THERMALLY SENSITIVE WEAR LEVELING FOR A FLASH MEMORY DEVICE THAT INCLUDES A PLURALITY OF FLASH MEMORY MODULES
Thermally sensitive wear leveling for a flash memory device that includes a plurality of flash memory modules, the flash memory device included in a computing system that includes a plurality of additional computing components, including: identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components; identifying wear leveling information for each flash memory module; receiving a request to write data to the flash memory device; selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device; and writing the data to the target flash memory module.
1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for thermally sensitive wear leveling for a flash memory device that includes a plurality of flash memory modules.
2. Description of Related Art
Modern computing devices can include storage devices that utilized flash-based memory. The performance of such flash-based memory, however, is only guaranteed to be reliable when the flash-based memory is at a temperature that is below and predetermined threshold. In addition, the performance of such flash-based memory is also only guaranteed to be reliable when the flash-based memory has been written to less than a predetermined number of times.
SUMMARY OF THE INVENTIONMethods, apparatuses, and products for thermally sensitive wear leveling for a flash memory device that includes a plurality of flash memory modules, the flash memory device included in a computing system that includes a plurality of additional computing components, including: identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components; identifying wear leveling information for each flash memory module; receiving a request to write data to the flash memory device; selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device; and writing the data to the target flash memory module.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of example embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of example embodiments of the invention.
Example methods, apparatuses, and products for thermally sensitive wear leveling for a flash memory device in accordance with the present invention are described with reference to the accompanying drawings, beginning with
The computer (152) of
The flash memory device (224) depicted in
The flash memory device (224) depicted in
Readers will appreciate that because certain flash memory modules (226, 228, 230) may be closer to heat generating sources such a computer processor, certain flash memory modules (226, 228, 230) may be exposed to more externally generated heat than other flash memory modules (226, 228, 230). Readers will similarly appreciate that because certain flash memory modules (226, 228, 230) may be closer to heat removing sources such a computer fan, certain flash memory modules (226, 228, 230) may have heat removed more efficiently than other flash memory modules (226, 228, 230). As such, each flash memory module (226, 228, 230) may be thermally impacted by its physical surroundings in a different manner.
The computer depicted in
The computer (152) of
The computer (152) of
The example computer (152) of
The example computer (152) of
For further explanation,
The flash memory device (224) depicted in
The flash memory device (224) depicted in
Readers will appreciate that because certain flash memory modules (226, 228, 230) may be closer to heat generating sources such a computer processor, certain flash memory modules (226, 228, 230) may be exposed to more externally generated heat than other flash memory modules (226, 228, 230). Readers will similarly appreciate that because certain flash memory modules (226, 228, 230) may be closer to heat removing sources such a computer fan, certain flash memory modules (226, 228, 230) may have heat removed more efficiently than other flash memory modules (226, 228, 230). As such, each flash memory module (226, 228, 230) may be thermally impacted by its physical surroundings in a different manner.
The example method depicted in
In the example depicted in
In the example method depicted in
The example method depicted in
Wear leveling of the flash memory modules (226, 228, 230) of the flash memory device (224) is carried out by equally, at least within a predetermined tolerance, distributing write accesses to flash memory modules (226, 228, 230) of the flash memory device (224). Wear leveling is important in view of the fact that memory cells and memory blocks becomes worn out and unreliable the more frequently that data is written to the memory cells and the memory blocks. As such, if the memory controller (206) operated by writing data to one flash memory module (226) in the flash memory device (224) much more frequently than another flash memory module (230) of the flash memory device (224), the flash memory module (226) that is written to more frequently would become worn out and unreliable while other flash memory modules (228, 230) in the flash memory device (224) that are written to less frequently would still function properly. In order to avoid prematurely wearing out certain flash memory modules (226, 228, 230) of the flash memory device (224) while simultaneously underutilizing properly functioning flash memory modules (226, 228, 230) of the flash memory device (224), a predictive failure algorithm may be utilized to intelligently distribute write accesses in a relatively uniform manner across all flash memory modules (226, 228, 230) of the flash memory device (224), such that each flash memory module (226, 228, 230) of the flash memory device (224) wears out in a relatively uniform manner. The wear leveling information (214) may therefore be utilized to steer new write access requests to those flash memory modules (226, 228, 230) that have been written to less frequently.
