Support ratios for `logging_steps`, `eval_steps`, and `save_steps` (#23235)

* Ratio option for `logging_steps`, `eval_steps`, `save_steps`

* Add guards if arguments are not set

* Add more detailed comments + formatting

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

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

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

* Convert args values to `int` if bigger than 1

* `black`

* `make fixup`

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

src/transformers/trainer.py

@@ -1712,6 +1712,14 @@ class Trainer:
                 f" {args.max_steps}"
             )
 
+        # Compute absolute values for logging, eval, and save if given as ratio
+        if args.logging_steps and args.logging_steps < 1:
+            args.logging_steps = math.ceil(max_steps * args.logging_steps)
+        if args.eval_steps and args.eval_steps < 1:
+            args.eval_steps = math.ceil(max_steps * args.eval_steps)
+        if args.save_steps and args.save_steps < 1:
+            args.save_steps = math.ceil(max_steps * args.save_steps)
+
         if DebugOption.UNDERFLOW_OVERFLOW in self.args.debug:
             if self.args.n_gpu > 1:
                 # nn.DataParallel(model) replicates the model, creating new variables and module

src/transformers/training_args.py

@@ -251,8 +251,9 @@ class TrainingArguments:
 
         logging_first_step (`bool`, *optional*, defaults to `False`):
             Whether to log and evaluate the first `global_step` or not.
-        logging_steps (`int`, *optional*, defaults to 500):
-            Number of update steps between two logs if `logging_strategy="steps"`.
+        logging_steps (`int` or `float`, *optional*, defaults to 500):
+            Number of update steps between two logs if `logging_strategy="steps"`. Should be an integer or a float in
+            range `[0,1)`. If smaller than 1, will be interpreted as ratio of total training steps.
         logging_nan_inf_filter (`bool`, *optional*, defaults to `True`):
             Whether to filter `nan` and `inf` losses for logging. If set to `True` the loss of every step that is `nan`
             or `inf` is filtered and the average loss of the current logging window is taken instead.
@@ -270,8 +271,9 @@ class TrainingArguments:
                 - `"no"`: No save is done during training.
                 - `"epoch"`: Save is done at the end of each epoch.
                 - `"steps"`: Save is done every `save_steps`.
-        save_steps (`int`, *optional*, defaults to 500):
-            Number of updates steps before two checkpoint saves if `save_strategy="steps"`.
+        save_steps (`int` or `float`, *optional*, defaults to 500):
+            Number of updates steps before two checkpoint saves if `save_strategy="steps"`. Should be an integer or a
+            float in range `[0,1)`. If smaller than 1, will be interpreted as ratio of total training steps.
         save_total_limit (`int`, *optional*):
             If a value is passed, will limit the total amount of checkpoints. Deletes the older checkpoints in
             `output_dir`.
@@ -332,9 +334,10 @@ class TrainingArguments:
         dataloader_drop_last (`bool`, *optional*, defaults to `False`):
             Whether to drop the last incomplete batch (if the length of the dataset is not divisible by the batch size)
             or not.
-        eval_steps (`int`, *optional*):
+        eval_steps (`int` or `float`, *optional*):
             Number of update steps between two evaluations if `evaluation_strategy="steps"`. Will default to the same
-            value as `logging_steps` if not set.
+            value as `logging_steps` if not set. Should be an integer or a float in range `[0,1)`. If smaller than 1,
+            will be interpreted as ratio of total training steps.
         dataloader_num_workers (`int`, *optional*, defaults to 0):
             Number of subprocesses to use for data loading (PyTorch only). 0 means that the data will be loaded in the
             main process.
@@ -721,13 +724,29 @@ class TrainingArguments:
         metadata={"help": "The logging strategy to use."},
     )
     logging_first_step: bool = field(default=False, metadata={"help": "Log the first global_step"})
-    logging_steps: int = field(default=500, metadata={"help": "Log every X updates steps."})
+    logging_steps: float = field(
+        default=500,
+        metadata={
+            "help": (
+                "Log every X updates steps. Should be an integer or a float in range `[0,1)`."
+                "If smaller than 1, will be interpreted as ratio of total training steps."
+            )
+        },
+    )
     logging_nan_inf_filter: bool = field(default=True, metadata={"help": "Filter nan and inf losses for logging."})
     save_strategy: Union[IntervalStrategy, str] = field(
         default="steps",
         metadata={"help": "The checkpoint save strategy to use."},
     )
-    save_steps: int = field(default=500, metadata={"help": "Save checkpoint every X updates steps."})
+    save_steps: float = field(
+        default=500,
+        metadata={
+            "help": (
+                "Save checkpoint every X updates steps. Should be an integer or a float in range `[0,1)`."
+                "If smaller than 1, will be interpreted as ratio of total training steps."
+            )
+        },
+    )
     save_total_limit: Optional[int] = field(
         default=None,
         metadata={
@@ -854,7 +873,15 @@ class TrainingArguments:
     dataloader_drop_last: bool = field(
         default=False, metadata={"help": "Drop the last incomplete batch if it is not divisible by the batch size."}
     )
-    eval_steps: Optional[int] = field(default=None, metadata={"help": "Run an evaluation every X steps."})
+    eval_steps: Optional[float] = field(
+        default=None,
+        metadata={
+            "help": (
+                "Run an evaluation every X steps. Should be an integer or a float in range `[0,1)`."
+                "If smaller than 1, will be interpreted as ratio of total training steps."
+            )
+        },
+    )
     dataloader_num_workers: int = field(
         default=0,
         metadata={
@@ -1186,6 +1213,19 @@ class TrainingArguments:
         if self.logging_strategy == IntervalStrategy.STEPS and self.logging_steps == 0:
             raise ValueError(f"logging strategy {self.logging_strategy} requires non-zero --logging_steps")
 
