Flash conversion layer control method based on request classification

Abstract

The present invention discloses a flash conversion layer control method based on request classification. The method comprises the following steps: Step S1: setting a plurality of address mapping cachetables in a memory according to an operation request of the file system and an address request frequency; Step S2: obtaining the operation request of the file system in the flash conversion layer andparsing the operation request to determine the operation request type; Step S3: searching the logical page address of the operation request in multiple address mapping cache tables in different priority orders according to the operation request type until hitting the corresponding address mapping entry; and Step S4: updating the memory address mapping cache tables according to the operation request result. Compared with the prior art, according to the method disclosed by the present invention, the request is divided in a more fine-grained manner, quickly hitting the mapping entry is facilitated, and when removing the mapping entry, the classified removal can be carried out to accelerate the removal speed, the mapping entries that must be updated can be quickly sorted, and the update of the mapping entries that does not require to be updated is avoided.

Description

technical field [0001] The invention relates to the field of storage technology, in particular to a method for controlling a flash conversion layer based on request classification for solid-state storage devices. Background technique [0002] With the continuous popularization of computers and networks, people have higher and higher requirements on the speed of computers, and a key factor restricting the speed of computers is the speed of storage media. The large-capacity storage medium of traditional personal computers is a mechanical hard disk, but due to its mechanical rotating structure, its read and write speed is very limited and its shock resistance is not good. Compared with HDD (Hard Disk Drive), SSD has the advantages of fast read and write speed, good shock resistance, and low power consumption. At present, common SSDs are mainly based on NAND flash, and the physical structure of NAND flash is different from traditional magnetic storage media. The main difference...

AI Technical Summary

Problems solved by technology

2) When the page is not an empty page, the flash memory cannot overwrite the page. It is necessary to erase the block where the page is located before writing data to this page.

4) The erasing times of the flash memory are limited, and after reaching a certain number, it will become a bad block and cannot be used anymore

[0005] However, the CMT in DFTL only considers the time locality of the request, and does not consider the spatial locality of the request, which reduces the hit rate of the cache.

In addition, the elimination strategy of CMT's LRU single mapping item may trigger frequent update operations and garbage collection operations of conversion pages. Reduced system speed and lifespan

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