_from_env()
+            local_rank, _, _ = world_info_from_env()
             torch.distributed.init_process_group(
                 backend=dist_backend,
                 init_method=dist_url,
             )
-            args.world_size = torch.distributed.get_world_size()
+            world_size = torch.distributed.get_world_size()
-            args.rank = torch.distributed.get_rank()
+            global_rank = torch.distributed.get_rank()
-        args.distributed = True
+        distributed = True
 
-    if torch.cuda.is_available():
+    if 'cuda' in device:
-        if args.distributed:
+        assert torch.cuda.is_available(), f'CUDA is not available but {device} was specified.'
-            device = 'cuda:%d' % args.local_rank
+
-        else:
+    if distributed and device != 'cpu':
-            device = 'cuda:0'
+        device, *device_idx = device.split(':', maxsplit=1)
+
+        # Ignore manually specified device index in distributed mode and
+        # override with resolved local rank, fewer headaches in most setups.
+        if device_idx:
+            _logger.warning(f'device index {device_idx[0]} removed from specified ({device}).')
+
+        device = f'{device}:{local_rank}'
+
+    if device.startswith('cuda:'):
         torch.cuda.set_device(device)
-    else:
-        device = 'cpu'
 
-    args.device = device
+    return dict(
-    device = torch.device(device)
+        device=device,
-    return device
+        global_rank=global_rank,
+        local_rank=local_rank,
+        world_size=world_size,
+        distributed=distributed,
+    )

timm/utils/model_ema.py

@@ -5,6 +5,7 @@ Hacked together by / Copyright 2020 Ross Wightman
 import logging
 from collections import OrderedDict
 from copy import deepcopy
+from typing import Optional
 
 import torch
 import torch.nn as nn
@@ -103,7 +104,7 @@ class ModelEmaV2(nn.Module):
     GPU assignment and distributed training wrappers.
     """
     def __init__(self, model, decay=0.9999, device=None):
-        super(ModelEmaV2, self).__init__()
+        super().__init__()
         # make a copy of the model for accumulating moving average of weights
         self.module = deepcopy(model)
         self.module.eval()
@@ -124,3 +125,136 @@ class ModelEmaV2(nn.Module):
 
     def set(self, model):
         self._update(model, update_fn=lambda e, m: m)
+
+    def forward(self, *args, **kwargs):
+        return self.module(*args, **kwargs)
+
+
+class ModelEmaV3(nn.Module):
+    """ Model Exponential Moving Average V3
+
+    Keep a moving average of everything in the model state_dict (parameters and buffers).
+    V3 of this module leverages for_each and in-place operations for faster performance.
+
+    Decay warmup based on code by @crowsonkb, her comments:
+      If inv_gamma=1 and power=1, implements a simple average. inv_gamma=1, power=2/3 are
+      good values for models you plan to train for a million or more steps (reaches decay
+      factor 0.999 at 31.6K steps, 0.9999 at 1M steps), inv_gamma=1, power=3/4 for models
+      you plan to train for less (reaches decay factor 0.999 at 10K steps, 0.9999 at
+      215.4k steps).
+
+    This is intended to allow functionality like
+    https://www.tensorflow.org/api_docs/python/tf/train/ExponentialMovingAverage
+
+    To keep EMA from using GPU resources, set device='cpu'. This will save a bit of memory but
+    disable validation of the EMA weights. Validation will have to be done manually in a separate
+    process, or after the training stops converging.
+
+    This class is sensitive where it is initialized in the sequence of model init,
+    GPU assignment and distributed training wrappers.
+    """
+    def __init__(
+            self,
+            model,
+            decay: float = 0.9999,
+            min_decay: float = 0.0,
+            update_after_step: int = 0,
+            use_warmup: bool = False,
+            warmup_gamma: float = 1.0,
+            warmup_power: float = 2/3,
+            device: Optional[torch.device] = None,
+            foreach: bool = True,
+            exclude_buffers: bool = False,
+    ):
+        super().__init__()
+        # make a copy of the model for accumulating moving average of weights
+        self.module = deepcopy(model)
+        self.module.eval()
+        self.decay = decay
+        self.min_decay = min_decay
+        self.update_after_step = update_after_step
+        self.use_warmup = use_warmup
+        self.warmup_gamma = warmup_gamma
+        self.warmup_power = warmup_power
+        self.foreach = foreach
+        self.device = device  # perform ema on different device from model if set
+        self.exclude_buffers = exclude_buffers
+        if self.device is not None and device != next(model.parameters()).device:
+            self.foreach = False  # cannot use foreach methods with different devices
+            self.module.to(device=device)
+
+    def get_decay(self, step: Optional[int] = None) -> float:
+        """
+        Compute the decay factor for the exponential moving average.
+        """
+        if step is None:
+            return self.decay
+
+        step = max(0, step - self.update_after_step - 1)
+        if step <= 0:
+            return 0.0
+
+        if self.use_warmup:
+            decay = 1 - (1 + step / self.warmup_gamma) ** -self.warmup_power
+            decay = max(min(decay, self.decay), self.min_decay)
+        else:
+            decay = self.decay
+
+        return decay
+
+    @torch.no_grad()
+    def update(self, model, step: Optional[int] = None):
+        decay = self.get_decay(step)
+        if self.exclude_buffers:
+            self.apply_update_no_buffers_(model, decay)
+        else:
+            self.apply_update_(model, decay)
+
+    def apply_update_(self, model, decay: float):
+        # interpolate parameters and buffers
+        if self.foreach:
+            ema_lerp_values = []
+            model_lerp_values = []
+            for ema_v, model_v in zip(self.module.state_dict().values(), model.state_dict().values()):
+                if ema_v.is_floating_point():
+                    ema_lerp_values.append(ema_v)
+                    model_lerp_values.append(model_v)
+                else:
+                    ema_v.copy_(model_v)
+
+            if hasattr(torch, '_foreach_lerp_'):
+                torch._foreach_lerp_(ema_lerp_values, model_lerp_values, weight=1. - decay)
+            else:
+                torch._foreach_mul_(ema_lerp_values, scalar=decay)
+                torch._foreach_add_(ema_lerp_values, model_lerp_values, alpha=1. - decay)
+        else:
+            for ema_v, model_v in zip(self.module.state_dict().values(), model.state_dict().values()):
+                if ema_v.is_floating_point():
+                    ema_v.lerp_(model_v, weight=1. - decay)
+                else:
+                    ema_v.copy_(model_v)
+
+    def apply_update_no_buffers_(self, model, decay: float):
+        # interpolate parameters, copy buffers
+        ema_params = tuple(self.module.parameters())
+        model_params = tuple(model.parameters())
+        if self.foreach:
+            if hasattr(torch, '_foreach_lerp_'):
+                torch._foreach_lerp_(ema_params, model_params, weight=1. - decay)
+            else:
+                torch._foreach_mul_(ema_params, scalar=decay)
+                torch._foreach_add_(ema_params, model_params, alpha=1 - decay)
+        else:
+            for ema_p, model_p in zip(ema_params, model_params):
+                ema_p.lerp_(model_p, weight=1. - decay)
+
+        for ema_b, model_b in zip(self.module.buffers(), model.buffers()):
+            ema_b.copy_(model_b.to(device=self.device))
+
+    @torch.no_grad()
+    def set(self, model):
+        for ema_v, model_v in zip(self.module.state_dict().values(), model.state_dict().values()):
+            ema_v.copy_(model_v.to(device=self.device))
+
+    def forward(self, *args, **kwargs):
+        return self.module(*args, **kwargs)

