app.py

import streamlit as st
from langchain.chains import LLMChain
from langchain.prompts import PromptTemplate
import torch,os
from langchain.llms import HuggingFacePipeline
from transformers import AutoTokenizer,AutoModelForCausalLM,pipeline,BitsAndBytesConfig

model_name_or_path = "meta-llama/Llama-2-13b-chat-hf"

# Count the number of GPUs available
gpu_count = torch.cuda.device_count()

# Determine the device to use based on GPU availability and count
# If more than one GPU is available, use 'auto' to allow the library to choose
# If only one GPU is available, use 'cuda:0' to specify the first GPU
# If no GPU is available, use the CPU
if torch.cuda.is_available() and gpu_count > 1:
    device = 'auto'
elif torch.cuda.is_available():
    device = 'cuda:0'
else:
    device = 'cpu'

tokenizer = AutoTokenizer.from_pretrained(model_name_or_path)
model = AutoModelForCausalLM.from_pretrained(model_name_or_path,
                                            #  quantization_config=bnb_config,
                                             torch_dtype=torch.float16,
                                             device_map='auto',)
print(model.hf_device_map)

pipe = pipeline(
    "text-generation",
    model=model,
    tokenizer=tokenizer,
    max_length=2500,
    return_full_text=True,
    do_sample=True,
    repetition_penalty=1.15,
    num_return_sequences=1,
    pad_token_id=2,
    model_kwargs={"temperature": 0.3,
                                  "top_p":0.95,
                                  "top_k":40,
                                  "max_new_tokens":2500},
)
llm = HuggingFacePipeline(pipeline=pipe)
template = template = """Prompt: {query}
Answer: """

prompt_template = PromptTemplate(
    input_variables=["query"],
    template=template
)
#instantiate the chain
llm_chain = LLMChain(prompt=prompt_template, llm=llm)

st.title('Test Multi GPU')

md = st.text_area('Type in your markdown string (without outer quotes)')

st.button("Enter", type="primary")
if st.button("Say hello"):
    resp=llm_chain.invoke(md)['text']
    st.write(resp)
else:
    st.write("Goodbye")