Delayed trim of managed NAND flash memory in computing devices

• US 10,296,259 B2
• Filed: 12/15/2015
• Issued: 05/21/2019
• Est. Priority Date: 12/22/2014
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Kent, Klair, Redondo, Ramon C.
• Primary Examiner(s): Lo, Ann J
• Assistant Examiner(s): Wei, Jane
• Application Number:
  US14/969,198
• Publication Number:
  US 20160179378A1
• Time in Patent Office: 1,253 Days
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652
• CPC Class Codes: G06F 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A method of managing NAND flash memory in an electronic device whereby system performance of the electronic device is minimally impacted is disclosed. The method comprises collecting files that are marked for deletion or truncation; monitoring an activity level of the electronic device; monitoring a total size of the list of files that are marked for deletion or truncation; determining if the electronic device is idle; and trimming the flash memory of the electronic device if predetermined criteria are met.

Claims

1. A method of managing NAND flash memory in an electronic device, comprising:

collecting files that are marked for deletion or truncation;

monitoring an activity level of the electronic device;

creating a system folder in the NAND flash memory to contain files marked for deletion or truncation;

moving files marked for deletion or truncation to the system folder;

monitoring a size of the system folder in the NAND flash memory;

determining if the electronic device is idle;

in an instance in which the activity level of the electronic device is determined to be idle, trimming the system folder; and

in an instance in which the size of the system folder in the NAND flash memory exceeds a predetermined size, trimming the system folder, wherein trimming the system folder comprises deleting the files in the system folder.

2. The method of claim 1, comprising loading a file system filter driver at boot time of the electronic device.

3. The method of claim 1, comprising setting a correct filter mode of the file system driver.

4. The method of claim 1, comprising assigning a thread priority to the file system filter driver.

5. The method of claim 1, comprising creating hooks to a file system of the electronic device from the file system device driver.

6. The method of claim 1, comprising extending file system I/O functions to the file system device driver.

7. The method of claim 1, comprising spawning a process to monitor idle time of the electronic device.

8. The method of claim 1, comprising spawning a process to monitor the system folder.

9. The method of claim 1, wherein trimming the flash memory of the electronic device occurs at the next reboot of the electronic device.

10. The method of claim 1, wherein trimming the flash memory of the electronic device occurs when the electronic device is determined to be idle.

11. An electronic device, comprising:

a NAND flash memory with a file system;

an operating system having file system I/O functions; and

a file system filter driver operative to;

execute file system I/O functions of the operating system,

monitor an activity level of the electronic device,

create a system folder on the NAND flash memory to contain files that are marked for deletion or truncation,

move files that are marked for deletion or truncation to the system folder,

determine if the electronic device is idle,

monitor the size of the system folder,

trim the system folder at an instance when the activity level of the electronic device is determined to be idle; and

trim the system folder at an instance when the size of the system folder on the NAND flash memory exceeds a predetermined size, wherein trimming the system folder comprises deleting the files in the system folder.

12. The electronic device of claim 11, wherein the electronic device is configured to load the file system filter driver at boot time of the electronic device.

13. The electronic device of claim 11, wherein the file system filter driver is operative to spawn a process to monitor idle time of the electronic device.

14. The electronic device of claim 11, wherein the file system filter driver is operative to spawn a process to monitor the system folder.

15. The electronic device of claim 11, wherein the file system filter driver is operative to trim the flash memory of the electronic device at the next reboot of the electronic device.

16. The electronic device of claim 11, wherein the file system filter driver is operative to trim the flash memory of the electronic device when the electronic device is determined to be idle.