train.py

@@ -15,6 +15,7 @@ NVIDIA CUDA specific speedups adopted from NVIDIA Apex examples
 Hacked together by / Copyright 2020 Ross Wightman (https://github.com/rwightman)
 """
 import argparse
+import importlib
 import json
 import logging
 import os
@@ -168,6 +169,24 @@ scripting_group.add_argument('--torchscript', dest='torchscript', action='store_
 scripting_group.add_argument('--torchcompile', nargs='?', type=str, default=None, const='inductor',
                              help="Enable compilation w/ specified backend (default: inductor).")
 
+# Device & distributed
+group = parser.add_argument_group('Device parameters')
+group.add_argument('--device', default='cuda', type=str,
+                    help="Device (accelerator) to use.")
+group.add_argument('--amp', action='store_true', default=False,
+                   help='use NVIDIA Apex AMP or Native AMP for mixed precision training')
+group.add_argument('--amp-dtype', default='float16', type=str,
+                   help='lower precision AMP dtype (default: float16)')
+group.add_argument('--amp-impl', default='native', type=str,
+                   help='AMP impl to use, "native" or "apex" (default: native)')
+group.add_argument('--no-ddp-bb', action='store_true', default=False,
+                   help='Force broadcast buffers for native DDP to off.')
+group.add_argument('--synchronize-step', action='store_true', default=False,
+                   help='torch.cuda.synchronize() end of each step')
+group.add_argument("--local_rank", default=0, type=int)
+parser.add_argument('--device-modules', default=None, type=str, nargs='+',
+                    help="Python imports for device backend modules.")
+
 # Optimizer parameters
 group = parser.add_argument_group('Optimizer parameters')
 group.add_argument('--opt', default='sgd', type=str, metavar='OPTIMIZER',
@@ -330,11 +349,13 @@ group.add_argument('--split-bn', action='store_true',
 # Model Exponential Moving Average
 group = parser.add_argument_group('Model exponential moving average parameters')
 group.add_argument('--model-ema', action='store_true', default=False,
-                   help='Enable tracking moving average of model weights')
+                   help='Enable tracking moving average of model weights.')
 group.add_argument('--model-ema-force-cpu', action='store_true', default=False,
                    help='Force ema to be tracked on CPU, rank=0 node only. Disables EMA validation.')
 group.add_argument('--model-ema-decay', type=float, default=0.9998,
-                   help='decay factor for model weights moving average (default: 0.9998)')
+                   help='Decay factor for model weights moving average (default: 0.9998)')
+group.add_argument('--model-ema-warmup', action='store_true',
+                   help='Enable warmup for model EMA decay.')
 
