Method for improving density of mapping information in address mapping table

Abstract

The invention discloses a method for improving the density of mapping information in an address mapping table. A hit rate of a cache mapping table in a page mapping scheme on the basis of the mapping information of a cache part can be improved; the read-write performance of a flash translation layer is improved; on a premise that the amount of entries in the cache mapping table positioned in a memory is not increased, mapping records which are continuous and adjacent on a logic address and a physical address are combined to generate one mapping entry, and therefore, one mapping entry can express a mapping relationship between a plurality of logic addresses and the physical address; and one mapping entry, instead of a plurality of mapping records which only can express the mapping relationship between one logic address and the physical address, is inserted into the cache mapping table. Therefore, on the premise that occupation for the memory by the cache mapping table is not increased, the amount of mapping records stored in the cache mapping table is increased, the hit rate of the cache mapping table can be obviously improved, the read-write efficiency of the flash translation layer is improved, and the method can be widely applied to the management of the NAND Flash memories of various systems.

Description

technical field [0001] The invention relates to the technical field of data storage, in particular to a method for increasing the density of mapping information in an address mapping table. Background technique [0002] NAND Flash is a non-volatile semiconductor memory, and the data stored on it will not be lost due to power failure. Since there are no mechanical parts inside the NAND Flash memory, it has low power consumption, low heat generation, and low weight. Lightweight, small size, good shock resistance and other advantages that traditional mechanical disk storage does not have, and its random read and write performance is much higher than traditional mechanical disk storage. With the breakthrough of flash storage capacity bottleneck, performance optimization and cost reduction, NAND Flash memory has become a very important digital storage medium. [0003] NAND Flash is composed of many blocks (Block), and each block is composed of several pages (Page), where a page ...

AI Technical Summary

Problems solved by technology

However, because the cache mapping table can only store limited mapping records, some requests cannot hit the cache mapping table and cannot complete direct addressing, and need to exchange mapping records with the mapping table in NAND Flash, resulting in non-requests that lead to reading NAND Flash The additional read operation of the above mapping table and the additional write operation of writing the mapping record to the NAND Flash, and the writing of the mapping record to the NAND Flash will also generate additional garbage collection operations due to insufficient free blocks

These additional frictions eventually lead to lower performance than page mapping, and the lower the hit rate, the worse the performance

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