Merge remote-tracking branch 'origin/master' into bits_and_tpu

.github/ISSUE_TEMPLATE/config.yml

@@ -2,4 +2,4 @@ blank_issues_enabled: false
 contact_links:
   - name: Community Discussions
     url: https://github.com/rwightman/pytorch-image-models/discussions
-    about: Issues are for features and bugs. Questions can be asked in Discussions.
+    about: Hparam request in issues will be ignored! Issues are for features and bugs. Questions can be asked in Discussions.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,8 +1,7 @@
 ---
 name: Feature request
-about: Suggest an idea for this project. Issues are for reporting bugs or requesting
+about: Suggest an idea for this project. Hparam requests, training help are not feature requests.
-  features, the discussion forum is available for asking questions or seeking help
+  The discussion forum is available for asking questions or seeking help from the community.
-  from the community.
 title: "[FEATURE] Feature title..."
 labels: enhancement
 assignees: ''

README.md

@@ -21,6 +21,30 @@ And a big thanks to all GitHub sponsors who helped with some of my costs before
 
 ## What's New
 
+### Aug 29, 2022
+* MaxVit window size scales with img_size by default. Add new RelPosMlp MaxViT weight that leverages this:
+  * `maxvit_rmlp_nano_rw_256` - 83.0 @ 256, 83.6 @ 320  (T)
+
+### Aug 26, 2022
+* CoAtNet (https://arxiv.org/abs/2106.04803) and MaxVit (https://arxiv.org/abs/2204.01697) `timm` original models
+  * both found in [`maxxvit.py`](https://github.com/rwightman/pytorch-image-models/blob/master/timm/models/maxxvit.py) model def, contains numerous experiments outside scope of original papers
+  * an unfinished Tensorflow version from MaxVit authors can be found https://github.com/google-research/maxvit
+* Initial CoAtNet and MaxVit timm pretrained weights (working on more):
+  * `coatnet_nano_rw_224` - 81.7 @ 224  (T)
+  * `coatnet_rmlp_nano_rw_224` - 82.0 @ 224, 82.8 @ 320 (T)
+  * `coatnet_0_rw_224` - 82.4  (T)  -- NOTE timm '0' coatnets have 2 more 3rd stage blocks
+  * `coatnet_bn_0_rw_224` - 82.4  (T)
+  * `maxvit_nano_rw_256` - 82.9 @ 256  (T)
+  * `coatnet_rmlp_1_rw_224` - 83.4 @ 224, 84 @ 320  (T)
+  * `coatnet_1_rw_224` - 83.6 @ 224 (G) 
+  * (T) = TPU trained with `bits_and_tpu` branch training code, (G) = GPU trained
+* GCVit (weights adapted from https://github.com/NVlabs/GCVit, code 100% `timm` re-write for license purposes)
+* MViT-V2 (multi-scale vit, adapted from https://github.com/facebookresearch/mvit)
+* EfficientFormer (adapted from https://github.com/snap-research/EfficientFormer)
+* PyramidVisionTransformer-V2 (adapted from https://github.com/whai362/PVT)
+* 'Fast Norm' support for LayerNorm and GroupNorm that avoids float32 upcast w/ AMP (uses APEX LN if available for further boost)
+
+
 ### Aug 15, 2022
 * ConvNeXt atto weights added
   * `convnext_atto` - 75.7 @ 224, 77.0 @ 288
@@ -229,6 +253,7 @@ A full version of the list below with source links can be found in the [document
 * Bottleneck Transformers - https://arxiv.org/abs/2101.11605
 * CaiT (Class-Attention in Image Transformers) - https://arxiv.org/abs/2103.17239
 * CoaT (Co-Scale Conv-Attentional Image Transformers) - https://arxiv.org/abs/2104.06399
+* CoAtNet (Convolution and Attention) - https://arxiv.org/abs/2106.04803
 * ConvNeXt - https://arxiv.org/abs/2201.03545
 * ConViT (Soft Convolutional Inductive Biases Vision Transformers)- https://arxiv.org/abs/2103.10697
 * CspNet (Cross-Stage Partial Networks) - https://arxiv.org/abs/1911.11929
