System and methods for prioritizing data in a cache

Abstract

Implementations described and claimed herein provide a system and methods for prioritizing data in a cache. In one implementation, a priority level, such as critical, high, and normal, is assigned to cached data. The priority level dictates how long the data is cached and consequently, the order in which the data is evicted from the cache memory. Data assigned a priority level of critical will be resident in cache memory unless heavy memory pressure causes the system to reclaim memory and all data assigned a priority state of high or normal has been evicted. High priority data is cached longer than normal priority data, with normal priority data being evicted first. Accordingly, important data assigned a priority level of critical, such as a deduplication table, is kept resident in cache memory at the expense of other data, regardless of the frequency or recency of use of the data.