MEMORY MANAGEMENT METHOD

• US 20150363311A1
• Filed: 05/27/2015
• Published: 12/17/2015
• Est. Priority Date: 06/17/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Munetoh, Seiji, Ohba, Nobuyuki
• Granted Patent: US 9,552,291 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0638 Combination of memories, e.g. ROM and RAM such as to permit replacement or supplementing of words in one module by words in another module address formation of the next microinstruction G06F9/26; masking faults in memories by using spares or by reconfiguring G11C29/70
• CPC Class Codes: G06F 2212/205 Hybrid memory, e.g. using both volatile and non-volatile memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 9/4406 Loading of operating system
• CPC Class Codes: G11C 11/4096 Input/output [I/O] data management or control circuits, e.g. reading or writing circuits, I/O drivers or bit-line switches
• CPC Class Codes: G11C 14/0009 in which the volatile element is a DRAM cell

Abstract

A method for managing main memory including DRAM and NVRAM in a computer depending on the operation state of the computer is provided. The method includes: (a) upon start of the computer, loading a program and the like into the DRAM, and loading predetermined read-only data and the like into the NVRAM; (b) in a state transition from a normal operation to a suspend state, moving data in the DRAM to the NVRAM; (c) in a state transition from the suspend state to the normal operation, reading data from the NVRAM for program execution; (d) in the case where a data write to the NVRAM occurs, stopping the data write, and moving data in a data area of the NVRAM subjected to the data write, to the DRAM; and (e) performing the data write to the DRAM to which the data has been moved.

Claims

1. A method for managing main memory including DRAM and NVRAM in a computer depending on a transition of an operation state of the computer, the method comprising:

a step (a) of, upon start of the computer, loading at least one of a program and data into the DRAM, and loading at least one of a predetermined program and read-only data into the NVRAM;

a step (b) of, in a state transition from a normal operation to a suspend state of the computer, moving data in the DRAM to the NVRAM on a page basis;

a step (c) of, in a state transition from the suspend state to the normal operation of the computer, reading data from the NVRAM on a page basis for program execution by the computer;

a step (d) of, in the case where a data write to the NVRAM on a page basis occurs in the step (c) of reading data from the NVRAM on a page basis, stopping the data write, and moving data in a data area of the NVRAM subjected to the data write, to the DRAM on a page basis; and

a step (e) of performing the data write on a page basis to the DRAM to which the data has been moved.

2. The method according to claim 1, further comprising:

a step of detecting a use state of the DRAM; and

a step of moving a page in the DRAM that has not been read for a time T1 or has not been written for a time T2, to the NVRAM.

3. The method according to claim 2, wherein the step of detecting a use state of the DRAM is performed:

(i) at predetermined time intervals;

(ii) in the case where an operating ratio of a processor in the computer is less than or equal to a predetermined value;

or (iii) in the case where no input to the computer has been made for a predetermined time.

4. The method according to claim 1, wherein the step (b) of moving data in the DRAM to the NVRAM on a page basis includes a step of moving data in the DRAM to an external storage device.

5. The method according to claim 1, wherein the step (b) of moving data in the DRAM to the NVRAM on a page basis includes a step of updating a corresponding page table each time data is moved.

6. The method according to claim 1, wherein the step (e) of performing the data write on a page basis to the DRAM to which the data has been moved includes a step of updating a corresponding page table each time data is written.

7. The method according to claim 1, wherein the operation state of the computer is an operation state conforming to the Advanced Configuration and Power Interface (ACPI) standard.

8. The method according to claim 4, wherein the step (b) of moving data in the DRAM to the NVRAM on a page basis includes a step of updating a corresponding page table each time data is moved.

9. A computer program product for managing main memory including DRAM and NVRAM in a computer depending on a transition of an operation state of the computer, the computer program product comprising at least one computer readable non-transitory storage medium having computer readable program instructions thereon for execution by a processor, the computer readable program instructions comprising program instructions for:

upon start of the computer, loading at least one of a program and data into the DRAM, and loading at least one of a predetermined program and read-only data into the NVRAM;

in a state transition from a normal operation to a suspend state of the computer, moving data in the DRAM to the NVRAM on a page basis;

in a state transition from the suspend state to the normal operation of the computer, reading data from the NVRAM on a page basis for program execution by the computer;

in the case where a data write to the NVRAM on a page basis occurs in the reading data from the NVRAM on a page basis, stopping the data write, and moving data in a data area of the NVRAM subjected to the data write, to the DRAM on a page basis; and

performing the data write on a page basis to the DRAM to which the data has been moved.

10. The computer program product according to claim 9, further comprising program instructions for:

detecting a use state of the DRAM; and

moving a page in the DRAM that has not been read for a time T1 or has not been written for a time T2, to the NVRAM.

11. The computer program product according to claim 10, wherein the detecting a use state of the DRAM is performed:

(i) at predetermined time intervals;

(ii) in the case where an operating ratio of a processor in the computer is less than or equal to a predetermined value;

or (iii) in the case where no input to the computer has been made for a predetermined time.

12. The computer program product according to claim 9, wherein the moving data in the DRAM to the NVRAM on a page basis includes a step of moving data in the DRAM to an external storage device.

13. A computer system for managing main memory including DRAM and NVRAM in a computer depending on a transition of an operation state of the computer, the computer system comprising:

at least one processor;

at least one computer readable memory;

at least one computer readable tangible, non-transitory storage medium; and

program instructions stored on the at least one computer readable tangible, non-transitory storage medium for execution by the at least one processor via the at least one computer readable memory,

wherein the at least one computer readable memory includes the main memory including DRAM and NVRAM, and

wherein the program instructions comprise program instructions for;

upon start of the computer, loading at least one of a program and data into the DRAM, and loading at least one of a predetermined program and read-only data into the NVRAM;

in a state transition from a normal operation to a suspend state of the computer, moving data in the DRAM to the NVRAM on a page basis;

in a state transition from the suspend state to the normal operation of the computer, reading data from the NVRAM on a page basis for program execution by the computer;

in the case where a data write to the NVRAM on a page basis occurs in the reading data from the NVRAM on a page basis, stopping the data write, and moving data in a data area of the NVRAM subjected to the data write, to the DRAM on a page basis; and

performing the data write on a page basis to the DRAM to which the data has been moved.

14. The computer system according to claim 13, further comprising program instructions for:

detecting a use state of the DRAM; and

moving a page in the DRAM that has not been read for a time T1 or has not been written for a time T2, to the NVRAM.

15. The computer system according to claim 14, wherein the detecting a use state of the DRAM is performed:

(i) at predetermined time intervals;

(ii) in the case where an operating ratio of the at least one processor in the computer is less than or equal to a predetermined value;

or (iii) in the case where no input to the computer has been made for a predetermined time.

16. The computer system according to claim 13, further comprising an external storage device, wherein the moving data in the DRAM to the NVRAM on a page basis includes a step of moving data in the DRAM to the external storage device.

17. The computer system according to claim 13, wherein the moving data in the DRAM to the NVRAM on a page basis includes a step of updating a corresponding page table each time data is moved.

18. The computer system according to claim 13, wherein the performing the data write on a page basis to the DRAM to which the data has been moved includes a step of updating a corresponding page table each time data is written.

19. The computer system according to claim 13, wherein the operation state of the computer is an operation state conforming to the Advanced Configuration and Power Interface (ACPI) standard.

20. The computer system according to claim 16, wherein the moving data in the DRAM to the NVRAM on a page basis includes a step of updating a corresponding page table each time data is moved.