sophia exp

labml_nn/optimizers/configs.py

@@ -67,6 +67,8 @@ class OptimizerConfigs(BaseConfigs):
     # Model embedding size for Noam optimizer
     d_model: int
 
+    rho: float
+
     def __init__(self):
         super().__init__(_primary='optimizer')
 
@@ -137,6 +139,14 @@ def _noam_optimizer(c: OptimizerConfigs):
                 d_model=c.d_model)
 
 
+@option(OptimizerConfigs.optimizer, 'Sophia')
+def _sophia_optimizer(c: OptimizerConfigs):
+    from labml_nn.optimizers.sophia import Sophia
+    return Sophia(c.parameters,
+                  lr=c.learning_rate, betas=c.betas, eps=c.eps,
+                  weight_decay=c.weight_decay_obj, rho=c.rho)
+
+
 @option(OptimizerConfigs.optimizer, 'AdamWarmupCosineDecay')
 def _noam_optimizer(c: OptimizerConfigs):
     from labml_nn.optimizers.adam_warmup_cosine_decay import AdamWarmupCosineDecay

labml_nn/optimizers/sophia.py

@@ -29,9 +29,7 @@ class Sophia(GenericAdaptiveOptimizer):
     def __init__(self, params,
                  lr: float = 1e-4, betas: Tuple[float, float] = (0.965, 0.99), eps: float = 1e-16,
                  rho: float = 0.04,
-                 training_batch_tokens: int = None,
                  weight_decay: WeightDecay = WeightDecay(),
-                 optimized_update: bool = True,
                  defaults: Optional[Dict[str, Any]] = None):
         """
         ### Initialize the optimizer
@@ -42,21 +40,15 @@ class Sophia(GenericAdaptiveOptimizer):
         * `eps` is $\epsilon$
         * `pho` is $\rho$
         * `weight_decay` is an instance of class `WeightDecay` defined in [`__init__.py`](index.html)
-        * `optimized_update` is a flag whether to optimize the bias correction of the second moment
-          by doing it after adding $\epsilon$
         * `defaults` is a dictionary of default for group values.
          This is useful when you want to extend the class `Adam`.
         """
-        if training_batch_tokens is None:
-            raise RuntimeError('Please set the number of tokens per training batch.')
-
         defaults = {} if defaults is None else defaults
         defaults.update(weight_decay.defaults())
-        defaults.update(dict(rho=rho, training_batch_tokens=training_batch_tokens))
+        defaults.update(dict(rho=rho))
         super().__init__(params, defaults, lr, betas, eps)
 
         self.weight_decay = weight_decay
-        self.optimized_update = optimized_update
 
     def init_state(self, state: Dict[str, any], group: Dict[str, any], param: nn.Parameter):
         """
@@ -75,7 +67,7 @@ class Sophia(GenericAdaptiveOptimizer):
         # Exponential moving average of Hessian
         state['hessian'] = torch.zeros_like(param, memory_format=torch.preserve_format)
 
-    def update_hessian(self, batch_size):
+    def update_hessian(self, n_tokens_training_batch):
         for group in self.param_groups:
             beta1, beta2 = group['betas']
             for p in group['params']:
@@ -86,7 +78,7 @@ class Sophia(GenericAdaptiveOptimizer):
                 if len(state) == 0:
                     self.init_state(state, group, p)
 
-                state['hessian'].mul_(beta2).addcmul_(p.grad, p.grad, value=(1 - beta2) * batch_size)
+                state['hessian'].mul_(beta2).addcmul_(p.grad, p.grad, value=(1 - beta2) * n_tokens_training_batch)
 
     def step_param(self, state: Dict[str, any], group: Dict[str, any], grad: torch.Tensor, param: torch.nn.Parameter):
         """
@@ -107,7 +99,7 @@ class Sophia(GenericAdaptiveOptimizer):
         rho = group['rho']
 
         # Get $m_{t-1}$ and $v_{t-1}$
-        m, hessian = state['exp_avg'], state['hessain']
+        m, hessian = state['exp_avg'], state['hessian']
 
         # In-place calculation of $m_t$
         # $$m_t \leftarrow \beta_1 m_{t-1} + (1 - \beta_1) \cdot g_t$$
@@ -119,6 +111,6 @@ class Sophia(GenericAdaptiveOptimizer):
         # Get learning rate
         lr = group['lr']
 
