LLoCO: Learning Long Contexts Offline

Processing long contexts remains a challenge for large language models (LLMs) due to the quadratic computational and memory overhead of the self-attention mechanism and the substantial KV cache sizes during generation. We propose LLoCO, a novel approach to address this problem by learning contexts offline through context compression and in-domain parameter-efficient finetuning with LoRA. Our method enables an LLM to create a concise representation of the original context and efficiently retrieve relevant information to answer questions accurately. Our approach extends the effective context window of a 4k token LLaMA2-7B model to handle up to 128k tokens. We evaluate our approach on several longcontext question-answering datasets, demonstrating that LLoCO significantly outperforms in-context learning while using 30× fewer tokens during inference. LLoCO achieves up to 7.62× speed-up during inference and 11.52× higher throughput during finetuning, substantially reduces the cost of long document question answering. This makes it a promising solution for efficient long context processing. 1 * Equal contribution 1 Our code is publicly available on https://github.com/ jeffreysijuntan/lloco .