@@ -238,6 +263,7 @@ A full version of the list below with source links can be found in the [document
 * DLA - https://arxiv.org/abs/1707.06484
 * DPN (Dual-Path Network) - https://arxiv.org/abs/1707.01629
 * EdgeNeXt - https://arxiv.org/abs/2206.10589
+* EfficientFormer - https://arxiv.org/abs/2206.01191
 * EfficientNet (MBConvNet Family)
     * EfficientNet NoisyStudent (B0-B7, L2) - https://arxiv.org/abs/1911.04252
     * EfficientNet AdvProp (B0-B8) - https://arxiv.org/abs/1911.09665
@@ -250,6 +276,7 @@ A full version of the list below with source links can be found in the [document
     * MobileNet-V2 - https://arxiv.org/abs/1801.04381
     * Single-Path NAS - https://arxiv.org/abs/1904.02877
     * TinyNet - https://arxiv.org/abs/2010.14819
+* GCViT (Global Context Vision Transformer) - https://arxiv.org/abs/2206.09959
 * GhostNet - https://arxiv.org/abs/1911.11907
 * gMLP - https://arxiv.org/abs/2105.08050
 * GPU-Efficient Networks - https://arxiv.org/abs/2006.14090
@@ -259,6 +286,7 @@ A full version of the list below with source links can be found in the [document
 * Inception-ResNet-V2 and Inception-V4 - https://arxiv.org/abs/1602.07261
 * Lambda Networks - https://arxiv.org/abs/2102.08602
 * LeViT (Vision Transformer in ConvNet's Clothing) - https://arxiv.org/abs/2104.01136
+* MaxViT (Multi-Axis Vision Transformer) - https://arxiv.org/abs/2204.01697
 * MLP-Mixer - https://arxiv.org/abs/2105.01601
 * MobileNet-V3 (MBConvNet w/ Efficient Head) - https://arxiv.org/abs/1905.02244
   * FBNet-V3 - https://arxiv.org/abs/2006.02049
@@ -266,6 +294,7 @@ A full version of the list below with source links can be found in the [document
   * LCNet - https://arxiv.org/abs/2109.15099
 * MobileViT - https://arxiv.org/abs/2110.02178
 * MobileViT-V2 - https://arxiv.org/abs/2206.02680
+* MViT-V2 (Improved Multiscale Vision Transformer) - https://arxiv.org/abs/2112.01526
 * NASNet-A - https://arxiv.org/abs/1707.07012
 * NesT - https://arxiv.org/abs/2105.12723
 * NFNet-F - https://arxiv.org/abs/2102.06171
@@ -273,6 +302,7 @@ A full version of the list below with source links can be found in the [document
 * PNasNet - https://arxiv.org/abs/1712.00559
 * PoolFormer (MetaFormer) - https://arxiv.org/abs/2111.11418
 * Pooling-based Vision Transformer (PiT) - https://arxiv.org/abs/2103.16302
+* PVT-V2 (Improved Pyramid Vision Transformer) - https://arxiv.org/abs/2106.13797
 * RegNet - https://arxiv.org/abs/2003.13678
 * RegNetZ - https://arxiv.org/abs/2103.06877
 * RepVGG - https://arxiv.org/abs/2101.03697

benchmark.py

@@ -19,7 +19,7 @@ import torch.nn as nn
 import torch.nn.parallel
 
 from timm.data import resolve_data_config
-from timm.models import create_model, is_model, list_models
+from timm.models import create_model, is_model, list_models, set_fast_norm
 from timm.optim import create_optimizer_v2
 from timm.utils import setup_default_logging, set_jit_fuser, decay_batch_step, check_batch_size_retry
 
@@ -109,7 +109,8 @@ scripting_group.add_argument('--torchscript', dest='torchscript', action='store_
                     help='convert model torchscript for inference')
 scripting_group.add_argument('--aot-autograd', default=False, action='store_true',
                     help="Enable AOT Autograd support. (It's recommended to use this option with `--fuser nvfuser` together)")
-
+scripting_group.add_argument('--fast-norm', default=False, action='store_true',
+                    help='enable experimental fast-norm')
 
