发表机构
ETH Zurich; New York University（苏黎世联邦理工学院; 纽约大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出MORDOR弹性刷新调度策略，将预防性刷新从内存需求请求关键路径移出，在保障数据完整性的同时降低读取干扰缓解操作的性能与能耗开销，经评估可显著提升系统性能和能效。
AI 中文摘要
现代DRAM芯片易受RowHammer等读取干扰现象影响，反复访问（锤击）某一行DRAM单元（即DRAM行）会导致其他物理邻近的（受害）DRAM行发生位翻转。避免此类位翻转的常用方法是预防性刷新可能发生位翻转的受害行，但预防性刷新会导致较长延迟，且需在攻击者行再次激活前紧急执行以确保数据完整性，具体做法是将其优先级置于内存需求请求之上，这可能会给这些请求带来显著延迟，造成性能和能耗开销。本研究的目标是通过将预防性刷新调度从内存需求请求的关键路径上移开来缓解这些开销。我们提出了MORDOR，一种新型预防性刷新调度策略，可显著降低预防性刷新操作导致的系统性能下降和能耗。MORDOR集成于内存控制器中，与基于内存控制器的读取干扰缓解技术协同运行，可智能延迟预防性刷新操作，同时保持其数据完整性保证。MORDOR利用了一个关键观察结果：只要内存请求不访问攻击者行，针对该攻击者行的预防性刷新操作就可以延迟以服务任何其他内存需求请求。通过这种方式，MORDOR在缓解读取干扰位翻转的同时，在长延迟的预防性刷新操作之前执行延迟关键的内存请求。我们通过将MORDOR集成到六种最先进的读取干扰缓解技术中对其进行评估，综合评估表明，MORDOR以较低的面积成本显著提升了系统性能和能效。
英文摘要
Modern DRAM chips are susceptible to read disturbance phenomena such as RowHammer, where repeatedly accessing (hammering) a row of DRAM cells (i.e., a DRAM row) induces bitflips in other physically nearby (victim) DRAM rows. A common practice to avoid such bitflips is to preventively refresh victim rows that might otherwise experience bitflips. Unfortunately, preventive refreshes cause long latencies and need to be performed urgently before the aggressor row is activated again to ensure data integrity. This is done by prioritizing them over demand memory requests, thereby potentially imposing significant delays on those requests and causing performance and energy overheads. Our goal in this work is to alleviate these overheads by scheduling preventive refreshes off the critical path of demand memory requests. We propose MORDOR, a new preventive refresh scheduling policy that significantly reduces system performance degradation and energy consumption caused by preventive refresh operations. MORDOR is integrated into the memory controller and operates alongside memory-controller-based read disturbance mitigation techniques to intelligently delay preventive refresh operations, while maintaining their data integrity guarantees. MORDOR leverages the key observation that a preventive refresh operation targeting an aggressor row can be delayed to serve any other demand memory request, as long as that memory request does not access the aggressor row. By doing so, MORDOR executes latency-critical memory requests before long-latency preventive refresh operations, while mitigating read disturbance bitflips. We evaluate MORDOR by integrating it into six state-of-the-art read disturbance mitigation techniques. Our comprehensive evaluation shows that MORDOR significantly improves system performance and energy efficiency at low area cost.
Comments14 pages paper content, 20 pages with references and appendix, 14 figures, accepted at MICRO 2026
