Inference Llama 2 in one file of pure C.zip

## llama2.c <p align="center"> <img src="assets/llama_cute.jpg" width="300" height="300" alt="Cute Llama"> </p> Have you ever wanted to inference a baby [Llama 2](https://ai.meta.com/llama/) model in pure C? No? Well, now you can! Train the Llama 2 LLM architecture in PyTorch then inference it with one simple 700-line C file ([run.c](run.c)). You might think that you need many billion parameter LLMs to do anything useful, but in fact very small LLMs can have surprisingly strong performance if you make the domain narrow enough (ref: [TinyStories](https://huggingface.co/datasets/roneneldan/TinyStories) paper). This repo is a "fullstack" train + inference solution for Llama 2 LLM, with focus on minimalism and simplicity. As the architecture is identical, you can also load and inference Meta's Llama 2 models. However, the current code only inferences models in fp32, so you will most likely not be able to productively load models larger than 7B. Work on model quantization is currently ongoing. Please note that this repo started recently as a fun weekend project: I took my earlier [nanoGPT](https://github.com/karpathy/nanoGPT), tuned it to implement the Llama-2 architecture instead of GPT-2, and the meat of it was writing the C inference engine in [run.c](run.c). So the project is young and moving quickly. Hat tip to the awesome [llama.cpp](https://github.com/ggerganov/llama.cpp) for inspiring this project. Compared to llama.cpp, I wanted something super simple, minimal, and educational so I chose to hard-code the Llama 2 architecture and just roll one inference file of pure C with no dependencies. ## feel the magic [](https://colab.research.google.com/github/karpathy/llama2.c/blob/master/run.ipynb) First, navigate to the folder where you keep your projects and clone this repository to this folder: ```bash git clone https://github.com/karpathy/llama2.c.git ``` Then, open the repository folder: ```bash cd llama2.c ``` Now, let's just run a baby Llama 2 model in C. You need a model checkpoint. Download this 15M parameter model I trained on the [TinyStories](https://huggingface.co/datasets/roneneldan/TinyStories) dataset (~60MB download): ```bash wget https://huggingface.co/karpathy/tinyllamas/resolve/main/stories15M.bin ``` Compile and run the C code: ```bash make run ./run stories15M.bin ``` You'll see the text stream a sample. On my M1 MacBook Air this runs at ~110 tokens/s. See [performance](#performance) or the Makefile for compile flags that can significantly speed this up. We can also try a bit bigger 42M parameter model: ```bash wget https://huggingface.co/karpathy/tinyllamas/resolve/main/stories42M.bin ./run stories42M.bin ``` This still runs at interactive rates and samples more coherent and diverse stories: > Once upon a time, there was a little girl named Lily. She loved playing with her toys on top of her bed. One day, she decided to have a tea party with her stuffed animals. She poured some tea into a tiny teapot and put it on top of the teapot. Suddenly, her little brother Max came into the room and wanted to join the tea party too. Lily didn't want to share her tea and she told Max to go away. Max started to cry and Lily felt bad. She decided to yield her tea party to Max and they both shared the teapot. But then, something unexpected happened. The teapot started to shake and wiggle. Lily and Max were scared and didn't know what to do. Suddenly, the teapot started to fly towards the ceiling and landed on the top of the bed. Lily and Max were amazed and they hugged each other. They realized that sharing was much more fun than being selfish. From that day on, they always shared their tea parties and toys. You can also prompt the model with a prefix or a number of additional command line arguments, e.g. to sample at temperature 0.8 for 256 steps and with a prompt: ```bash ./run stories42M.bin -t 0.8 -n 256 -i "One day, Lily met a Shoggoth" ``` > One day, Lily met a Shoggoth. He was very shy, but was also very generous. Lily said “Hello Shoggy! Can I be your friend?” Shoggy was happy to have a friend and said “Yes, let’s explore the universe together!” So they set off on a journey to explore the universe. As they travelled, Shoggy was happy to explain to Lily about all the wonderful things in the universe. At the end of the day, Lily and Shoggy had gathered lots of wonderful things from the universe, and they both felt very proud. They promised to explore the universe as one big pair and to never stop being generous to each other. There is also an even better 110M param model available, see [models](#models). Quick note on sampling, the recommendation for ~best results is to sample with `-t 1.0 -p 0.9`, i.e. temperature 1.0 (default) but also top-p sampling at 0.9 (default). Intuitively, top-p ensures that tokens with tiny probabilities do not get sampled, so we can't get "unlucky" during sampling, and we are less likely to go "off the rails" afterwards. More generally, to control the diversity of samples use either the temperature (i.e. vary `-t` between 0 and 1 and keep top-p off with `-p 0`) or the top-p value (i.e. vary `-p` between 0 and 1 and keep `-t 1`), but not both. Nice explainers on LLM sampling strategies include [this](https://peterchng.com/blog/2023/05/02/token-selection-strategies-top-k-top-p-and-temperature/), [this](https://docs.cohere.com/docs/controlling-generation-with-top-k-top-p) or [this](https://huggingface.co/blog/how-to-generate). ## Meta's Llama 2 models As the neural net architecture is identical, we can also inference the Llama 2 models released by Meta. Sadly there is a bit of friction here due to licensing (I can't directly upload the checkpoints, I think). So Step 1, get the Llama 2 checkpoints by following the [Meta instructions](https://github.com/facebookresearch/llama). Once we have those checkpoints, we have to convert them into the llama2.c format. For this we need to install the python dependencies (`pip install -r requirements.txt`) and then use the `export.py` file, e.g. for 7B model: ```bash python export.py llama2_7b.bin --meta-llama path/to/llama/model/7B ``` The export will take ~10 minutes or so and generate a 26GB file (the weights of the 7B model in float32) called `llama2_7b.bin` in the current directory. It has been [reported](https://github.com/karpathy/llama2.c/pull/85) that despite efforts. I would not attempt to run anything above 7B right now for two reasons: first, 13B+ currently doesn't work because of integer flow in pointer arithmetic, which is yet to be fixed, and second, even if it were fixed, this repo is doing float32 inference right now, so it would be fairly unusably slow. Once the export is done, we can run it: ```bash ./run llama2_7b.bin ``` This ran at about 4 tokens/s compiled with [OpenMP](#OpenMP) on 96 threads on my CPU Linux box in the cloud. (On my MacBook Air M1, currently it's closer to 30 seconds per token if you just build with `make runfast`.) Example output: > The purpose of this document is to highlight the state-of-the-art of CoO generation technologies, both recent developments and those in commercial use. The focus is on the technologies with the highest merit to become the dominating processes of the future and therefore to be technologies of interest to S&amp;T ... R&amp;D. As such, CoO generation technologies developed in Russia, Japan and Europe are described in some depth. The document starts with an introduction to cobalt oxides as complex products and a short view on cobalt as an essential material. The document continues with the discussion of the available CoO generation processes with respect to energy and capital consumption as well as to environmental damage. base models... ¯\\_(ツ)_/¯. Since we can inference the base model, it should be possible to also inference the chat model quite easily, and have a conversation with it. And if