+        if self.logging_strategy == IntervalStrategy.STEPS and self.logging_steps > 1:
+            if self.logging_steps != int(self.logging_steps):
+                raise ValueError(f"--logging_steps must be an integer if bigger than 1: {self.logging_steps}")
+            self.logging_steps = int(self.logging_steps)
+        if self.evaluation_strategy == IntervalStrategy.STEPS and self.eval_steps > 1:
+            if self.eval_steps != int(self.eval_steps):
+                raise ValueError(f"--eval_steps must be an integer if bigger than 1: {self.eval_steps}")
+            self.eval_steps = int(self.eval_steps)
+        if self.save_strategy == IntervalStrategy.STEPS and self.save_steps > 1:
+            if self.save_steps != int(self.save_steps):
+                raise ValueError(f"--save_steps must be an integer if bigger than 1: {self.save_steps}")
+            self.save_steps = int(self.save_steps)
+
         # Sanity checks for load_best_model_at_end: we require save and eval strategies to be compatible.
         if self.load_best_model_at_end:
             if self.evaluation_strategy != self.save_strategy:
@@ -1194,6 +1234,20 @@ class TrainingArguments:
                     f"strategy: {self.evaluation_strategy}\n- Save strategy: {self.save_strategy}"
                 )
             if self.evaluation_strategy == IntervalStrategy.STEPS and self.save_steps % self.eval_steps != 0:
+                if self.eval_steps < 1 or self.save_steps < 1:
+                    if not (self.eval_steps < 1 and self.save_steps < 1):
+                        raise ValueError(
+                            "--load_best_model_at_end requires the saving steps to be a multiple of the evaluation "
+                            "steps, which cannot get guaranteed when mixing ratio and absolute steps for save_steps"
+                            f"{self.save_steps} and eval_steps {self.eval_steps}."
+                        )
+                    # Work around floating point precision issues
+                    LARGE_MULTIPLIER = 1_000_000
+                    if (self.save_steps * LARGE_MULTIPLIER) % (self.eval_steps * LARGE_MULTIPLIER) != 0:
+                        raise ValueError(
+                            "--load_best_model_at_end requires the saving steps to be a multiple of the evaluation "
+                            f"steps, but found {self.save_steps}, which is not a multiple of {self.eval_steps}."
+                        )
                 raise ValueError(
                     "--load_best_model_at_end requires the saving steps to be a round multiple of the evaluation "
                     f"steps, but found {self.save_steps}, which is not a round multiple of {self.eval_steps}."