[Features] Add logger for initialization of parameters

mmcv/cnn/utils/weight_init.py

@@ -8,6 +8,7 @@
 import torch.nn as nn
 from torch import Tensor
 
+from mmcv.runner.base_module import update_init_info
 from mmcv.utils import Registry, build_from_cfg, get_logger, print_log
 
 INITIALIZERS = Registry('initializer')
@@ -122,6 +123,10 @@ def __init__(self, *, bias=0, bias_prob=None, layer=None):
             self.bias = bias
         self.layer = [layer] if isinstance(layer, str) else layer
 
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}, bias={self.bias}'
+        return info
+
 
 @INITIALIZERS.register_module(name='Constant')
 class ConstantInit(BaseInit):
@@ -152,6 +157,12 @@ def init(m):
                     constant_init(m, self.val, self.bias)
 
         module.apply(init)
+        if hasattr(module, '_params_init_info'):
+            update_init_info(module, init_info=self._get_init_info())
+
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}: val={self.val}, bias={self.bias}'
+        return info
 
 
 @INITIALIZERS.register_module(name='Xavier')
@@ -189,6 +200,13 @@ def init(m):
                     xavier_init(m, self.gain, self.bias, self.distribution)
 
         module.apply(init)
+        if hasattr(module, '_params_init_info'):
+            update_init_info(module, init_info=self._get_init_info())
+
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}: gain={self.gain}, ' \
+               f'distribution={self.distribution}, bias={self.bias}'
+        return info
 
 
 @INITIALIZERS.register_module(name='Normal')
@@ -225,6 +243,13 @@ def init(m):
                     normal_init(m, self.mean, self.std, self.bias)
 
         module.apply(init)
+        if hasattr(module, '_params_init_info'):
+            update_init_info(module, init_info=self._get_init_info())
+
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}: mean={self.mean},' \
+               f' std={self.std}, bias={self.bias}'
+        return info
 
 
 @INITIALIZERS.register_module(name='TruncNormal')
@@ -273,6 +298,13 @@ def init(m):
                                       self.bias)
 
         module.apply(init)
+        if hasattr(module, '_params_init_info'):
+            update_init_info(module, init_info=self._get_init_info())
+
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}: a={self.a}, b={self.b},' \
+               f' mean={self.mean}, std={self.std}, bias={self.bias}'
+        return info
 
 
 @INITIALIZERS.register_module(name='Uniform')
@@ -309,6 +341,13 @@ def init(m):
                     uniform_init(m, self.a, self.b, self.bias)
 
         module.apply(init)
+        if hasattr(module, '_params_init_info'):
+            update_init_info(module, init_info=self._get_init_info())
+
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}: a={self.a},' \
+               f' b={self.b}, bias={self.bias}'
+        return info
 
 
 @INITIALIZERS.register_module(name='Kaiming')
@@ -364,6 +403,14 @@ def init(m):
                                  self.bias, self.distribution)
 
         module.apply(init)
+        if hasattr(module, '_params_init_info'):
+            update_init_info(module, init_info=self._get_init_info())
+
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}: a={self.a}, mode={self.mode}, ' \
+               f'nonlinearity={self.nonlinearity}, ' \
+               f'distribution ={self.distribution}, bias={self.bias}'
+        return info
 
 
 @INITIALIZERS.register_module(name='Caffe2Xavier')
@@ -422,6 +469,13 @@ def __call__(self, module):
                 self.prefix, self.checkpoint, map_location=self.map_location)
             load_state_dict(module, state_dict, strict=False, logger=logger)
 
+        if hasattr(module, '_params_init_info'):
+            update_init_info(module, init_info=self._get_init_info())
+
+    def _get_init_info(self):
+        info = f'{self.__class__.__name__}: load from {self.checkpoint}'
+        return info
+
 
 def _initialize(module, cfg, wholemodule=False):
     func = build_from_cfg(cfg, INITIALIZERS)

mmcv/runner/base_module.py

@@ -1,30 +1,74 @@
 # Copyright (c) Open-MMLab. All rights reserved.
+import copy
 import warnings
 from abc import ABCMeta
+from collections import defaultdict
+from logging import FileHandler
 
 import torch.nn as nn
 
-from mmcv import ConfigDict
+from mmcv.runner.dist_utils import master_only
+from mmcv.utils.logging import get_logger, logger_initialized, print_log
+
+
+def update_init_info(module, *, init_info):
+    """Update the `_params_init_info` in the module if the value of parameters
+    are changed.
+
+    Args:
+        module (obj:`nn.Module`): The module of PyTorch with a user-defined
+            attribute `_params_init_info` which records the initialization
+            information.
+        init_info (str): The string that describes the initialization.
+    """
+    for param in module.parameters():
+        mean_value = param.data.mean()
+        if module._params_init_info[param]['tmp_mean_value'] != mean_value:
+            module._params_init_info[param]['init_info'] = init_info
+            module._params_init_info[param]['tmp_mean_value'] = mean_value
 
 
 class BaseModule(nn.Module, metaclass=ABCMeta):
-    """Base module for all modules in openmmlab."""
+    """Base module for all modules in openmmlab.
 