 # train optimizer parameters
 parser.add_argument('--opt', default='sgd', type=str, metavar='OPTIMIZER',
@@ -598,6 +599,9 @@ def main():
     model_cfgs = []
     model_names = []
 
+    if args.fast_norm:
+        set_fast_norm()
+
     if args.model_list:
         args.model = ''
         with open(args.model_list) as f:

timm/models/__init__.py

@@ -69,5 +69,6 @@ from .helpers import load_checkpoint, resume_checkpoint, model_parameters
 from .layers import TestTimePoolHead, apply_test_time_pool
 from .layers import convert_splitbn_model, convert_sync_batchnorm
 from .layers import is_scriptable, is_exportable, set_scriptable, set_exportable, is_no_jit, set_no_jit
+from .layers import set_fast_norm
 from .registry import register_model, model_entrypoint, list_models, is_model, list_modules, is_model_in_modules,\
     is_model_pretrained, get_pretrained_cfg, has_pretrained_cfg_key, is_pretrained_cfg_key, get_pretrained_cfg_value

timm/models/densenet.py

@@ -115,7 +115,7 @@ class DenseBlock(nn.ModuleDict):
     _version = 2
 
     def __init__(
-            self, num_layers, num_input_features, bn_size, growth_rate, norm_layer=nn.ReLU,
+            self, num_layers, num_input_features, bn_size, growth_rate, norm_layer=BatchNormAct2d,
             drop_rate=0., memory_efficient=False):
         super(DenseBlock, self).__init__()
         for i in range(num_layers):
@@ -138,7 +138,7 @@ class DenseBlock(nn.ModuleDict):
 
 
 class DenseTransition(nn.Sequential):
-    def __init__(self, num_input_features, num_output_features, norm_layer=nn.BatchNorm2d, aa_layer=None):
+    def __init__(self, num_input_features, num_output_features, norm_layer=BatchNormAct2d, aa_layer=None):
         super(DenseTransition, self).__init__()
         self.add_module('norm', norm_layer(num_input_features))
         self.add_module('conv', nn.Conv2d(

timm/models/layers/fast_norm.py

@@ -1,3 +1,11 @@
+""" 'Fast' Normalization Functions
+
+For GroupNorm and LayerNorm these functions bypass typical AMP upcast to float32.
+
+Additionally, for LayerNorm, the APEX fused LN is used if available (which also does not upcast)
+
+Hacked together by / Copyright 2022 Ross Wightman
+"""
 from typing import List, Optional
 
 import torch
@@ -37,6 +45,7 @@ def fast_group_norm(
     if torch.is_autocast_enabled():
         # normally native AMP casts GN inputs to float32
         # here we use the low precision autocast dtype
+        # FIXME what to do re CPU autocast?
         dt = torch.get_autocast_gpu_dtype()
         x, weight, bias = x.to(dt), weight.to(dt), bias.to(dt)
 
@@ -62,6 +71,7 @@ def fast_layer_norm(
         # normally native AMP casts LN inputs to float32
         # apex LN does not, this is behaving like Apex
         dt = torch.get_autocast_gpu_dtype()
+        # FIXME what to do re CPU autocast?
         x, weight, bias = x.to(dt), weight.to(dt), bias.to(dt)
 
     with torch.cuda.amp.autocast(enabled=False):

timm/models/layers/norm.py

@@ -1,4 +1,8 @@
 """ Normalization layers and wrappers
+
+Norm layer definitions that support fast norm and consistent channel arg order (always first arg).
+
+Hacked together by / Copyright 2022 Ross Wightman
 """
 
 import torch

timm/models/layers/norm_act.py

@@ -1,4 +1,16 @@
 """ Normalization + Activation Layers
+
+Provides Norm+Act fns for standard PyTorch norm layers such as
+* BatchNorm
+* GroupNorm
+* LayerNorm
+
+This allows swapping with alternative layers that are natively both norm + act such as
+* EvoNorm (evo_norm.py)
+* FilterResponseNorm (filter_response_norm.py)
+* InplaceABN (inplace_abn.py)
+
+Hacked together by / Copyright 2022 Ross Wightman
 """
 from typing import Union, List, Optional, Any
 

timm/models/layers/weight_init.py

@@ -5,7 +5,7 @@ import warnings
 from torch.nn.init import _calculate_fan_in_and_fan_out
 
