ACCESS-BASED EVICTION OF BLOCKS FROM SOLID STATE DRIVE CACHE MEMORY

摘要

Methods and systems are presented for allocating CPU cycles among processes in a storage system. One method includes operations for maintaining segments in a first memory, each segment including blocks, and for maintaining a block temperature for each block in a second memory. The first memory is a read-cache where one segment is written at a time, and each block is readable from the first memory without reading the corresponding complete segment. The block temperature is based on the frequency of access to the respective block, and a segment temperature is based on the block temperature of its blocks. Additionally, the segment with the lowest segment temperature is selected for eviction from the second memory, and blocks in the selected segment with a block temperature greater than a threshold temperature are identified. The selected segment is evicted, and a segment with the identified blocks is written to the first memory.

主权项

1. A method comprising:
maintaining, in a first memory, a plurality of segments, each segment including a plurality of blocks, and maintaining, in a second memory, a block temperature for each of a plurality of blocks, wherein the first memory is a read-cache memory where one segment is written at a time, wherein each block is readable from the first memory without reading the corresponding complete segment, each block temperature being based on a frequency of access to the respective block, wherein a segment temperature for each segment is based on the block temperature for the corresponding plurality of blocks within the segment; selecting a segment from a plurality of segments with a lowest segment temperature for eviction from the second memory; identifying blocks in the selected segment with a block temperature greater than a threshold temperature; evicting the selected segment from the first memory; and writing to the first memory a new segment having the identified blocks.