LiNoVo: Longevity Enhancement of Non-Volatile Last Level Caches in Chip Multiprocessors

The evolution of Non-Volatile Memories (NVM) draws the attention of computer architects to look beyond conventional memory technologies in the memory hierarchy. The benefits offered by these NVMs are high density, good scalability, and low static power consumption. However, such NVM caches suffer from costly write operations and weak write endurance. This paper proposed four longevity enhancement approaches for the NVM cache. Our first policy allocates a dataless entry for the private blocks to reduce the costly write operations in the NVM based hybrid caches. The second approach improves the performance of NVM caches by employing the optimized victim cache. Whereas the other two proposals focus on improving the lifetime variability due to the write variation present inside the cache bank. The experiment evaluation with all the proposed approaches shows significant longevity of NVM caches over different metrics.