 
-def _no_grad_trunc_normal_(tensor, mean, std, a, b):
+def _trunc_normal_(tensor, mean, std, a, b):
     # Cut & paste from PyTorch official master until it's in a few official releases - RW
     # Method based on https://people.sc.fsu.edu/~jburkardt/presentations/truncated_normal.pdf
     def norm_cdf(x):
@@ -17,28 +17,27 @@ def _no_grad_trunc_normal_(tensor, mean, std, a, b):
                       "The distribution of values may be incorrect.",
                       stacklevel=2)
 
-    with torch.no_grad():
+    # Values are generated by using a truncated uniform distribution and
-        # Values are generated by using a truncated uniform distribution and
+    # then using the inverse CDF for the normal distribution.
-        # then using the inverse CDF for the normal distribution.
+    # Get upper and lower cdf values
-        # Get upper and lower cdf values
+    l = norm_cdf((a - mean) / std)
-        l = norm_cdf((a - mean) / std)
+    u = norm_cdf((b - mean) / std)
-        u = norm_cdf((b - mean) / std)
 
-        # Uniformly fill tensor with values from [l, u], then translate to
+    # Uniformly fill tensor with values from [l, u], then translate to
-        # [2l-1, 2u-1].
+    # [2l-1, 2u-1].
-        tensor.uniform_(2 * l - 1, 2 * u - 1)
+    tensor.uniform_(2 * l - 1, 2 * u - 1)
 
-        # Use inverse cdf transform for normal distribution to get truncated
+    # Use inverse cdf transform for normal distribution to get truncated
-        # standard normal
+    # standard normal
-        tensor.erfinv_()
+    tensor.erfinv_()
 
-        # Transform to proper mean, std
+    # Transform to proper mean, std
-        tensor.mul_(std * math.sqrt(2.))
+    tensor.mul_(std * math.sqrt(2.))
-        tensor.add_(mean)
+    tensor.add_(mean)
 
-        # Clamp to ensure it's in the proper range
+    # Clamp to ensure it's in the proper range
-        tensor.clamp_(min=a, max=b)
+    tensor.clamp_(min=a, max=b)
-        return tensor
+    return tensor
 
 
 def trunc_normal_(tensor, mean=0., std=1., a=-2., b=2.):
@@ -64,7 +63,8 @@ def trunc_normal_(tensor, mean=0., std=1., a=-2., b=2.):
         >>> w = torch.empty(3, 5)
         >>> nn.init.trunc_normal_(w)
     """
-    return _no_grad_trunc_normal_(tensor, mean, std, a, b)
+    with torch.no_grad():
+        return _trunc_normal_(tensor, mean, std, a, b)
 
 
 def trunc_normal_tf_(tensor, mean=0., std=1., a=-2., b=2.):
@@ -90,8 +90,8 @@ def trunc_normal_tf_(tensor, mean=0., std=1., a=-2., b=2.):
         >>> w = torch.empty(3, 5)
         >>> nn.init.trunc_normal_(w)
     """
-    _no_grad_trunc_normal_(tensor, 0, 1.0, a, b)
     with torch.no_grad():
+        _trunc_normal_(tensor, 0, 1.0, a, b)
         tensor.mul_(std).add_(mean)
     return tensor
 
