Floating-point operations logging in trainer (#6768)

* neFLOs calculation, logging, and reloading (#1)

* testing distributed consecutive batches

* fixed AttributeError from DataParallel

* removed verbosity

* rotate with use_mtime=True

* removed print

* fixed interaction with gradient accumulation

* indent formatting

* distributed neflo counting

* fixed typo

* fixed typo

* mean distributed losses

* exporting log history

* moved a few functions

* floating_point_ops clarification for transformers with parameter-reuse

* code quality

* double import

* made flo estimation more task-agnostic

* only logging flos if computed

* code quality

* unused import

* Update src/transformers/trainer.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Update src/transformers/modeling_utils.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Sylvain review

* Update src/transformers/modeling_utils.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* black
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

src/transformers/modeling_utils.py

@@ -17,8 +17,9 @@
 import inspect
 import os
 import re
+import warnings
 from dataclasses import dataclass
-from typing import Callable, Dict, List, Optional, Set, Tuple, Union
+from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
 
 import torch
 from torch import Tensor, device, dtype, nn
@@ -45,7 +46,6 @@ from .utils import logging
 
 logger = logging.get_logger(__name__)
 
-
 try:
     from torch.nn import Identity
 except ImportError:
@@ -91,20 +91,6 @@ class ModuleUtilsMixin:
     A few utilities for :obj:`torch.nn.Modules`, to be used as a mixin.
     """
 
-    def num_parameters(self, only_trainable: bool = False) -> int:
-        """
-        Get the number of (optionally, trainable) parameters in the model.
-
-        Args:
-            only_trainable (:obj:`bool`, `optional`, defaults to :obj:`False`):
-                Whether or not to return only the number of trainable parameters
-
-        Returns:
-            :obj:`int`: The number of parameters.
-        """
-        params = filter(lambda x: x.requires_grad, self.parameters()) if only_trainable else self.parameters()
-        return sum(p.numel() for p in params)
-
     @staticmethod
     def _hook_rss_memory_pre_forward(module, *args, **kwargs):
         try:
@@ -307,9 +293,77 @@ class ModuleUtilsMixin:
         elif head_mask.dim() == 2:
             head_mask = head_mask.unsqueeze(1).unsqueeze(-1).unsqueeze(-1)  # We can specify head_mask for each layer
         assert head_mask.dim() == 5, f"head_mask.dim != 5, instead {head_mask.dim()}"
-        head_mask = head_mask.to(dtype=self.dtype)  # switch to fload if need + fp16 compatibility
+        head_mask = head_mask.to(dtype=self.dtype)  # switch to float if need + fp16 compatibility
         return head_mask
 
+    def num_parameters(self, only_trainable: bool = False, exclude_embeddings: bool = False) -> int:
+        """
+        Get number of (optionally, trainable or non-embeddings) parameters in the module.
+
+        Args:
+            only_trainable (:obj:`bool`, `optional`, defaults to :obj:`False`):
+                Whether or not to return only the number of trainable parameters
+
+            exclude_embeddings (:obj:`bool`, `optional`, defaults to :obj:`False`):
+                Whether or not to return only the number of non-embeddings parameters
+
+        Returns:
+            :obj:`int`: The number of parameters.
+        """
+
+        def parameter_filter(x):
+            return (x.requires_grad or not only_trainable) and not (
+                isinstance(x, torch.nn.Embedding) and exclude_embeddings
+            )
+
+        params = filter(parameter_filter, self.parameters()) if only_trainable else self.parameters()
+        return sum(p.numel() for p in params)
+
+    def estimate_tokens(self, input_dict: Dict[str, Union[torch.Tensor, Any]]) -> int:
+        """
+        Helper function to estimate the total number of tokens from the model inputs.
+
+        Args:
+            inputs (:obj:`dict`): The model inputs.
+
+        Returns:
+            :obj:`int`: The total number of tokens.
+        """
+        token_inputs = [tensor for key, tensor in input_dict.items() if "input" in key]
+        if token_inputs:
+            return sum([token_input.numel() for token_input in token_inputs])
+        else:
+            warnings.warn(
+                "Could not estimate the number of tokens of the input, floating-point operations will not be computed"
+            )
+            return 0
+
+    def floating_point_ops(
+        self, input_dict: Dict[str, Union[torch.Tensor, Any]], exclude_embeddings: bool = True
+    ) -> int:
+        """
+        Get number of (optionally, non-embeddings) floating-point operations for the forward and backward passes of a
+        batch with this transformer model. Default approximation neglects the quadratic dependency on the number of
+        tokens (valid if :obj:`12 * d_model << sequence_length`) as laid out in `this paper <https://arxiv.org/pdf/2001.08361.pdf>`__ section
+        2.1. Should be  overriden for transformers with parameter re-use e.g. Albert or Universal Transformers, or
+        if doing long-range modeling with very high sequence lengths.
+
+        Args:
+            batch_size (:obj:`int`):
+                The batch size for the forward pass.
+
+            sequence_length (:obj:`int`):
+                The number of tokens in each line of the batch.
+
+            exclude_embeddings (:obj:`bool`, `optional`, defaults to :obj:`True`):
+                Whether or not to count embedding and softmax operations.
+
+        Returns:
+            :obj:`int`: The number of floating-point operations.
+        """
+
+        return 6 * self.estimate_tokens(input_dict) * self.num_parameters(exclude_embeddings=exclude_embeddings)
+
 
