Method eval_batch

deepspeed/runtime/pipe/engine.py:431–518

Evaluate the pipeline on a batch of data from ``data_iter``. The engine will evaluate ``self.train_batch_size()`` total samples collectively across all workers. This method is equivalent to: .. code-block:: python module.eval() with torch.no

(self,
                   data_iter,
                   return_logits=False,
                   compute_loss=True,
                   reduce_output='avg',
                   bcast_loss=True,
                   num_micro_batches=None)

        return self.agg_train_loss

    def eval_batch(self,
                   data_iter,
                   return_logits=False,
                   compute_loss=True,
                   reduce_output='avg',
                   bcast_loss=True,
                   num_micro_batches=None):
        """Evaluate the pipeline on a batch of data from ``data_iter``. The
        engine will evaluate ``self.train_batch_size()`` total samples
        collectively across all workers.

        This method is equivalent to:

        .. code-block:: python

            module.eval()
            with torch.no_grad():
                output = module(batch)

        .. warning::
            A total of ``self.gradient_accumulation_steps()`` entries will be pulled
            from ``data_iter`` by each pipeline. There must be sufficient
            data left in ``data_iter`` or else a ``StopIteration`` will halt training.

            DeepSpeed provides a convenience class :class:`deepspeed.utils.RepeatingLoader`
            that wraps data loaders to automatically restart upon a ``StopIteration``.

        Args:
            data_iter (Iterator): Iterator of data to evaluate.

        Returns:
            The arithmetic mean of the losses computed this batch.
        """
        self.eval_return_logits = return_logits
        self.module.eval()

        # Curriculum learning could change activation shape
        if self.curriculum_enabled_legacy():
            new_difficulty = self.curriculum_scheduler_legacy.update_difficulty( \
                self.global_steps + 1)
            if self.global_steps == 0 or self.curriculum_scheduler_legacy.first_step:
                self.reset_activation_shape()
                self.curriculum_scheduler_legacy.first_step = False
            elif new_difficulty != self.curriculum_scheduler_legacy.get_difficulty( \
                self.global_steps):
                self.reset_activation_shape()

        eval_output = None

        self._compute_loss = compute_loss

        # Use the provided data iterator
        train_iterator = self.data_iterator
        self.set_dataiterator(data_iter)

        # set the number micro batches in case the user chose value than training
        micro_batches = self.micro_batches if num_micro_batches is None else num_micro_batches