CN111324303A

CN111324303A - SSD garbage recycling method and device, computer equipment and storage medium

Info

Publication number: CN111324303A
Application number: CN202010068514.6A
Authority: CN
Inventors: 尹子航; 肖蔓君; 陶英林
Original assignee: Shenzhen Union Memory Information System Co Ltd
Current assignee: Shenzhen Union Memory Information System Co Ltd
Priority date: 2020-01-21
Filing date: 2020-01-21
Publication date: 2020-06-23
Anticipated expiration: 2040-01-21
Also published as: CN111324303B

Abstract

The invention relates to a method and a device for recovering SSD garbage, computer equipment and a storage medium; the method comprises the following steps: selecting a sacrifice block, and reading data to be moved; judging whether the data to be moved is cold data or hot data; if the data is cold data, sorting the blocks according to the size of the erasing times, forming a moving maximum group with all the blocks of which the difference value with the erasing times of the current maximum erasing times is smaller than K, selecting the block with the longest operation time in the moving maximum group as a target block, erasing the target block, and moving the cold data to be moved to the target block; if the data is hot data, sorting the blocks according to the size of the erasing times, forming a moving minimum group with all the blocks of which the difference value of the erasing times with the current minimum erasing time block is smaller than M, selecting the block with the shortest operation time in the moving minimum group as a target block, erasing the target block, and moving the hot data to be moved to the target block. The invention can effectively prolong the whole service life and performance of the SSD.

Description

SSD garbage recycling method and device, computer equipment and storage medium

Technical Field

The invention relates to the technical field of solid state disk garbage recovery, in particular to an SSD garbage recovery method, an SSD garbage recovery device, computer equipment and a storage medium.

Background

In the existing target block selection strategy for SSD (solid state disk) Garbage Collection (GC), a general method is to perform target block management according to the size of the number of times of Erasing (EC) of an idle block, and when a GC operates to apply for a target block, a block with the minimum current EC is preferentially allocated as the target block; the method has the disadvantages that the reference factor of target Block selection is too single, different types of data are not specially processed, such as GC operation is carried out on 'cold data', the applied target Block is the Block with the minimum EC currently, and the 'cold data' can not be accessed for a long period of time in the future, so that the waste of resources is caused, the whole service life of the SSD is influenced, in addition, the method does not fully consider the physical characteristics of NAND, the operation time (read-write-erase) of each Block (Block) is different, and compared with the target Block with long operation time and the target Block with short operation time allocated to 'hot data', the whole performance of the SSD is inevitably improved by allocating the 'hot data' to the target Block with short operation time in the long term; therefore, the demand cannot be satisfied.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an SSD garbage collection method, an SSD garbage collection device, computer equipment and a storage medium.

In order to achieve the purpose, the invention adopts the following technical scheme:

the SSD garbage recycling method comprises the following steps:

selecting a sacrifice block, and reading data to be moved in the sacrifice block;

judging whether the data to be moved is cold data or hot data;

if the data is cold data, sorting the blocks according to the size of the erasing times, forming a moving maximum group with all the blocks of which the difference value of the erasing times of the current maximum erasing times is smaller than K, selecting the block with the longest operation time in the moving maximum group as a target block, erasing the target block, and moving the cold data to be moved to the erased target block;

if the data is hot data, sorting the blocks according to the size of the erasing times, forming a moving minimum group with all the blocks of which the difference value with the erasing times of the current minimum erasing times is smaller than M, selecting the block with the shortest operation time in the moving minimum group as a target block, erasing the target block, and moving the hot data to be moved to the erased target block.

The further technical scheme is as follows: before the step of selecting the victim block and reading the data to be moved in the victim block, the method further comprises the following steps: and starting the SSD garbage collection operation.

The further technical scheme is as follows: in the step of selecting the sacrifice block and reading the data to be moved in the sacrifice block, the principle of selecting the sacrifice block is to select the sacrifice block by comprehensively sorting according to the number of effective data in the block, the data writing time and the block erasing times.

The further technical scheme is as follows: the value of K is 0-500, and the value of M is 0-300.