-    def __init__(self, init_cfg=None):
-        """Initialize BaseModule, inherited from `torch.nn.Module`
+    ``BaseModule`` is a wrapper of ``torch.nn.Module`` with additional
+    functionality of parameter initialization. Compared with
+    ``torch.nn.Module``, ``BaseModule`` mainly adds three attributes.
 
-        Args:
-            init_cfg (dict, optional): Initialization config dict.
-        """
+        - ``init_cfg``: the config to control the initialization.
+        - ``_params_init_info``: Used to track the parameter
+            initialization information.
+        - ``init_weights``: The function of parameter
+            initialization and recording initialization
+            information.
+
+    Args:
+        init_cfg (dict, optional): Initialization config dict.
+    """
+
+    def __init__(self, init_cfg=None):
+        """Initialize BaseModule, inherited from `torch.nn.Module`"""
 
         # NOTE init_cfg can be defined in different levels, but init_cfg
         # in low levels has a higher priority.
 
         super(BaseModule, self).__init__()
         # define default value of init_cfg instead of hard code
-        # in init_weight() function
+        # in init_weights() function
         self._is_init = False
-        self.init_cfg = init_cfg
+
+        self.init_cfg = copy.deepcopy(init_cfg)
+
+        # The `_params_init_info` is used to record the initialization
+        # information of the parameters
+        # the key should be the obj:`nn.Parameter` of model and the value
+        # should be a dict containing
+        # - param_name (str): The name of parameter.
+        # - init_info (str): The string that describes the initialization.
+        # - tmp_mean_value (FloatTensor): The mean of the parameter,
+        #       which indicates whether the parameter has been modified.
+        # this attribute would be deleted after all parameters is initialized.
+        self._params_init_info = defaultdict(dict)
 
         # Backward compatibility in derived classes
         # if pretrained is not None:
@@ -38,26 +82,100 @@ def is_init(self):
 
     def init_weights(self):
         """Initialize the weights."""
-        from ..cnn import initialize
 
+        # check if it is top-level module
+        is_top_level_module = len(self._params_init_info) == 0
+        if is_top_level_module:
+            # Initialize the `_params_init_info`,
+            # When detecting the `tmp_mean_value` of
+            # the corresponding parameter is changed, update related
+            # initialization information
+            for name, param in self.named_parameters():
+                self._params_init_info[param]['param_name'] = name
+                self._params_init_info[param][
+                    'init_info'] = f'The value is the same before and ' \
+                                   f'after calling `init_weights` ' \
+                                   f'of {self.__class__.__name__} '
+                self._params_init_info[param][
+                    'tmp_mean_value'] = param.data.mean()
+
+            # pass `params_init_info` to all submodules
+            # All submodules share the same `params_init_info`,
+            # so it will be updated when parameters are
+            # modified at any level of the model.
+            for sub_module in self.modules():
+                sub_module._params_init_info = self._params_init_info
+
+        # Get the initialized logger, if not exist,
+        # create a logger named `mmcv`
+        logger_names = list(logger_initialized.keys())
+        logger_name = logger_names[0] if logger_names else 'mmcv'
+
+        from ..cnn import initialize
+        module_name = self.__class__.__name__
         if not self._is_init:
             if self.init_cfg:
+                print_log(
+                    f'initialize {module_name} with init_cfg {self.init_cfg}',
+                    logger=logger_name)
                 initialize(self, self.init_cfg)
-                if isinstance(self.init_cfg, (dict, ConfigDict)):
-                    # Avoid the parameters of the pre-training model
-                    # being overwritten by the init_weights
-                    # of the children.
+                if isinstance(self.init_cfg, dict):
+                    # prevent the parameters of
+                    # the pre-trained model
+                    # from being overwritten by
+                    # the `init_weights`
                     if self.init_cfg['type'] == 'Pretrained':
                         return
 
             for m in self.children():
                 if hasattr(m, 'init_weights'):
                     m.init_weights()
+                    # users may overload the `init_weights`
+                    update_init_info(
+                        m,
+                        init_info=f'Initialized by '
+                        f'user-defined `init_weights`'
+                        f' in {m.__class__.__name__} ')
+
             self._is_init = True
         else:
             warnings.warn(f'init_weights of {self.__class__.__name__} has '
                           f'been called more than once.')
 
+        if is_top_level_module:
+            self._dump_init_info(logger_name)
+
+            for sub_module in self.modules():
+                del sub_module._params_init_info
+
+    @master_only
+    def _dump_init_info(self, logger_name):
+        """Dump the initialization information to a file named
+        `initialization.log.json` in workdir.
+
+        Args:
+            logger_name (str): The name of logger.
+        """
+
+        logger = get_logger(logger_name)
+
+        with_file_handler = False
+        # dump the information to the logger file if there is a `FileHandler`
+        for handler in logger.handlers:
+            if isinstance(handler, FileHandler):
+                handler.stream.write(
+                    'Name of parameter - Initialization information\n')
+                for item in list(self._params_init_info.values()):
+                    handler.stream.write(
+                        f"{item['param_name']} - {item['init_info']} \n")
+                handler.stream.flush()
+                with_file_handler = True
+        if not with_file_handler:
+            for item in list(self._params_init_info.values()):
+                print_log(
+                    f"{item['param_name']} - {item['init_info']}",
+                    logger=logger_name)
+
     def __repr__(self):
         s = super().__repr__()
         if self.init_cfg: