Hierarchical FTL Mapping Optimized for Workload

摘要

In a memory system having non-volatile memory and volatile memory, write data are stored in a write-coalescing buffer in the volatile memory until the write data is written to non-volatile memory. First and second level address mapping tables are stored in the volatile memory and corresponding first and second level address mapping tables are stored in the non-volatile memory, and furthermore the second level address mapping table in the volatile memory contains entries corresponding to only a subset of the entries in the second level address mapping table in the non-volatile memory. The first address-mapping table in volatile memory includes entries storing pointers to entries in the second address-mapping table in volatile memory, entries storing pointers to locations in the write-coalescing buffer, and entries storing pointers to locations in the non-volatile memory that store data.

主权项

1. A method of performing address mapping, the method comprising:
in a memory system comprising non-volatile memory and volatile memory:
storing write data in a write-coalescing buffer in the volatile memory;in accordance with satisfaction of a condition, moving the write data from the write-coalescing buffer to the non-volatile memory and freeing space in the write-coalescing buffer; andmaintaining a first address-mapping table and a second address-mapping table in the volatile memory, wherein:
the first address-mapping table includes entries storing pointers to entries in the second address-mapping table, entries storing pointers to locations in the write-coalescing buffer, and entries storing pointers to locations in the non-volatile memory that store data; andthe second address-mapping table includes entries storing pointers to locations in the write-coalescing buffer and entries storing pointers to locations in the non-volatile memory that store data.