@@ -111,10 +111,12 @@ def variance_scaling_(tensor, scale=1.0, mode='fan_in', distribution='normal'):
         # constant is stddev of standard normal truncated to (-2, 2)
         trunc_normal_tf_(tensor, std=math.sqrt(variance) / .87962566103423978)
     elif distribution == "normal":
-        tensor.normal_(std=math.sqrt(variance))
+        with torch.no_grad():
+            tensor.normal_(std=math.sqrt(variance))
     elif distribution == "uniform":
         bound = math.sqrt(3 * variance)
-        tensor.uniform_(-bound, bound)
+        with torch.no_grad():
+            tensor.uniform_(-bound, bound)
     else:
         raise ValueError(f"invalid distribution {distribution}")
 

timm/models/maxxvit.py

@@ -39,7 +39,7 @@ Hacked together by / Copyright 2022, Ross Wightman
 
 import math
 from collections import OrderedDict
-from dataclasses import dataclass
+from dataclasses import dataclass, replace
 from functools import partial
 from typing import Callable, Optional, Union, Tuple, List
 
@@ -108,10 +108,13 @@ default_cfgs = {
     # Experimental configs
     'maxvit_pico_rw_256': _cfg(url='', input_size=(3, 256, 256), pool_size=(8, 8)),
     'maxvit_nano_rw_256': _cfg(
-        url='https://github.com/rwightman/pytorch-image-models/releases/download/v0.1-weights-maxx/maxvit_nano_rw_256_sw-3e790ce3.pth',
+        url='https://github.com/rwightman/pytorch-image-models/releases/download/v0.1-weights-maxx/maxvit_nano_rw_256_sw-fb127241.pth',
         input_size=(3, 256, 256), pool_size=(8, 8)),
     'maxvit_tiny_rw_224': _cfg(url=''),
     'maxvit_tiny_rw_256': _cfg(url='', input_size=(3, 256, 256), pool_size=(8, 8)),
+    'maxvit_rmlp_nano_rw_256': _cfg(
+        url='https://github.com/rwightman/pytorch-image-models/releases/download/v0.1-weights-maxx/maxvit_rmlp_nano_rw_256_sw-c17bb0d6.pth',
+        input_size=(3, 256, 256), pool_size=(8, 8)),
     'maxvit_tiny_pm_256': _cfg(url='', input_size=(3, 256, 256), pool_size=(8, 8)),
     'maxxvit_nano_rw_256': _cfg(url='', input_size=(3, 256, 256), pool_size=(8, 8)),
 
@@ -129,21 +132,30 @@ class MaxxVitTransformerCfg:
     dim_head: int = 32
     expand_ratio: float = 4.0
     expand_first: bool = True
-    shortcut_bias: bool = True,
+    shortcut_bias: bool = True
     attn_bias: bool = True
     attn_drop: float = 0.
     proj_drop: float = 0.
     pool_type: str = 'avg2'
     rel_pos_type: str = 'bias'
     rel_pos_dim: int = 512  # for relative position types w/ MLP
-    window_size: Tuple[int, int] = (7, 7)
+    partition_stride: int = 32
-    grid_size: Tuple[int, int] = (7, 7)
+    window_size: Optional[Tuple[int, int]] = None
+    grid_size: Optional[Tuple[int, int]] = None
     init_values: Optional[float] = None
     act_layer: str = 'gelu'
     norm_layer: str = 'layernorm2d'
     norm_layer_cl: str = 'layernorm'
     norm_eps: float = 1e-6
 
+    def __post_init__(self):
+        if self.grid_size is not None:
+            self.grid_size = to_2tuple(self.grid_size)
+        if self.window_size is not None:
+            self.window_size = to_2tuple(self.window_size)
+            if self.grid_size is None:
+                self.grid_size = self.window_size
+
 
