Managing memory of a computer

Patent metadata

Field	Value
Publication number	US-9003146-B2
Application number	US-201213564958-A
Country	US
Kind code	B2
Filing date	Aug 2, 2012
Priority date	Aug 3, 2011
Publication date	Apr 7, 2015
Grant date	Apr 7, 2015

Abstract

A method for managing data in a memory of a computer. The method includes the steps of: prohibiting a specified memory area in a memory from being accessed temporarily or intermittently; and attaching, to first data, a first mark indicating that the first data has been read when a page fault has occurred as a result of an access by any process to read on the first data; where the first data is present in a specified memory area prohibited from being accessed; and where at least one of the steps is carried out using a computer device.

First claim

What is claimed is:

1. A method for managing data in a memory of a computer, the method comprising:
setting a state of a specified memory area in the memory to a first state, the first state prohibiting the specified memory area from being read or write accessed;
detecting a page fault at an address of a first data present in the specified memory area, the page fault being a result of an access on first data; and
in response to the access on first data being determined as a read access
attaching, to the first data, a first mark indicating that the first data has been read, and
altering the state to a second state, the second state enabling only read access to the specified memory area.

2. The method according to claim 1 , further comprising:
altering the state to a second state after attaching the first mark to the first data, the second state preventing write access to the specified memory area.

3. The method according to claim 1 , further comprising:
in response to the access being determined as a write access
attaching, to the first data, a second mark indicating that the second data has been written, and
altering the state to a third state, the third state enabling read and write access to the specified memory.

4. The method according to claim 3 , further comprising:
moving the first data to an individual memory partition based on whether the first or second mark was attached.

5. The method according to claim 4 , wherein the moving of the first data is performed in response to a garbage collection or a restart of a process that executes the access on first data that caused the page fault.

6. A method for managing data in a memory of a computer, the method comprising:
setting a state of a specified memory area in the memory to a first state, the first state prohibiting the specified memory area from being write accessed;
detecting a page fault at an address of a first data present in the specified memory area, the page fault being a result of an access on first data; and
in response to the access being determined as a write access
attaching, to data, a mark indicating that the data has been written, and
altering the state to a second state, the second state enabling read and write access to the specified memory area.

7. The method according to claim 6 , further comprising:
moving the data having the mark into a separate memory partition.

8. A computer program product for managing data in a memory of a computer, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by the computer to cause the computer to:
setting a state of a specified memory area in the memory to a first state, the first state prohibiting the specified memory area from being read or write accessed;
detecting a page fault at an address of a first data present in the specified memory area, the page fault being a result of an access on first data; and
in response to the access on first data being determined as a read access
attaching, to the first data, a first mark indicating that the first data has been read, and
altering the state to a second state, the second state enabling only read access to the specified memory area.

9. The computer readable storage medium according to claim 8 , wherein the program instructions are further executable by the computer to cause:
altering the state to a second state after attaching the first mark to the first data, the second state preventing write access to the specified memory area.

10. The computer readable storage medium according to claim 8 , wherein the program instructions are further executable by the computer to cause:
in response to the access being determined as a write access:
attaching, to the first data, a second mark indicating that the second data has been written, and
altering the state to a third state, the third state enabling read and write access to the specified memory area.

11. The computer readable storage medium according to claim 10 , wherein the program instructions are further executable by the computer to cause:
moving the first data to an individual memory partition based on whether the first or second mark was attached.

12. The computer readable storage medium according to claim 11 , wherein the moving of the first data is performed in response to a garbage collection or a restart of a process that executes the access on first data that caused the page fault.

13. A system for managing data, comprising:
a computer having at least one processor and a memory, the computer configured to:
set a state of a specified memory area in the memory to a first state, wherein the first state prohibits the specified memory area from being write accessed;
detect a page fault at an address of a first data present in the specified memory area, wherein the page fault is a result of an access on first data; and
in response to a determination that the access is a read access:
attach, to the first data, a first mark that indicates that the first data has been read, and
alter the state to a second state, wherein the second state enables only read access to the specified memory area.

14. The system according to claim 13 , wherein the computer is further configured to:
alter the state to a second state after the first mark is attached to the first data, wherein the second state prevents write access to the specified memory area.

15. The system according to claim 13 , wherein the computer is further configured to:
in response to a determination that the access is a write access:
attach, to the first data, a second mark that indicates that the second data has been written, and
alter the state to a third state, wherein the third state enables read and write access to the specified memory area.

16. The system according to claim 15 , wherein the computer is further configured to:
move the first data to an individual memory partition based on whether the first or second mark was attached.

17. The system according to claim 16 , wherein the movement of the first data is performed in response to a garbage collection or a restart of a process that executes the access on first data that caused the page fault.

Assignees

• Kawachiya Kiyokuni
• Ogata Kazunori
• IBM

Inventors

• Kawachiya Kiyokuni
• Ogata Kazunori

Classifications

• G06F9/46

  Multiprogramming arrangements · CPC title

• G06F12/0253 Primary

  Garbage collection, i.e. reclamation of unreferenced memory · CPC title

• G06F12/14

  Protection against unauthorised use of memory {or access to memory} · CPC title

• G06F12/02 Primary

  Addressing or allocation; Relocation (program address sequencing G06F9/00; arrangements for selecting an address in a digital store G11C8/00) · CPC title

• G06F12/1433

  for a module or a part of a module · CPC title