libhashckpt: Hash-Based Incremental Checkpointing Using GPU's

Concern is beginning to grow in the high-performance computing (HPC) community regarding the reliability guarantees of future large-scale systems. Disk-based coordinated checkpoint/restart has been the dominant fault tolerance mechanism in HPC systems for the last 30 years. Checkpoint performance is so fundamental to scalability that nearly all capability applications have custom checkpoint strategies to minimize state and reduce checkpoint time. One well-known optimization to traditional checkpoint/restart is incremental checkpointing, which has a number of known limitations. To address these limitations, we introduce libhashckpt; a hybrid incremental checkpointing solution that uses both page protection and hashing on GPUs to determine changes in application data with very low overhead. Using real capability workloads, we show the merit of this technique for a certain class of HPC applications.