Zallocator: A High Throughput Write-Optimized Persistent Allocator for Non-Volatile Memory

Abstract

Non-volatile main memory (NVRAM) is likely to break the bottleneck caused by data transferring between main memory and extern storage, and fundamentally change the way applications do data persistence. We can build persistent data structures directly on NVRAM. To do this correctly and efficiently, we need the support of persistent allocators guaranteeing failure-consistency. However, existing persistent allocators pay huge persistence overhead for failure-consistency. In this article, we present Zallocator, a write-optimized failure-consistency allocator for NVRAM. Zallocator hardly brings write operations to NVRAM. It keeps all the heap management metadata in DRAM, and rebuild them after a crash. Experimental results show that Zallocator achieves a throughput comparable to state-of-the-art transient allocators, and reduces the average number of NVRAM writes per allocation/deallocation to almost zero.