The example method depicted in
The example method depicted in
As described above, a predictive failure algorithm may carry out wear leveling of the flash memory device (224) by taking into account the number of times that a particular flash memory module (226, 228, 230) has been written to when determining which location in the flash memory device (224) that data should be written to in response to the memory controller (206) receiving a request (204) to write data to the flash memory device (224). The predictive failure algorithm may also take into account the extent to which a particular flash memory module (226, 228, 230) is thermally impacted by additional computing components (232) in the computing system (202) when determining which location in the flash memory device (224) data should be written to in response to the memory controller (206) receiving a request (204) to write data to the flash memory device (224).
Consider an example in which the thermal sensitivity coefficient (210) for each flash memory module (226, 228, 230) is determined based on the proximity of each flash memory module (226, 228, 230) to a heat generating computer processor. In such an example, the predictive failure algorithm may be structured such that during periods of time in which the computer processor is executing a large number of instructions (and thereby generating a large amount of heat), flash memory modules (226, 228, 230) whose thermal sensitivity coefficients (210) indicate that the flash memory modules (226, 228, 230) are furthest away from the computer processor are targeted for servicing write access requests. The predictive failure algorithm may be similarly structured such that during periods of time in which the computer processor is executing a small number of instructions (and thereby not generating a large amount of heat), flash memory modules (226, 228, 230) whose thermal sensitivity coefficients (210) indicate that the flash memory modules (226, 228, 230) are closest to the computer processor are targeted for servicing write access requests. In such a way, flash memory modules (226, 228, 230) that are more sensitive to heat produced by the computer processor are utilized when the computer processor is not generating much heat while flash memory modules (226, 228, 230) that are less sensitive to heat produced by the computer processor are utilized when the computer processor is generating larger amounts of heat.
For further explanation, consider an additional example in which the thermal sensitivity coefficients (210) for each flash memory module (226, 228, 230) are identified based on the proximity of each flash memory module (226, 228, 230) to a computer fan. In such an example, the predictive failure algorithm may be structured such that during periods of time in which a large number of write access requests are being serviced by the flash memory device (224) (thereby causing the flash memory device to generate a relatively large amount of heat), flash memory modules (226, 228, 230) whose thermal sensitivity coefficients (210) indicate that the flash memory modules (226, 228, 230) are closest to computer fans are targeted for servicing write access requests. The predictive failure algorithm may be similarly structured such that during periods of time in which a smaller number of write access requests are being serviced by the flash memory device (224) (thereby causing the flash memory device to generate a relatively small amount of heat), the flash memory modules (226, 228, 230) whose thermal sensitivity coefficients (210) indicate that the flash memory modules (226, 228, 230) are furthest from the computer fans may be targeted for servicing write access requests. In such a way, flash memory modules (226, 228, 230) that are more efficiently cooled by the computer fan are utilized when the flash memory modules (226, 228, 230) are generating larger amounts of heat while flash memory modules (226, 228, 230) that are less efficiently cooled by the computer fan are utilized when the flash memory modules (226, 228, 230) are generating smaller amounts of heat.
In the example method depicted in
Score=TW+(TC*WA),
where TW is equal to the total number of write accesses previously serviced by a particular flash memory module (226, 228, 230), TC is the thermal sensitivity coefficient (210) for a particular flash memory module (226, 228, 230), and WA is the number of write accesses directed to the flash memory device (224) during a predetermined period of time. In such an example, assume that the flash memory module (226, 228, 230) associated with the lowest score will be selected (218) to service the request (204) to write data to the flash memory device (224). Further assume that a low thermal sensitivity coefficient (210) means that a particular memory module (226, 228, 230) is less affected by heat generated by other computing components.
