gradient accumulation tests, embeddings w pad_token fix, smaller models (#2059)

* add more test cases for gradient accumulation and fix zero3

* swap out for smaller model

* fix missing return

* fix missing pad_token in config

* support concurrency for multigpu testing

* cast empty deepspeed to empty string for zero3 check

* fix temp_dir as fixture so parametrize works properly

* fix test file for multigpu evals

* don't use default

* don't use default for fsdp_state_dict_type

* don't use llama tokenizer w smollm

* also automatically cancel multigpu for concurrency

tests/e2e/multigpu/test_qwen2.py

@@ -4,31 +4,30 @@ E2E tests for multigpu qwen2
 
 import logging
 import os
-import unittest
 from pathlib import Path
 
+import pytest
 import yaml
 from accelerate.test_utils import execute_subprocess_async
+from transformers.testing_utils import get_torch_dist_unique_port
 
 from axolotl.utils.dict import DictDefault
 
-from ..utils import with_temp_dir
-
 LOG = logging.getLogger("axolotl.tests.e2e.multigpu")
 os.environ["WANDB_DISABLED"] = "true"
 
 
-class TestMultiGPUQwen2(unittest.TestCase):
+class TestMultiGPUQwen2:
     """
     Test case for Llama models using LoRA
     """
 
-    @with_temp_dir
-    def test_qlora_fsdp_dpo(self, temp_dir):
+    @pytest.mark.parametrize("base_model", ["Qwen/Qwen2-0.5B", "Qwen/Qwen2.5-0.5B"])
+    def test_qlora_fsdp_dpo(self, base_model, temp_dir):
         # pylint: disable=duplicate-code
         cfg = DictDefault(
             {
-                "base_model": "Qwen/Qwen2-1.5B",
+                "base_model": base_model,
                 "load_in_4bit": True,
                 "rl": "dpo",
                 "chat_template": "chatml",
@@ -47,9 +46,9 @@ class TestMultiGPUQwen2(unittest.TestCase):
                     },
                 ],
                 "num_epochs": 1,
-                "max_steps": 15,
+                "max_steps": 5,
                 "warmup_steps": 20,
-                "micro_batch_size": 4,
+                "micro_batch_size": 2,
                 "gradient_accumulation_steps": 2,
                 "output_dir": temp_dir,
                 "learning_rate": 0.00001,
@@ -91,6 +90,8 @@ class TestMultiGPUQwen2(unittest.TestCase):
                 "launch",
                 "--num-processes",
                 "2",
+                "--main_process_port",
+                f"{get_torch_dist_unique_port()}",
                 "-m",
                 "axolotl.cli.train",
                 str(Path(temp_dir) / "config.yaml"),