Multi-channel dynamic read-write dispatching method used in solid state drive (SSD)

Abstract

The invention discloses a multi-channel dynamic read-write dispatching method used in solid state drive (SSD). According to the method, a target-passage of write-request is selected according to a rotating dispatching strategy. A read-request sequence of the target-passage is recorded. The write-request delivered by a main machine end is buffered on a write-buffer of the SSD. The read-request sequence of the target-passage is analyzed when the accumulation of data quantity of the write-buffer reaches the designated threshold value. Hot-point data are found. The hot-point data are pre-taken to the write-buffer, thus the hit rate of the read-request is improved. The write-request accumulated by the write-buffer is dispatched to the target-passage and the write-request is carried out. Read-request of line-up wait responds when the write-request is carried out at the same time. At last, the accumulated write-request is completed by carrying out. The multi-channel dynamic read-write dispatching method used in the SSD has the advantages of being balanced in writing of each passage, long in service life of the SSD, small in influence of the write-request to the read-request, small in influence of rubbish recycling to the read-request, and low in read-delay.

Description

technical field [0001] The invention relates to a read-write scheduling method inside an SSD (solid state disk), in particular to a multi-channel dynamic read-write scheduling method for an SSD. Background technique [0002] A flash-based SSD (Solid State Drive, solid state disk) is a new type of mass storage device. The basic read / write unit of flash memory is page. If a page already contains a piece of data, when the data needs to be updated, new data cannot be written directly to the page, because the page that already contains data can only be written again after being erased (Erase). . The erase operation delay is very large, and the basic unit of the erase operation is a block (Block), a block contains 2 i (64 or 128) pages, the entire block cannot be erased because of the modification of a page of data. Therefore, for data update in SSD, the usual practice is to write the updated data to a new page, and how to select a new page depends on the write scheduling stra...

AI Technical Summary

Problems solved by technology

Due to the high latency of write operations, and the application on the host side is waiting for the data of the read request, blocking the read request will significantly increase the waiting time of the application

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