By utilizing the predictive failure algorithm included above, a flash memory module (226, 228, 230) that has previously serviced a relatively high number of write accesses will have one component (TW) of the predictive failure algorithm driving its score higher than a flash memory module (226, 228, 230) that has previously serviced a relatively low number of write accesses, thereby promoting wear leveling. In addition, during periods where the number of write accesses that are directed to the flash memory device (214) is relatively large, the score for a flash memory module (226, 228, 230) with a relatively high thermal sensitivity coefficient (210) is more heavily impacted than would occur during periods where the number of write accesses that are directed to the flash memory device (214) is relatively small, thereby making it less likely that a flash memory module (226, 228, 230) with a relatively high thermal sensitivity coefficient (210) would be selected for servicing a write access during periods of heavy activity where the flash memory device (210) is exposed to large amounts of heat.
Consider an example in which a first flash memory module (226) has previously serviced 11,000 write accesses and a second memory flash module (228) has previously serviced 10,000 write accesses. Assume in such an example that the first flash memory module (226) is not very sensitive to heat generated by other computing components and therefore has a thermal sensitivity coefficient (210) of 0.1, while the second flash memory module (228) is very sensitive to heat generated by other computing components and therefore has a thermal sensitivity coefficient (210) of 0.9. In a situation where the number of write accesses serviced by the flash memory device (224) is relatively low (e.g., 5 write accesses in the immediately preceding predetermined period of time), the second flash memory module (228) will be selected by virtue of its low number of previously serviced write accesses and in spite of its relatively high sensitivity to heat generated by the other computing components. In a situation where the number of write accesses serviced by the flash memory device (224) is relatively high (e.g., 10,000 write accesses in the immediately preceding predetermined period of time), however, the first flash memory module (226) will be selected by virtue of its relatively low sensitivity to heat generated by the other computing components and in spite of its higher number of previously serviced write accesses. Readers will appreciate that in the example described above, less thermally sensitive flash memory modules will be more heavily utilized during periods of high activity, while during periods of low activity wear leveling considerations will control. Readers will further appreciate that as a discrepancy in the number of write accesses increases between two flash memory modules, however, the less utilized flash memory module will eventually be more heavily utilized.
The example method depicted in
Readers will appreciate that the steps described above may be carried out by a system management module, a memory controller, or any combination thereof. In fact, the steps described above may be carried out by computer software executing on computer hardware in the computing system (202), by special purpose computer logic such as a circuit, controller, field-programmable gate array (‘FPGA’), or other form of computer logic included in the computing system (202), or by any combination thereof.
For further explanation,
In the example method depicted in
In the example method depicted in
Although steps 302 and 304 are described above as being alternative embodiments, readers will appreciate that identifying (208) a thermal sensitivity coefficient (210) for each flash memory module (226, 228, 230) can include both determining (302) a distance between each flash memory module (226, 228, 230) and a heat producing computing component and determining (304) a distance between each flash memory module (226, 228, 230) and a heat reducing computing component. Furthermore, multiple heat producing computing components and multiple heat reducing computing components may be taken into account when identifying (208) a thermal sensitivity coefficient (210) for each flash memory module (226, 228, 230).
In the example method depicted in
For further explanation,
In the example method depicted in
In the example method depicted in
In the example method depicted in
The present invention may be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention.
The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.
Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.
Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.
Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.
These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.
The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.
It will be understood from the foregoing description that modifications and changes may be made in various embodiments of the present invention without departing from its true spirit. The descriptions in this specification are for purposes of illustration only and are not to be construed in a limiting sense. The scope of the present invention is limited only by the language of the following claims.
Claims
1. A method of thermally sensitive wear leveling for a flash memory device that includes a plurality of flash memory modules, the flash memory device included in a computing system that includes a plurality of additional computing components, the method comprising:
- identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components;
- identifying wear leveling information for each flash memory module;
- receiving a request to write data to the flash memory device;
- selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device; and
- writing the data to the target flash memory module.
2. The method of claim 1 wherein identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components further comprises determining a distance between each flash memory module and a heat producing computing component.
3. The method of claim 1 wherein identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components further comprises determining a distance between each flash memory module and a heat reducing computing component.
