fix: clean up data, pad at end

configs/train/finetune_gptj.yaml

@@ -0,0 +1,33 @@
+# model/tokenizer
+model_name: "EleutherAI/gpt-j-6B"
+tokenizer_name: "EleutherAI/gpt-j-6B"
+gradient_checkpointing: true
+save_name: "nomic-ai/gpt4all-gptj-multiturn-lr-aggressive"
+
+# dataset
+streaming: false
+num_proc: 64
+dataset_path: "data_multiplus" 
+max_length: 1024
+batch_size: 8
+
+# train dynamics
+lr: 2.0e-5
+min_lr: 0 
+weight_decay: 0.0
+eval_every: 200
+eval_steps: 105
+save_every: 400
+log_grads_every: 200
+output_dir: "ckpts/gpt4all-gptj-full-multiturn-lr-aggreive"
+checkpoint: null
+lora: false
+warmup_steps: 500
+num_epochs: 4 
+
+# logging
+wandb: true
+wandb_entity: vicuna
+wandb_project_name: vicuna
+seed: 42
+

data.py

@@ -11,42 +11,38 @@ def tokenize_inputs(config, tokenizer, examples):
     max_length = config["max_length"]
     input_ids = torch.full((len(examples["prompt"]), max_length), tokenizer.pad_token_id)
     # ignore bos
-    newline_tokens = tokenizer("\n", return_tensors="pt")["input_ids"][0, 1:]
+    newline_tokens = tokenizer("\n", return_tensors="pt")["input_ids"][0]
+    if newline_tokens[0] == tokenizer.bos_token_id:
+        newline_tokens = newline_tokens[1:]
 
-    out = {"labels": [], "attention_mask": []}
-    for i, (prompt, response) in enumerate(zip(examples["prompt"], examples["response"])):
-        input_tokens = tokenizer(prompt, truncation=True, max_length=max_length // 2, return_tensors="pt")["input_ids"].squeeze()
-        input_len = len(input_tokens)
+    # hacky backward compatible
+    different_eos = tokenizer.eos_token != "</s>"
+    out = {"labels": [], "input_ids": []}
+    for prompt, response in zip(examples["prompt"], examples["response"]):
+        if different_eos:
+            if response.count("</s>") > 0:
+                response = response.replace("</s>", tokenizer.eos_token)
 
-        # plus one since we remove bos from response
-        # but we subtract one since we want to add eos token
-        remaining_tokens = max_length - input_len - len(newline_tokens) + 1
-        # remove bos
-        target_tokens = tokenizer(response, truncation=True, max_length=remaining_tokens, return_tensors="pt")["input_ids"].squeeze()[1:]
+        prompt_len = len(tokenizer(prompt, truncation=True, return_tensors="pt")["input_ids"][0])
 
-        input_ids[i, :input_len] = input_tokens
-        # add newline between prompt and response
-        newline_plus_inputs = input_len + len(newline_tokens)
-        input_ids[i, input_len: newline_plus_inputs] = newline_tokens
+        # hack if our prompt is super long
+        # we need to include some labels
+        if prompt_len >= max_length - 1:
+            prompt = prompt[:len(prompt) // 2]
 
-        # add target tokens, remove bos
-        input_ids[i, newline_plus_inputs: newline_plus_inputs + len(target_tokens)] = target_tokens
-        # add eos token, enforce stopping if we don't truncate 
-        # we don't want long code to stop generating if truncated during training
-        if newline_plus_inputs + len(target_tokens) < max_length:
-            input_ids[i, newline_plus_inputs + len(target_tokens)] = tokenizer.eos_token_id
+        input_tokens = tokenizer(prompt + "\n" + response + tokenizer.eos_token,
+                                 truncation=True, max_length=max_length, return_tensors="pt")["input_ids"].squeeze()
 
-        labels = input_ids[i].clone()
-        labels[: newline_plus_inputs] = -100
-        labels[labels == tokenizer.pad_token_id] = -100
-        # to debug this, can set all values == -100 to the pad token, then assert that tokenizer.decode(labels, skip_special_tokens=True).strip() == response
 
-        attention_mask = input_ids[i].ne(tokenizer.pad_token_id).int()
+        labels = input_tokens.clone()
+        labels[:prompt_len + len(newline_tokens)] = -100
+        if len(labels) < max_length:
+            # pad to max_length with -100
+            labels = torch.cat([labels, torch.full((max_length - len(labels),), -100)])
 
+        input_tokens = tokenizer.pad({"input_ids": input_tokens}, padding="max_length", max_length=max_length)["input_ids"]
         out["labels"].append(labels)
-        out["attention_mask"].append(attention_mask)
-
-    out["input_ids"] = input_ids
+        out["input_ids"].append(input_tokens)
 
     out = {k: torch.stack(v) if isinstance(v, list) else v for k, v in out.items()}