add torch_gc to clear gpu cache in knowledge_based_chatglm.py

chatglm_llm.py

@@ -2,6 +2,19 @@ from langchain.llms.base import LLM
 from typing import Optional, List
 from langchain.llms.utils import enforce_stop_tokens
 from transformers import AutoTokenizer, AutoModel
+import torch
+
+DEVICE = "cuda"
+DEVICE_ID = "0"
+CUDA_DEVICE = f"{DEVICE}:{DEVICE_ID}" if DEVICE_ID else DEVICE
+
+
+def torch_gc():
+    if torch.cuda.is_available():
+        with torch.cuda.device(CUDA_DEVICE):
+            torch.cuda.empty_cache()
+            torch.cuda.ipc_collect()
+
 
 tokenizer = AutoTokenizer.from_pretrained(
     "THUDM/chatglm-6b",
@@ -15,6 +28,7 @@ model = (
     .cuda()
 )
 
+
 class ChatGLM(LLM):
     max_token: int = 10000
     temperature: float = 0.1