 @dataclass
 class MaxxVitConvCfg:
@@ -249,7 +261,7 @@ def _rw_max_cfg(
         conv_norm_layer='',
         transformer_norm_layer='layernorm2d',
         transformer_norm_layer_cl='layernorm',
-        window_size=7,
+        window_size=None,
         dim_head=32,
         rel_pos_type='bias',
         rel_pos_dim=512,
@@ -259,8 +271,6 @@ def _rw_max_cfg(
     # - mbconv expansion calculated from input instead of output chs
     # - mbconv shortcut and final 1x1 conv did not have a bias
     # - mbconv uses silu in timm, not gelu
-    # - avg pool with kernel_size=2 favoured downsampling (instead of maxpool for coat)
-    # - default to avg pool for mbconv downsample instead of 1x1 or dw conv
     # - expansion in attention block done via output proj, not input proj
     return dict(
         conv_cfg=MaxxVitConvCfg(
@@ -276,8 +286,7 @@ def _rw_max_cfg(
             expand_first=False,
             pool_type=pool_type,
             dim_head=dim_head,
-            window_size=to_2tuple(window_size),
+            window_size=window_size,
-            grid_size=to_2tuple(window_size),
             norm_layer=transformer_norm_layer,
             norm_layer_cl=transformer_norm_layer_cl,
             rel_pos_type=rel_pos_type,
@@ -293,7 +302,7 @@ def _next_cfg(
         conv_norm_layer_cl='layernorm',
         transformer_norm_layer='layernorm2d',
         transformer_norm_layer_cl='layernorm',
-        window_size=7,
+        window_size=None,
         rel_pos_type='bias',
         rel_pos_dim=512,
 ):
@@ -310,8 +319,7 @@ def _next_cfg(
         transformer_cfg=MaxxVitTransformerCfg(
             expand_first=False,
             pool_type=pool_type,
-            window_size=to_2tuple(window_size),
+            window_size=window_size,
-            grid_size=to_2tuple(window_size),
             norm_layer=transformer_norm_layer,
             norm_layer_cl=transformer_norm_layer_cl,
             rel_pos_type=rel_pos_type,
@@ -411,18 +419,19 @@ model_cfgs = dict(
             rel_pos_dim=384,  # was supposed to be 512, woops
         ),
     ),
-    coatnext_nano_rw_224=MaxxVitCfg(
+    coatnet_nano_cc_224=MaxxVitCfg(
         embed_dim=(64, 128, 256, 512),
         depths=(3, 4, 6, 3),
         stem_width=(32, 64),
-        **_next_cfg(),
+        block_type=('C', 'C', ('C', 'T'), ('C', 'T')),
+        **_rw_coat_cfg(),
     ),
-    coatnet_nano_cc_224=MaxxVitCfg(
+    coatnext_nano_rw_224=MaxxVitCfg(
         embed_dim=(64, 128, 256, 512),
         depths=(3, 4, 6, 3),
         stem_width=(32, 64),
-        block_type=('C', 'C', ('C', 'T'), ('C', 'T')),
+        weight_init='normal',
-        **_rw_coat_cfg(),
+        **_next_cfg(),
     ),
 
     # Trying to be like the CoAtNet paper configs
@@ -463,14 +472,14 @@ model_cfgs = dict(
         depths=(2, 2, 5, 2),
         block_type=('M',) * 4,
         stem_width=(24, 32),
-        **_rw_max_cfg(window_size=8),
+        **_rw_max_cfg(),
     ),
     maxvit_nano_rw_256=MaxxVitCfg(
         embed_dim=(64, 128, 256, 512),
         depths=(1, 2, 3, 1),
         block_type=('M',) * 4,
         stem_width=(32, 64),
-        **_rw_max_cfg(window_size=8),
+        **_rw_max_cfg(),
     ),
     maxvit_tiny_rw_224=MaxxVitCfg(
         embed_dim=(64, 128, 256, 512),
@@ -484,21 +493,29 @@ model_cfgs = dict(
         depths=(2, 2, 5, 2),
         block_type=('M',) * 4,
         stem_width=(32, 64),
-        **_rw_max_cfg(window_size=8),
+        **_rw_max_cfg(),
+    ),
+    maxvit_rmlp_nano_rw_256=MaxxVitCfg(
+        embed_dim=(64, 128, 256, 512),
+        depths=(1, 2, 3, 1),
+        block_type=('M',) * 4,
+        stem_width=(32, 64),
+        **_rw_max_cfg(rel_pos_type='mlp'),
     ),
     maxvit_tiny_pm_256=MaxxVitCfg(
         embed_dim=(64, 128, 256, 512),
         depths=(2, 2, 5, 2),
         block_type=('PM',) * 4,
         stem_width=(32, 64),
-        **_rw_max_cfg(window_size=8),
+        **_rw_max_cfg(),
     ),
     maxxvit_nano_rw_256=MaxxVitCfg(
         embed_dim=(64, 128, 256, 512),
         depths=(1, 2, 3, 1),
         block_type=('M',) * 4,
         stem_width=(32, 64),
-        **_next_cfg(window_size=8),
+        weight_init='normal',
+        **_next_cfg(),
     ),
 
