Feat: Add warmup_ratio (#893)

* Feat: Add warmup_ratio

* fix: update readme with more details on conflict

src/axolotl/core/trainer_builder.py

@@ -461,11 +461,14 @@ class HFCausalTrainerBuilder(TrainerBuilderBase):
         return AxolotlTrainer
 
     def build(self, total_num_steps):
-        warmup_steps = (
-            self.cfg.warmup_steps
-            if self.cfg.warmup_steps is not None
-            else min(int(0.03 * total_num_steps), 100)
-        )
+        warmup_steps = None
+        if self.cfg.warmup_steps is not None:
+            warmup_steps = self.cfg.warmup_steps
+        elif self.cfg.warmup_ratio is not None:
+            warmup_steps = max(int(self.cfg.warmup_ratio * total_num_steps), 0)
+        else:
+            warmup_steps = min(int(0.03 * total_num_steps), 100)
+
         logging_steps = (
             self.cfg.logging_steps
             if self.cfg.logging_steps is not None

src/axolotl/utils/config.py

@@ -372,6 +372,9 @@ def validate_config(cfg):
     if cfg.rope_scaling:
         LOG.warning("`rope_scaling` should now be be a key under `model_config`")
 
+    if cfg.warmup_steps and cfg.warmup_ratio:
+        raise ValueError("warmup_steps and warmup_ratio are mutually exclusive")
+
     # TODO
     # MPT 7b
     # https://github.com/facebookresearch/bitsandbytes/issues/25