通过预测管理提升大模型加速器共享缓存性能,实现1.8倍提速。
DCO: Dynamic Cache Orchestration for LLM Accelerators through Predictive Management
- 利用软件数据流信息预测缓存替换和无效块,动态调度
- 相比传统架构最高提速1.80倍,支持多核共享与无共享场景
- 设计面积仅0.064mm²,15nm工艺下可运行于2GHz,适合部署
大型语言模型的快速普及推动了AI加速器向更强大、专用化方向发展。我们探索相反的设计路径:采用多核AI加速器配备共享系统级缓存,并结合应用感知管理策略,在保持编程开销适中的同时提升性能。该方法利用软件栈中可用的数据流信息,指导缓存替换(包括无效块预测),并协同旁路决策与缓存抖动缓解机制。通过周期精确仿真评估,相比传统缓存架构获得高达1.80倍的性能提升。此外,我们构建了分析模型,考虑实际任务重叠行为,将策略效果外推至更大规模真实负载。实验表明,旁路与抖动缓解策略协同工作,能有效应对有/无核间数据共享场景,实现显著加速。最终在RTL层面实现该设计,基于15nm工艺,面积为0.064mm²,可在2GHz频率下运行。研究揭示了共享缓存设计在下一代AI加速器中的潜力。
原文摘要 · Abstract (English)
The rapid adoption of large language models (LLMs) is pushing AI accelerators toward increasingly powerful and specialized designs. Instead of further complicating software development with deeply hierarchical scratchpad memories (SPMs) and their asynchronous management, we investigate the opposite point of the design spectrum: a multi-core AI accelerator equipped with a shared system-level cache and application-aware management policies, which keeps the programming effort modest. Our approach exploits dataflow information available in the software stack to guide cache replacement (including dead-block prediction), in concert with bypass decisions and mechanisms that alleviate cache thrashing. We assess the proposal using a cycle-accurate simulator and observe substantial performance gains (up to 1.80x speedup) compared with conventional cache architectures. In addition, we build and validate an analytical model that takes into account the actual overlapping behaviors to extend the measurement results of our policies to real-world larger-scale workloads. Experiment results show that when functioning together, our bypassing and thrashing mitigation strategies can handle scenarios both with and without inter-core data sharing and achieve remarkable speedups. Finally, we implement the design in RTL and the area of our design is $\mathbf{0.064mm^2}$ with 15nm process, which can run at 2 GHz clock frequency. Our findings explore the potential of the shared cache design to assist the development of future AI accelerator systems.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。