patch cog to fix issue with transformers

utils/patch_cog.py

@@ -0,0 +1,27 @@
+from typing import Any, Dict
+import torch
+import bitsandbytes as bnb
+from transformers.quantizers.quantizer_bnb_4bit import Bnb4BitHfQuantizer, get_module_from_name
+from transformers.modeling_utils import PreTrainedModel
+
+# CogVLM stores inv_freq in the state dictionary but it is not in models._parameters so it cannot be quantized
+# was patched in transformers for other models here: https://github.com/huggingface/transformers/pull/28837/files but cog is not part of transformers
+def _patched_check_quantized_param(
+        self, model: "PreTrainedModel", param_value: "torch.Tensor", param_name: str, state_dict: Dict[str, Any]
+    ) -> bool:
+
+    # if "inv_freq" in param_name:  # detect failure case
+    #     print("check_quantized_param", param_name)
+
+    module, tensor_name = get_module_from_name(model, param_name)
+    if ("inv_freq" == tensor_name): # the fix
+        return False
+    if isinstance(module._parameters[tensor_name], bnb.nn.Params4bit): # will throw key error for inv_freq
+        return True
+    elif isinstance(module, bnb.nn.Linear4bit) and tensor_name == "bias":
+        return True
+    else:
+        return False
+
+def patch_cog():
+    Bnb4BitHfQuantizer.check_quantized_param = _patched_check_quantized_param