Garbage collection based on the inactivity level of stored data

摘要

A data storage system implements garbage collection based on the inactivity level of stored data. In one embodiment, the inactivity level of data stored in regions of a data storage system is taken into account when prioritizing regions for garbage collection. Inactivity level of memory regions can be compared to an inactivity threshold. The threshold can be adjusted during operation of the data storage system. Garbage collection can be delayed until data stored in a particular region is unlikely to be updated. Write amplification associated with garbage collection is reduced, and improved performance is attained.

主权项

1. A non-volatile data storage system, comprising:
a data storage module comprising a plurality of regions for storing data; and a controller configured to:
compute a set of scores associated with a set of regions of the plurality of regions, each score based at least in part on a duration since last invalidation of data stored in a corresponding region; andperform garbage collection of at least one region based at least partly on the set of scores, wherein garbage collection comprises copying valid data stored in the at least one region to another region.