SSD garbage collection device includes: a reading unit, a judging unit, a first sequencing moving unit and a second sequencing moving unit are selected;

the selective reading unit is used for selecting the sacrifice block and reading the data to be moved in the sacrifice block;

the judging unit is used for judging whether the data to be moved is cold data or hot data;

the first sequential moving unit is used for sorting the blocks according to the size of the erasing times, forming a moving maximum group with all the blocks of which the difference value of the erasing times with the current maximum erasing times is smaller than K, selecting the block with the longest operation time in the moving maximum group as a target block, erasing the target block, and moving the cold data to be moved to the erased target block;

and the second sorting and moving unit is used for sorting the blocks according to the erasing times, forming a moving minimum group with all the blocks of which the difference value with the current minimum erasing times is smaller than M, selecting the block with the shortest operation time in the moving minimum group as a target block, erasing the target block, and moving the hot data to be moved to the erased target block.

The further technical scheme is as follows: further comprising: and the starting unit is used for starting the SSD garbage recycling operation.

The further technical scheme is as follows: in the selective reading unit, the principle of selecting the sacrifice blocks is to select the sacrifice blocks by comprehensively sorting according to the number of effective data in the blocks, the data writing time and the block erasing times.

A computer device comprising a memory having stored thereon a computer program and a processor that when executed implements an SSD garbage collection method as described above.

A storage medium storing a computer program comprising program instructions which, when executed by a processor, may implement an SSD garbage collection method as described above.

Compared with the prior art, the invention has the beneficial effects that: the data to be moved is judged to be cold data or hot data, the data to be moved is used as a reference basis for target block selection aiming at block operation time factors, a block with small erasing times and short operation time is distributed to the hot data to be used as a target block according to the cold and hot data type of the data to be moved and combined with the erasing times and the block operation time factors of the target block, and a block with large erasing times and long operation time is distributed to the cold data to be used as the target block, so that the overall service life and performance of the SSD can be effectively prolonged, and the requirement can be better met.

The invention is further described below with reference to the accompanying drawings and specific embodiments.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of an application of SSD garbage collection;

fig. 2 is a schematic flowchart of an SSD garbage collection method according to an embodiment of the present invention;

FIG. 3 is a block operation time statistic diagram according to an embodiment of the present invention;

fig. 4 is a schematic block diagram of an SSD garbage collection apparatus provided by an embodiment of the present invention;

FIG. 5 is a schematic block diagram of a computer device provided by an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

Referring to the specific embodiments shown in fig. 1 to 5, referring to the SSD garbage collection diagram shown in fig. 1, due to the basic characteristics of NAND Flash, a NAND Flash block needs to be erased before writing, and cannot be overwritten, so that after a period of read-write operation, valid data and invalid data exist in data on the NAND Flash block, in order to ensure normal writing of data and performance of the SSD, a Garbage Collection (GC) operation needs to be started, valid data in a sacrificial block is moved to a target block, and then the sacrificial block is erased to become an idle block. In the existing target block selection method for Garbage Collection (GC), the erasing times (EC) are used as a unique reference factor, and the specific process is as follows: 1. selecting a sacrifice speed; 2. sorting according to the erasing times, and preferentially selecting the block with the small erasing times as a target block; 3. and moving the data to be moved in the sacrifice cache to the target block. The existing operation can cause the waste of resources and influence the whole service life of the SSD.

Referring to fig. 2 to 3, the present invention discloses a method for recycling SSD garbage, comprising the following steps:

s1, selecting a sacrifice block, and reading the data to be moved in the sacrifice block;

s2, judging the data to be moved as cold data or hot data;

s3, if the data are cold data, sorting the blocks according to the erasing times, forming a moving maximum group with all the blocks of which the difference value of the erasing times of the current maximum erasing times is smaller than K, selecting the block with the longest operation time in the moving maximum group as a target block, erasing the target block, and moving the cold data to be moved to the erased target block;

and S4, if the data are hot data, sorting the blocks according to the erasing times, forming a moving minimum group with all the blocks of which the difference value of the erasing times with the current minimum erasing time block is less than M, selecting the block with the shortest operation time in the moving minimum group as a target block, erasing the target block, and moving the hot data to be moved to the erased target block.

Referring to fig. 3, for statistics of block operation time, the maximum operation time (i.e., scrub) Tmax of each block is recorded through the RDT process in the mass production stage, and the operation time of the ith block is recorded as Tmax (i) ═ temax (i) + tpmax (i) + trmax (i); wherein i is an arbitrary number.

