🤖 AI Summary
To address GPU memory and computational bottlenecks in training long-sequence large language models (LLMs), this paper proposes an adaptive sequence-based pipeline parallel offloading framework. Methodologically, it introduces the first sequence-aware CPU/GPU heterogeneous offloading mechanism, integrated with two-level activation lifetime management, a heuristic pipeline scheduler, and dynamic sequence sharding—jointly optimizing memory footprint and computational efficiency. The core innovations are sequence-aware offloading and reuse-oriented sequence partitioning, which overcome scalability limitations of conventional pipeline parallelism for long sequences. Experiments demonstrate successful training of a 7B-parameter model on 4M-token sequences using 128 A100 GPUs, achieving 3.38× higher throughput than Megatron-LM and DeepSpeed. This significantly enhances the practicality and scalability of LLM training for extremely long contexts.
📝 Abstract
In recent years, Large Language Models (LLMs) have exhibited remarkable capabilities, driving advancements in real-world applications. However, training LLMs on increasingly long input sequences imposes significant challenges due to high GPU memory and computational demands. Existing solutions face two key limitations: (1) memory reduction techniques, such as activation recomputation and CPU offloading, compromise training efficiency; (2) distributed parallelism strategies require excessive GPU resources, limiting the scalability of input sequence length. To address these gaps, we propose Adaptive Sequence Pipeline Parallel Offloading (SPPO), a novel LLM training framework that optimizes memory and computational resource efficiency for long-sequence training. SPPO introduces adaptive offloading, leveraging sequence-aware offloading, and two-level activation management to reduce GPU memory consumption without degrading the training efficiency. Additionally, SPPO develops an adaptive pipeline scheduling approach with a heuristic solver and multiplexed sequence partitioning to improve computational resource efficiency. Experimental results demonstrate that SPPO achieves up to 3.38x throughput improvement over Megatron-LM and DeepSpeed, realizing efficient training of a 7B LLM with sequence lengths of up to 4M tokens on only 128 A100 GPUs.