-        ratio = (m.abs() / (rho * hessian + group['training_batch_tokens'] * group['eps'])).clamp(None, 1)
+        ratio = (m.abs() / (rho * hessian + group['eps'])).clamp(None, 1)
 
         param.data.addcmul_(m.sign(), ratio, value=-lr)

labml_nn/transformers/basic/with_sophia.py

@@ -0,0 +1,147 @@
+import torch
+from labml.configs import option
+
+from labml import experiment, tracker
+from labml_helpers.train_valid import BatchIndex
+from labml_nn.optimizers.sophia import Sophia
+from labml_nn.transformers.basic.autoregressive_experiment import Configs as TransformerAutoRegressionConfigs
+
+
+class Configs(TransformerAutoRegressionConfigs):
+    """
+    ## Configurations
+
+    This inherits from [`Configs`](autoregressive_experiment.html)
+    """
+
+    hess_interval: int = 10
+
+    optimizer: Sophia
+
+    def step(self, batch: any, batch_idx: BatchIndex):
+        """
+        ### Training or validation step
+        """
+
+        # Set training/eval mode
+        self.model.train(self.mode.is_train)
+
+        # Move data to the device
+        data, target = batch[0].to(self.device), batch[1].to(self.device)
+
+        if isinstance(self.optimizer, Sophia) and self.mode.is_train and batch_idx.idx % self.hess_interval == 0:
+            # Whether to capture model outputs
+            with self.mode.update(is_log_activations=False):
+                # Get model outputs.
+                # It's returning a tuple for states when using RNNs.
+                # This is not implemented yet. 😜
+                output, *_ = self.model(data)
+
+            samp_dist = torch.distributions.Categorical(logits=output)
+            y_sample = samp_dist.sample()
+
+            # Calculate and log loss
+            loss = self.loss_func(output, y_sample)
+            tracker.add("loss.hess.", loss)
+
+            # Calculate gradients
+            loss.backward()
+            # Clip gradients
+            torch.nn.utils.clip_grad_norm_(self.model.parameters(), max_norm=self.grad_norm_clip)
+            # Update Hessian estimate
+            self.optimizer.update_hessian(data.numel())
+            # Clear the gradients
+            self.optimizer.zero_grad()
+        else:
+            # Move data to the device
+            data, target = batch[0].to(self.device), batch[1].to(self.device)
+
+            # Update global step (number of tokens processed) when in training mode
+            if self.mode.is_train:
+                tracker.add_global_step(data.shape[0] * data.shape[1])
+
+            # Whether to capture model outputs
+            with self.mode.update(is_log_activations=batch_idx.is_last and self.is_log_model_activations):
+                # Get model outputs.
+                # It's returning a tuple for states when using RNNs.
+                # This is not implemented yet. 😜
+                output, *_ = self.model(data)
+
+            # Calculate and log loss
+            loss = self.loss_func(output, target)
+            tracker.add("loss.", loss)
+
+            # Calculate and log accuracy
+            self.accuracy(output, target)
+            self.accuracy.track()
+
+            self.other_metrics(output, target)
+
+            # Train the model
+            if self.mode.is_train:
+                # Calculate gradients
+                loss.backward()
+                # Clip gradients
+                torch.nn.utils.clip_grad_norm_(self.model.parameters(), max_norm=self.grad_norm_clip)
+                # Take optimizer step
+                self.optimizer.step()
+                # Log the model parameters and gradients on last batch of every epoch
+                if batch_idx.is_last and self.is_log_model_params_grads:
+                    tracker.add('model', self.model)
+                # Clear the gradients
+                self.optimizer.zero_grad()
+
+            # Save the tracked metrics
+            tracker.save()
+
+
+
+def main():
+    # Create experiment
+    experiment.create(name="transformer")
+    # Create configs
+    conf = Configs()
+    # Override configurations
+    experiment.configs(conf, {
+        # Use character level tokenizer
+        'tokenizer': 'character',
+        # Prompt separator is blank
+        'prompt_separator': '',
+        # Starting prompt for sampling
+        'prompt': 'It is ',
+        # Use Tiny Shakespeare dataset
+        'text': 'tiny_shakespeare',
+
+        # Use a context size of $256$
+        'seq_len': 512,
+        # Train for 32 epochs
+        'epochs': 32,
+        # Batch size $32$
+        'batch_size': 16,
+        # Switch between training and validation for $10$ times
+        # per epoch
+        'inner_iterations': 10,
+
+        # Model size
+        'd_model': 256,
+        'transformer.n_heads': 16,
+        'transformer.ffn.d_ff': 1024,
+
+        # Use [Noam optimizer](../../optimizers/noam.html)
+        'optimizer.optimizer': 'Sophia',
+        'optimizer.learning_rate': 3e-4,
+        'optimizer.rho': 0.03,
+    })
+
+    # Set models for saving and loading
+    experiment.add_pytorch_models({'model': conf.model})
+
+    # Start the experiment
+    with experiment.start():
+        # Run training
+        conf.run()
+
+
+#
+if __name__ == '__main__':
+    main()