     # Trying to be like the MaxViT paper configs
@@ -651,7 +668,11 @@ class LayerScale2d(nn.Module):
 
 
 class Downsample2d(nn.Module):
-    """ A downsample pooling module for Coat that handles 2d <-> 1d conversion
+    """ A downsample pooling module supporting several maxpool and avgpool modes
+    * 'max' - MaxPool2d w/ kernel_size 3, stride 2, padding 1
+    * 'max2' - MaxPool2d w/ kernel_size = stride = 2
+    * 'avg' - AvgPool2d w/ kernel_size 3, stride 2, padding 1
+    * 'avg2' - AvgPool2d w/ kernel_size = stride = 2
     """
 
     def __init__(
@@ -710,6 +731,11 @@ def _init_transformer(module, name, scheme=''):
 class TransformerBlock2d(nn.Module):
     """ Transformer block with 2D downsampling
     '2D' NCHW tensor layout
+
+    Some gains can be seen on GPU using a 1D / CL block, BUT w/ the need to switch back/forth to NCHW
+    for spatial pooling, the benefit is minimal so ended up using just this variant for CoAt configs.
+
+    This impl was faster on TPU w/ PT XLA than the 1D experiment.
     """
 
     def __init__(
@@ -1011,9 +1037,9 @@ def get_rel_pos_cls(cfg: MaxxVitTransformerCfg, window_size):
     return rel_pos_cls
 
 
-class PartitionAttention(nn.Module):
+class PartitionAttentionCl(nn.Module):
     """ Grid or Block partition + Attn + FFN.
-    NxC tensor layout.
+    NxC 'channels last' tensor layout.
     """
 
     def __init__(
@@ -1183,6 +1209,7 @@ def grid_reverse_nchw(windows, grid_size: List[int], img_size: List[int]):
 
 class PartitionAttention2d(nn.Module):
     """ Grid or Block partition + Attn + FFN
+
     '2D' NCHW tensor layout.
     """
 
@@ -1245,7 +1272,7 @@ class PartitionAttention2d(nn.Module):
 
 
 class MaxxVitBlock(nn.Module):
-    """
+    """ MaxVit conv, window partition + FFN , grid partition + FFN
     """
 
     def __init__(
@@ -1264,7 +1291,7 @@ class MaxxVitBlock(nn.Module):
         self.conv = conv_cls(dim, dim_out, stride=stride, cfg=conv_cfg, drop_path=drop_path)
 
         attn_kwargs = dict(dim=dim_out, cfg=transformer_cfg, drop_path=drop_path)
-        partition_layer = PartitionAttention2d if use_nchw_attn else PartitionAttention
+        partition_layer = PartitionAttention2d if use_nchw_attn else PartitionAttentionCl
         self.nchw_attn = use_nchw_attn
         self.attn_block = partition_layer(**attn_kwargs)
         self.attn_grid = partition_layer(partition_type='grid', **attn_kwargs)
@@ -1288,7 +1315,8 @@ class MaxxVitBlock(nn.Module):
 
 
 class ParallelMaxxVitBlock(nn.Module):
-    """
+    """ MaxVit block with parallel cat(window + grid), one FF
+    Experimental timm block.
     """
 