Before the step S1, the method further includes: and starting SSD garbage collection operation to start SSD garbage collection.

In step S1, the principle of selecting the victim block is to select the victim block by comprehensively sorting according to the number of valid data in the block, the data writing time, the block erasing times, and other factors.

In the embodiment, the value of K is 0 to 500, and the value of M is 0 to 300; in other embodiments, the value of K and the value of M may be set according to actual requirements.

According to the invention, the data to be moved is judged to be cold data or hot data, the data to be moved is used as a reference basis for target block selection aiming at the block operation time factor, a block with small erasing times and short operation time is allocated to the hot data as a target block, and a block with large erasing times and long operation time is allocated to the cold data as a target block according to the cold and hot data type of the data to be moved by combining the erasing times and the block operation time factor of the target block, so that the whole service life and performance of the SSD can be effectively improved, and the requirement can be better met.

Referring to fig. 4, the present invention also discloses an SSD garbage collection device, including: a selection reading unit 10, a judgment unit 20, a first sorting and moving unit 30, and a second sorting and moving unit 40;

the selective reading unit 10 is configured to select a sacrificial block and read data to be moved in the sacrificial block;

the judging unit 20 is configured to judge that the data to be moved is cold data or hot data;

the first sequential moving unit 30 is configured to sequence the blocks according to the size of the erase times, form a maximum moving group with all the blocks whose difference between the erase times of the current maximum erase-time block and the erase times of the current maximum erase-time block is smaller than K, select the block with the longest operation time in the maximum moving group as a target block, erase the target block, and move the cold data to be moved to the erased target block;

the second sorting and moving unit 40 is configured to sort the blocks according to the size of the erasing times, form a moving minimum group with all the blocks of which the difference value between the erasing times and the current minimum erasing time block is smaller than M, select the block with the shortest operation time in the moving minimum group as a target block, erase the target block, and move the hot data to be moved to the erased target block.

Wherein, the device still includes: and the starting unit 50 is used for starting the SSD garbage collection operation.

In the selective reading unit 10, the principle of selecting the victim block is to select the victim block by comprehensively sorting according to a number of valid data in the block, data writing time, block erasing times, and other factors.

Wherein the value of K is 0-500, and the value of M is 0-300.

It should be noted that, as can be clearly understood by those skilled in the art, the specific implementation processes of the SSD garbage collection device and each unit may refer to the corresponding descriptions in the foregoing method embodiments, and for convenience and brevity of description, no further description is provided herein.

The SSD garbage collection apparatus described above may be implemented in the form of a computer program that can be run on a computer device as shown in fig. 5.

Referring to fig. 5, fig. 5 is a schematic block diagram of a computer device according to an embodiment of the present application; the computer device 500 may be a terminal or a server, where the terminal may be an electronic device with a communication function, such as a smart phone, a tablet computer, a notebook computer, a desktop computer, a personal digital assistant, and a wearable device. The server may be an independent server or a server cluster composed of a plurality of servers.

Referring to fig. 5, the computer device 500 includes a processor 502, memory, and a network interface 505 connected by a system bus 501, where the memory may include a non-volatile storage medium 503 and an internal memory 504.

The non-volatile storage medium 503 may store an operating system 5031 and a computer program 5032. The computer programs 5032 include program instructions that, when executed, cause the processor 502 to perform an SSD garbage collection method.

The processor 502 is used to provide computing and control capabilities to support the operation of the overall computer device 500.

The memory 504 provides an environment for the operation of the computer program 5032 in the non-volatile storage medium 503, and when the computer program 5032 is executed by the processor 502, the processor 502 may be enabled to execute an SSD garbage collection method.

The network interface 505 is used for network communication with other devices. Those skilled in the art will appreciate that the configuration shown in fig. 5 is a block diagram of only a portion of the configuration associated with the present application and does not constitute a limitation of the computer device 500 to which the present application may be applied, and that a particular computer device 500 may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.

It should be understood that, in the embodiment of the present Application, the Processor 502 may be a Central Processing Unit (CPU), and the Processor 502 may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, and the like. Wherein a general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It will be understood by those skilled in the art that all or part of the flow of the method implementing the above embodiments may be implemented by a computer program instructing associated hardware. The computer program includes program instructions, and the computer program may be stored in a storage medium, which is a computer-readable storage medium. The program instructions are executed by at least one processor in the computer system to implement the flow steps of the embodiments of the method described above.