 class PreTrainedModel(nn.Module, ModuleUtilsMixin, GenerationMixin):
     r"""

src/transformers/trainer.py

 import inspect
+import json
 import math
 import os
 import re
@@ -42,6 +43,8 @@ from .trainer_utils import (
     TrainOutput,
     default_compute_objective,
     default_hp_space,
+    distributed_broadcast_scalars,
+    distributed_concat,
     set_seed,
 )
 from .training_args import TrainingArguments
@@ -146,7 +149,7 @@ class SequentialDistributedSampler(Sampler):
         indices = indices[self.rank * self.num_samples : (self.rank + 1) * self.num_samples]
         assert (
             len(indices) == self.num_samples
-        ), f"Indices length {len(indices)} and and sample number {self.num_samples} mismatched"
+        ), f"Indices length {len(indices)} and sample number {self.num_samples} mismatched"
 
         return iter(indices)
 
@@ -241,6 +244,7 @@ class Trainer:
                 "You should subclass `Trainer` and override the `create_optimizer_and_scheduler` method."
             )
         self.tb_writer = tb_writer
+        self.log_history = []
         if "prediction_loss_only" in kwargs:
             warnings.warn(
                 "Passing `prediction_loss_only` as a keyword argument is deprecated and won't be possible in a future version. Use `args.prediction_loss_only` instead.",
@@ -284,6 +288,7 @@ class Trainer:
 
         self.global_step = None
         self.epoch = None
+        self.total_flos = None
         if self.args.fp16 and _use_native_amp:
             self.scaler = torch.cuda.amp.GradScaler()
         self.hp_search_backend = None
@@ -461,7 +466,11 @@ class Trainer:
             logger.info(
                 'Automatic Weights & Biases logging enabled, to disable set os.environ["WANDB_DISABLED"] = "true"'
             )
+            try:
                 combined_dict = {**self.model.config.to_dict(), **self.args.to_sanitized_dict()}
+            except AttributeError:
+                # in case the model has no config
+                combined_dict = {**self.args.to_sanitized_dict()}
             wandb.init(
                 project=os.getenv("WANDB_PROJECT", "huggingface"), config=combined_dict, name=self.args.run_name
             )
@@ -663,6 +672,7 @@ class Trainer:
 
         self.global_step = 0
         self.epoch = 0
+        self.total_flos = 0
         epochs_trained = 0
         steps_trained_in_current_epoch = 0
         # Check if continuing training from a checkpoint
@@ -670,6 +680,8 @@ class Trainer:
             # set global_step to global_step of last saved checkpoint from model path
             try:
                 self.global_step = int(model_path.split("-")[-1].split(os.path.sep)[0])
+                self.total_flos = getattr(model.config, "total_flos", 0)
+
                 epochs_trained = self.global_step // (len(train_dataloader) // self.args.gradient_accumulation_steps)
                 steps_trained_in_current_epoch = self.global_step % (
                     len(train_dataloader) // self.args.gradient_accumulation_steps
@@ -678,9 +690,11 @@ class Trainer:
                 logger.info("  Continuing training from checkpoint, will skip to saved global_step")
                 logger.info("  Continuing training from epoch %d", epochs_trained)
                 logger.info("  Continuing training from global step %d", self.global_step)
+                logger.info("  Continuing training from %d non-embedding floating-point operations", self.total_flos)
                 logger.info("  Will skip the first %d steps in the first epoch", steps_trained_in_current_epoch)
             except ValueError:
                 self.global_step = 0
+                self.total_flos = 0
                 logger.info("  Starting fine-tuning.")
 
         tr_loss = torch.tensor(0.0).to(self.args.device)
@@ -714,6 +728,7 @@ class Trainer:
                     continue
 
                 tr_loss += self.training_step(model, inputs)
+                self.total_flos += self.floating_point_ops(inputs)
 
                 if (step + 1) % self.args.gradient_accumulation_steps == 0 or (
                     # last step in epoch but step is always smaller than gradient_accumulation_steps
@@ -784,7 +799,7 @@ class Trainer:
                         self.save_model(output_dir)
 