 # Misc
 group = parser.add_argument_group('Miscellaneous parameters')
@@ -352,16 +373,6 @@ group.add_argument('-j', '--workers', type=int, default=4, metavar='N',
                    help='how many training processes to use (default: 4)')
 group.add_argument('--save-images', action='store_true', default=False,
                    help='save images of input bathes every log interval for debugging')
-group.add_argument('--amp', action='store_true', default=False,
-                   help='use NVIDIA Apex AMP or Native AMP for mixed precision training')
-group.add_argument('--amp-dtype', default='float16', type=str,
-                   help='lower precision AMP dtype (default: float16)')
-group.add_argument('--amp-impl', default='native', type=str,
-                   help='AMP impl to use, "native" or "apex" (default: native)')
-group.add_argument('--no-ddp-bb', action='store_true', default=False,
-                   help='Force broadcast buffers for native DDP to off.')
-group.add_argument('--synchronize-step', action='store_true', default=False,
-                   help='torch.cuda.synchronize() end of each step')
 group.add_argument('--pin-mem', action='store_true', default=False,
                    help='Pin CPU memory in DataLoader for more efficient (sometimes) transfer to GPU.')
 group.add_argument('--no-prefetcher', action='store_true', default=False,
@@ -374,7 +385,6 @@ group.add_argument('--eval-metric', default='top1', type=str, metavar='EVAL_METR
                    help='Best metric (default: "top1"')
 group.add_argument('--tta', type=int, default=0, metavar='N',
                    help='Test/inference time augmentation (oversampling) factor. 0=None (default: 0)')
-group.add_argument("--local_rank", default=0, type=int)
 group.add_argument('--use-multi-epochs-loader', action='store_true', default=False,
                    help='use the multi-epochs-loader to save time at the beginning of every epoch')
 group.add_argument('--log-wandb', action='store_true', default=False,
@@ -402,6 +412,10 @@ def main():
     utils.setup_default_logging()
     args, args_text = _parse_args()
 
+    if args.device_modules:
+        for module in args.device_modules:
+            importlib.import_module(module)
+
     if torch.cuda.is_available():
         torch.backends.cuda.matmul.allow_tf32 = True
         torch.backends.cudnn.benchmark = True
@@ -586,10 +600,16 @@ def main():
     model_ema = None
     if args.model_ema:
         # Important to create EMA model after cuda(), DP wrapper, and AMP but before DDP wrapper
-        model_ema = utils.ModelEmaV2(
+        model_ema = utils.ModelEmaV3(
-            model, decay=args.model_ema_decay, device='cpu' if args.model_ema_force_cpu else None)
+            model,
+            decay=args.model_ema_decay,
+            use_warmup=args.model_ema_warmup,
+            device='cpu' if args.model_ema_force_cpu else None,
+        )
         if args.resume:
             load_checkpoint(model_ema.module, args.resume, use_ema=True)
+        if args.torchcompile:
+            model_ema = torch.compile(model_ema, backend=args.torchcompile)
 
     # setup distributed training
     if args.distributed:
@@ -847,6 +867,7 @@ def main():
                 loss_scaler=loss_scaler,
                 model_ema=model_ema,
                 mixup_fn=mixup_fn,
+                num_updates_total=num_epochs * updates_per_epoch,
             )
 
             if args.distributed and args.dist_bn in ('broadcast', 'reduce'):
@@ -860,6 +881,7 @@ def main():
                     loader_eval,
                     validate_loss_fn,
                     args,
+                    device=device,
                     amp_autocast=amp_autocast,
                 )
 
@@ -868,10 +890,11 @@ def main():
                         utils.distribute_bn(model_ema, args.world_size, args.dist_bn == 'reduce')
 
                     ema_eval_metrics = validate(
-                        model_ema.module,
+                        model_ema,
                         loader_eval,
                         validate_loss_fn,
                         args,
+                        device=device,
                         amp_autocast=amp_autocast,
                         log_suffix=' (EMA)',
                     )
@@ -935,6 +958,7 @@ def train_one_epoch(
         loss_scaler=None,
         model_ema=None,
         mixup_fn=None,
+        num_updates_total=None,
 ):
     if args.mixup_off_epoch and epoch >= args.mixup_off_epoch:
         if args.prefetcher and loader.mixup_enabled:
@@ -1026,7 +1050,7 @@ def train_one_epoch(
         num_updates += 1
         optimizer.zero_grad()
         if model_ema is not None:
-            model_ema.update(model)
+            model_ema.update(model, step=num_updates)
 
         if args.synchronize_step and device.type == 'cuda':
             torch.cuda.synchronize()