Accordingly, the present invention also provides a storage medium. The storage medium may be a computer-readable storage medium. The storage medium stores a computer program, wherein the computer program comprises program instructions that, when executed by a processor, implement the SSD garbage collection method described above.

The storage medium may be a usb disk, a removable hard disk, a Read-Only Memory (ROM), a magnetic disk, or an optical disk, which can store various computer readable storage media.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative. For example, the division of each unit is only one logic function division, and there may be another division manner in actual implementation. For example, various elements or components may be combined or may be integrated into another system, or some features may be omitted, or not implemented.

The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs. The units in the device of the embodiment of the invention can be merged, divided and deleted according to actual needs. In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a storage medium. Based on such understanding, the technical solution of the present invention essentially or partially contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a terminal, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention.

The technical contents of the present invention are further illustrated by the examples only for the convenience of the reader, but the embodiments of the present invention are not limited thereto, and any technical extension or re-creation based on the present invention is protected by the present invention. The protection scope of the invention is subject to the claims.

Claims

The SSD garbage recycling method is characterized by comprising the following steps:

selecting a sacrifice block, and reading data to be moved in the sacrifice block;

judging whether the data to be moved is cold data or hot data;

if the data is cold data, sorting the blocks according to the size of the erasing times, forming a moving maximum group with all the blocks of which the difference value of the erasing times of the current maximum erasing times is smaller than K, selecting the block with the longest operation time in the moving maximum group as a target block, erasing the target block, and moving the cold data to be moved to the erased target block;

if the data is hot data, sorting the blocks according to the size of the erasing times, forming a moving minimum group with all the blocks of which the difference value with the erasing times of the current minimum erasing times is smaller than M, selecting the block with the shortest operation time in the moving minimum group as a target block, erasing the target block, and moving the hot data to be moved to the erased target block.
2. The SSD garbage collection method according to claim 1, wherein before the step of selecting the victim block and reading the data to be moved in the victim block, the method further comprises: and starting the SSD garbage collection operation.
3. The SSD garbage collection method of claim 1, wherein in the step of selecting victim blocks, reading data to be moved in the victim blocks, the principle of selecting the victim blocks is to select the victim blocks by comprehensively sorting according to the number of valid data in the blocks, data write-in time, and block erase times.
4. The SSD garbage collection method of claim 1, wherein K has a value of 0-500 and M has a value of 0-300.
An SSD garbage collection apparatus, comprising: a reading unit, a judging unit, a first sequencing moving unit and a second sequencing moving unit are selected;

the selective reading unit is used for selecting the sacrifice block and reading the data to be moved in the sacrifice block;

the judging unit is used for judging whether the data to be moved is cold data or hot data;

the first sequential moving unit is used for sorting the blocks according to the size of the erasing times, forming a moving maximum group with all the blocks of which the difference value of the erasing times with the current maximum erasing times is smaller than K, selecting the block with the longest operation time in the moving maximum group as a target block, erasing the target block, and moving the cold data to be moved to the erased target block;

and the second sorting and moving unit is used for sorting the blocks according to the erasing times, forming a moving minimum group with all the blocks of which the difference value with the current minimum erasing times is smaller than M, selecting the block with the shortest operation time in the moving minimum group as a target block, erasing the target block, and moving the hot data to be moved to the erased target block.
6. The SSD garbage collection device of claim 5, further comprising: and the starting unit is used for starting the SSD garbage recycling operation.
7. The SSD garbage collection device of claim 5, wherein in the select read unit, the principle of selecting victim blocks is to select victim blocks by comprehensively sorting according to the number of valid data in a block, data write time, and block erase times.
8. The SSD garbage collection device of claim 5, wherein K has a value of 0-500 and M has a value of 0-300.
9. A computer device comprising a memory having stored thereon a computer program and a processor that, when executed, implements the SSD garbage collection method of any of claims 1-4.
10. A storage medium, characterized in that the storage medium stores a computer program comprising program instructions which, when executed by a processor, implement the SSD garbage collection method of any of claims 1-4.