                         if self.is_world_process_zero():
-                            self._rotate_checkpoints()
+                            self._rotate_checkpoints(use_mtime=True)
 
                         if is_torch_tpu_available():
                             xm.rendezvous("saving_optimizer_states")
@@ -924,6 +939,13 @@ class Trainer:
 
         if self.epoch is not None:
             logs["epoch"] = self.epoch
+        if self.total_flos is not None:
+            if self.args.local_rank != -1:
+                total_flos = distributed_broadcast_scalars([self.total_flos]).sum().item()
+            else:
+                total_flos = self.total_flos
+            if total_flos > 0:
+                logs["total_flos"] = self.total_flos
         if self.global_step is None:
             # when logging evaluation metrics without training
             self.global_step = 0
@@ -951,6 +973,8 @@ class Trainer:
                 if experiment is not None:
                     experiment._log_metrics(logs, step=self.global_step, epoch=self.epoch, framework="transformers")
         output = {**logs, **{"step": self.global_step}}
+        if self.is_world_process_zero():
+            self.log_history.append(output)
         if iterator is not None:
             iterator.write(output)
         else:
@@ -1089,6 +1113,9 @@ class Trainer:
         if xm.is_master_ordinal():
             os.makedirs(output_dir, exist_ok=True)
             torch.save(self.args, os.path.join(output_dir, "training_args.bin"))
+            json.dump(
+                self.log_history, open(os.path.join(output_dir, "log_history.json"), "w"), indent=2, ensure_ascii=False
+            )
 
         # Save a trained model and configuration using `save_pretrained()`.
         # They can then be reloaded using `from_pretrained()`
@@ -1096,6 +1123,7 @@ class Trainer:
             raise ValueError("Trainer.model appears to not be a PreTrainedModel")
 
         xm.rendezvous("saving_checkpoint")
+        self._store_flos()
         self.model.save_pretrained(output_dir)
         if self.tokenizer is not None:
             self.tokenizer.save_pretrained(output_dir)
@@ -1108,12 +1136,26 @@ class Trainer:
         # They can then be reloaded using `from_pretrained()`
         if not isinstance(self.model, PreTrainedModel):
             raise ValueError("Trainer.model appears to not be a PreTrainedModel")
+        self._store_flos()
         self.model.save_pretrained(output_dir)
         if self.tokenizer is not None:
             self.tokenizer.save_pretrained(output_dir)
 
         # Good practice: save your training arguments together with the trained model
         torch.save(self.args, os.path.join(output_dir, "training_args.bin"))
+        json.dump(
+            self.log_history, open(os.path.join(output_dir, "log_history.json"), "w"), indent=2, ensure_ascii=False
+        )
+
+    def _store_flos(self):
+        # Storing the number of floating-point operations that went into the model
+        if self.total_flos is not None:
+            if self.args.local_rank != -1:
+                total_flos = distributed_broadcast_scalars([self.total_flos]).sum().item()
+            else:
+                total_flos = self.total_flos
+            if total_flos > 0:
+                self.model.config.total_flos = total_flos
 
     def _sorted_checkpoints(self, checkpoint_prefix=PREFIX_CHECKPOINT_DIR, use_mtime=False) -> List[str]:
         ordering_and_checkpoint_path = []
@@ -1245,13 +1287,11 @@ class Trainer:
             self._past = None
 
         disable_tqdm = not self.is_local_process_zero() or self.args.disable_tqdm
-        samples_count = 0
         for inputs in tqdm(dataloader, desc=description, disable=disable_tqdm):
             loss, logits, labels = self.prediction_step(model, inputs, prediction_loss_only)
             batch_size = inputs[list(inputs.keys())[0]].shape[0]
-            samples_count += batch_size
             if loss is not None:
-                eval_losses.append(loss * batch_size)
+                eval_losses.extend([loss] * batch_size)
             if logits is not None:
                 preds = logits if preds is None else torch.cat((preds, logits), dim=0)
             if labels is not None:
@@ -1264,9 +1304,9 @@ class Trainer:
         if self.args.local_rank != -1:
             # In distributed mode, concatenate all results from all nodes:
             if preds is not None:
-                preds = self.distributed_concat(preds, num_total_examples=self.num_examples(dataloader))
+                preds = distributed_concat(preds, num_total_examples=self.num_examples(dataloader))
             if label_ids is not None:
-                label_ids = self.distributed_concat(label_ids, num_total_examples=self.num_examples(dataloader))
+                label_ids = distributed_concat(label_ids, num_total_examples=self.num_examples(dataloader))
         elif is_torch_tpu_available():
             # tpu-comment: Get all predictions and labels from all worker shards of eval dataset
             if preds is not None:
@@ -1289,7 +1329,14 @@ class Trainer:
         else:
             metrics = {}
         if len(eval_losses) > 0:
-            metrics["eval_loss"] = np.sum(eval_losses) / samples_count
+            if self.args.local_rank != -1:
+                metrics["eval_loss"] = (
+                    distributed_broadcast_scalars(eval_losses, num_total_examples=self.num_examples(dataloader))
+                    .mean()
+                    .item()
+                )
+            else:
+                metrics["eval_loss"] = np.mean(eval_losses)
 