     def __init__(
@@ -1426,8 +1454,19 @@ class Stem(nn.Module):
         return x
 
 
+def cfg_window_size(cfg: MaxxVitTransformerCfg, img_size: Tuple[int, int]):
+    if cfg.window_size is not None:
+        assert cfg.grid_size
+        return cfg
+    partition_size = img_size[0] // cfg.partition_stride, img_size[1] // cfg.partition_stride
+    cfg = replace(cfg, window_size=partition_size, grid_size=partition_size)
+    return cfg
+
+
 class MaxxVit(nn.Module):
-    """
+    """ CoaTNet + MaxVit base model.
+
+    Highly configurable for different block compositions, tensor layouts, pooling types.
     """
 
     def __init__(
@@ -1442,6 +1481,7 @@ class MaxxVit(nn.Module):
     ):
         super().__init__()
         img_size = to_2tuple(img_size)
+        transformer_cfg = cfg_window_size(cfg.transformer_cfg, img_size)
         self.num_classes = num_classes
         self.global_pool = global_pool
         self.num_features = cfg.embed_dim[-1]
@@ -1475,7 +1515,7 @@ class MaxxVit(nn.Module):
                 depth=cfg.depths[i],
                 block_types=cfg.block_type[i],
                 conv_cfg=cfg.conv_cfg,
-                transformer_cfg=cfg.transformer_cfg,
+                transformer_cfg=transformer_cfg,
                 feat_size=feat_size,
                 drop_path=dpr[i],
             )]
@@ -1658,6 +1698,11 @@ def maxvit_tiny_rw_256(pretrained=False, **kwargs):
     return _create_maxxvit('maxvit_tiny_rw_256', pretrained=pretrained, **kwargs)
 
 
+@register_model
+def maxvit_rmlp_nano_rw_256(pretrained=False, **kwargs):
+    return _create_maxxvit('maxvit_rmlp_nano_rw_256', pretrained=pretrained, **kwargs)
+
+
 @register_model
 def maxvit_tiny_pm_256(pretrained=False, **kwargs):
     return _create_maxxvit('maxvit_tiny_pm_256', pretrained=pretrained, **kwargs)

timm/models/mvitv2.py

@@ -57,6 +57,8 @@ default_cfgs = dict(
     mvitv2_huge_in21k=_cfg(
         url='https://dl.fbaipublicfiles.com/mvit/mvitv2_models/MViTv2_H_in21k.pyth',
         num_classes=19168),
+
+    mvitv2_small_cls=_cfg(url=''),
 )
 
 
@@ -135,6 +137,11 @@ model_cfgs = dict(
         num_heads=2,
         expand_attn=False,
     ),
+
+    mvitv2_small_cls=MultiScaleVitCfg(
+        depths=(1, 2, 11, 2),
+        use_cls_token=True,
+    ),
 )
 
 
@@ -641,7 +648,7 @@ class MultiScaleBlock(nn.Module):
         if self.shortcut_pool_attn is None:
             return x
         if self.has_cls_token:
-            cls_tok, x = x[:, :, :1, :], x[:, :, 1:, :]
+            cls_tok, x = x[:, :1, :], x[:, 1:, :]
         else:
             cls_tok = None
         B, L, C = x.shape
@@ -650,7 +657,7 @@ class MultiScaleBlock(nn.Module):
         x = self.shortcut_pool_attn(x)
         x = x.reshape(B, C, -1).transpose(1, 2)
         if cls_tok is not None:
-            x = torch.cat((cls_tok, x), dim=2)
+            x = torch.cat((cls_tok, x), dim=1)
         return x
 
     def forward(self, x, feat_size: List[int]):
@@ -996,3 +1003,8 @@ def mvitv2_large(pretrained=False, **kwargs):
 # @register_model
 # def mvitv2_huge_in21k(pretrained=False, **kwargs):
 #     return _create_mvitv2('mvitv2_huge_in21k', pretrained=pretrained, **kwargs)
+
+
+@register_model
+def mvitv2_small_cls(pretrained=False, **kwargs):
+    return _create_mvitv2('mvitv2_small_cls', pretrained=pretrained, **kwargs)