4. The method of claim 1 wherein identifying wear leveling information for each flash memory module further comprises determining a number of times that data has been written to each flash memory module.
5. The method of claim 1 wherein selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device further comprises:
- identifying a least utilized flash memory module;
- identifying a utilization discrepancy threshold; and
- eliminating, from consideration as the target flash memory module, one or more flash memory modules that have been utilized more than the least utilized flash memory module by an amount equal to or in excess of the utilization discrepancy threshold.
6. The method of claim 1 wherein the flash memory device is a flash dual in-line memory module (DIMM).
7. An apparatus for thermally sensitive wear leveling for a flash memory device that includes a plurality of flash memory modules, the apparatus including the flash memory device and a plurality of additional computing components, the apparatus further comprising a computer processor, a computer memory operatively coupled to the computer processor, the computer memory having disposed within it computer program instructions that, when executed by the computer processor, cause the apparatus to carry out the steps of:
- identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components;
- identifying wear leveling information for each flash memory module;
- receiving a request to write data to the flash memory device;
- selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device; and
- writing the data to the target flash memory module.
8. The apparatus of claim 7 wherein identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components further comprises determining a distance between each flash memory module and a heat producing computing component.
9. The apparatus of claim 7 wherein identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components further comprises determining a distance between each flash memory module and a heat reducing computing component.
10. The apparatus of claim 7 wherein identifying wear leveling information for each flash memory module further comprises determining a number of times that data has been written to each flash memory module.
11. The apparatus of claim 7 wherein selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device further comprises:
- identifying a least utilized flash memory module;
- identifying a utilization discrepancy threshold; and
- eliminating, from consideration as the target flash memory module, one or more flash memory modules that have been utilized more than the least utilized flash memory module by an amount equal to or in excess of the utilization discrepancy threshold.
12. The apparatus of claim 7 wherein the flash memory device is a flash dual in-line memory module (‘DIMM’).
13. A computer program product for thermally sensitive wear leveling for a flash memory device that includes a plurality of flash memory modules, the flash memory device included in a computing system that includes a plurality of additional computing components, the computer program product disposed upon a computer readable medium, the computer program product comprising computer program instructions that, when executed, cause a computer to carry out the steps of:
- identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components;
- identifying wear leveling information for each flash memory module;
- receiving a request to write data to the flash memory device;
- selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device; and
- writing the data to the target flash memory module.
14. The computer program product of claim 13 wherein identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components further comprises determining a distance between each flash memory module and a heat producing computing component.
15. The computer program product of claim 13 wherein identifying a thermal sensitivity coefficient for each flash memory module in dependence upon a physical topology of the flash memory device and one or more of the additional computing components further comprises determining a distance between each flash memory module and a heat reducing computing component.
16. The computer program product of claim 13 wherein identifying wear leveling information for each flash memory module further comprises determining a number of times that data has been written to each flash memory module.
17. The computer program product of claim 13 wherein selecting, in dependence upon the thermal sensitivity coefficient for each flash memory module and the wear leveling information for each flash memory module, a target flash memory module for servicing the request to write data to the flash memory device further comprises:
- identifying a least utilized flash memory module;
- identifying a utilization discrepancy threshold; and
- eliminating, from consideration as the target flash memory module, one or more flash memory modules that have been utilized more than the least utilized flash memory module by an amount equal to or in excess of the utilization discrepancy threshold.
18. The computer program product of claim 13 wherein the flash memory device is a flash dual in-line memory module (‘DIMM’).
19. The computer program product of claim 13 wherein the computer readable medium comprises a signal medium.
20. The computer program product of claim 13 wherein the computer readable medium comprises a storage medium.
Type: Application
Filed: Aug 29, 2014
Publication Date: Mar 3, 2016
Inventors: KEITH M. CAMPBELL (CARY, NC), WILLIAM M. MEGARITY (RALEIGH, NC), LUKE D. REMIS (RALEIGH, NC), GREGORY D. SELLMAN (MORRISVILLE, NC), CHRISTOPHER L. WOOD (GREENVILLE, NC)
Application Number: 14/473,121