         # Prefix all keys with eval_
         for key in list(metrics.keys()):
@@ -1298,18 +1345,6 @@ class Trainer:
 
         return PredictionOutput(predictions=preds, label_ids=label_ids, metrics=metrics)
 
-    def distributed_concat(self, tensor: torch.Tensor, num_total_examples: int) -> torch.Tensor:
-        assert self.args.local_rank != -1
-
-        output_tensors = [tensor.clone() for _ in range(torch.distributed.get_world_size())]
-        torch.distributed.all_gather(output_tensors, tensor)
-
-        concat = torch.cat(output_tensors, dim=0)
-
-        # truncate the dummy elements added by SequentialDistributedSampler
-        output = concat[:num_total_examples]
-        return output
-
     def prediction_step(
         self, model: nn.Module, inputs: Dict[str, Union[torch.Tensor, Any]], prediction_loss_only: bool
     ) -> Tuple[Optional[float], Optional[torch.Tensor], Optional[torch.Tensor]]:
@@ -1355,3 +1390,32 @@ class Trainer:
         if labels is not None:
             labels = labels.detach()
         return (loss, logits.detach(), labels)
+
+    def floating_point_ops(self, inputs: Dict[str, Union[torch.Tensor, Any]]):
+        """
+        For models that inherit from :class:`~transformers.PretrainedModel`, uses
+        that method to compute the number of floating point operations for every backward + forward pass. If using
+        another model, either implement such a method in the model or subclass and override this method.
+
+        Args:
+            model (:obj:`nn.Module`):
+                The model to evaluate.
+            inputs (:obj:`Dict[str, Union[torch.Tensor, Any]]`):
+                The inputs and targets of the model.
+
+        Returns:
+            :obj:`int`: The number of floating-point operations.
+        """
+
+        if isinstance(self.model, torch.nn.DataParallel) or isinstance(
+            self.model, torch.nn.parallel.DistributedDataParallel
+        ):
+            model = self.model.module
+        else:
+            model = self.model
+
+        if hasattr(model, "floating_point_ops"):
+            return model.floating_point_ops(inputs)
+
+        else:
+            return 0

src/transformers/trainer_utils.py

 import random
-from typing import Any, Dict, NamedTuple, Optional
+from typing import Any, Dict, List, NamedTuple, Optional, Union
 
 import numpy as np
+import torch
 
 from .file_utils import is_tf_available, is_torch_available
 from .tokenization_utils_base import ExplicitEnum
@@ -126,3 +127,32 @@ default_hp_space = {
     HPSearchBackend.OPTUNA: default_hp_space_optuna,
     HPSearchBackend.RAY: default_hp_space_ray,
 }
+
+
+def distributed_concat(self, tensor: torch.Tensor, num_total_examples: Optional[int] = None) -> torch.Tensor:
+    assert self.args.local_rank != -1
+
+    output_tensors = [tensor.clone() for _ in range(torch.distributed.get_world_size())]
+    torch.distributed.all_gather(output_tensors, tensor)
+    concat = torch.cat(output_tensors, dim=0)
+
+    # truncate the dummy elements added by SequentialDistributedSampler
+    if num_total_examples is not None:
+        concat = concat[:num_total_examples]
+    return concat
+
+
+def distributed_broadcast_scalars(
+    self, scalars: List[Union[int, float]], num_total_examples: Optional[int] = None
+) -> torch.Tensor:
+    assert self.args.local_rank != -1
+
+    tensorized_scalar = torch.Tensor(scalars).cuda()
+    output_tensors = [tensorized_scalar.clone() for _ in range(torch.distributed.get_world_size())]
+    torch.distributed.all_gather(output_tensors, tensorized_scalar)
+    concat = torch.cat(output_tensors, dim=0)
+
+    # truncate the dummy elements added by SequentialDistributedSampler
+    if num_total_examples is not None:
+        concat = concat[:num_total_examples]
+    return concat