Reuse of host hibernation storage space by memory controller

• US 8,694,814 B1
• Filed: 09/12/2010
• Issued: 04/08/2014
• Est. Priority Date: 01/10/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Salomon, Tavi, Shalvi, Ofir, Golov, Oren, Shachar, Michael
• Primary Examiner(s): Abbaszadeh, Jaweed A
• Application Number:
  US12/880,101
• Time in Patent Office: 1,304 Days
• Field of Search: 713/300, 713/321, 713/323, 713/324, 713/320, 711/100, 711/102, 711/103, 711/147
• US Class Current: 713/323
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: G06F 1/3234 Power saving characterised by the action undertaken
• CPC Class Codes: G06F 1/3268 Power saving in hard disk drive
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method for data storage includes, in a host system that operates alternately in a normal state and a hibernation state, reserving a hibernation storage space in a non-volatile storage device for storage of hibernation-related information in preparation for entering the hibernation state. While the host system is operating in the normal state, a storage task other than storage of the hibernation-related information is performed using at least a portion of the reserved hibernation storage space.

Claims

1. A method for data storage, comprising:

in a host system that operates alternately in a normal state and a hibernation state, reserving a hibernation storage space in a non-volatile storage device to store hibernation-related information in preparation for entering the hibernation state, wherein the non-volatile storage device includes multiple memory blocks allocated as a user data storage space, over-provisioning memory, and the hibernation storage space; and

while the host system is operating in the normal state;

allocating at least a portion of the hibernation storage space as over-provisioning memory, thereby allowing valid data to be copied from partially-programmed memory blocks in the user data storage space to the at least a portion of the hibernation storage space, and the valid data from the at least a portion of the hibernation storage space to be copied to the user data storage space subsequent to an erasure operation being performed one or more locations of the user data storage space.

2. The method according to claim 1, further comprising allocating at least another portion of the hibernation storage space as a cache, and caching user data accepted from the host system in the at least another portion of the hibernation storage space, and subsequently copying the cached user data to storage locations outside the hibernation storage space.

3. The method according to claim 2, wherein caching the user data comprises writing the user data to the hibernation storage space at a first storage throughput, and wherein copying the cached user data comprises storing the user data outside the hibernation storage space at a second storage throughput that is lower than the first storage throughput.

4. The method according to claim 1, wherein reserving the hibernation storage space comprises allocating a set of storage locations of the user data storage space by the host system to serve as the hibernation storage space, and wherein copying valid data to the at least a portion of the hibernation storage space comprises identifying at least part of the storage locations in the set, and using the identified storage locations.

5. The method according to claim 4, wherein identifying the storage locations in the set comprises receiving a notification from the host system indicative of the set of storage locations.

6. The method according to claim 4, wherein identifying the storage locations in the set comprises automatically identifying a file holding the hibernation-related information in a file system of the host system.

7. The method according to claim 4, further comprising, in preparation for entering the hibernation state, receiving the hibernation-related information from the host system using one or more dedicated hibernation write commands, wherein identifying the storage locations in the set comprises detecting the storage locations written to using the dedicated hibernation write commands.

8. The method according to claim 1, further comprising detecting that the host system is preparing to enter the hibernation state.

9. The method according to claim 8, further comprising, responsively to detecting that the host system is preparing to enter the hibernation state, switching to store the hibernation-related information using a high-speed storage configuration.

10. The method according to claim 8, wherein detecting that the host system is preparing to enter the hibernation state comprises detecting one or more dedicated hibernation write commands received from the host system.

11. The method according to claim 8, wherein detecting that the host system is preparing to enter the hibernation state comprises detecting one or more write commands to storage locations belonging to the hibernation storage space.

12. The method according to claim 8, wherein detecting that the host system is preparing to enter the hibernation state comprises receiving a notification from the host system indicating a preparation to enter the hibernation state.

13. The method according to claim 1, further comprising detecting that the host system is preparing to exit the hibernation state.

14. The method according to claim 13, wherein detecting that the host system is preparing to exit the hibernation state comprises detecting one or more read commands from storage locations belonging to the hibernation storage space.

15. The method according to claim 13, wherein detecting that the host system is preparing to exit the hibernation state comprises receiving a notification from the host system indicating a preparation to exit the hibernation state.

16. The method according to claim 1, further comprising copying valid data from the partially-programmed memory blocks in the user data storage space to the at least the portion of the hibernation storage space only responsively to verifying that the hibernation-related information is invalid.

17. The method according to claim 1, further comprising, after the host system exits from the hibernation state and retrieves the hibernation-related information from the non-volatile storage device, marking the hibernation-related information as invalid.

18. The method according to claim 1, further comprising, in preparation for entering the hibernation state, storing part of the hibernation-related information in the at least a portion of the hibernation storage space.

19. The method according to claim 1, further comprising writing user data at a first throughput, and, in preparation for entering the hibernation state, writing the hibernation-related information to the hibernation storage space at a second throughput, higher than the first throughput.

20. The method according to claim 1, further comprising, in preparation for entering the hibernation state, compressing the hibernation-related information and storing the compressed hibernation-related information in the hibernation storage space.

21. The method according to claim 1, further comprising receiving a notification from the host system indicating that the host system is preparing to enter the hibernation state, and vacating the at least a portion of the hibernation storage space in response to the notification.

22. Apparatus for data storage, comprising:

a non-volatile memory including multiple memory blocks; and

a memory controller coupled to the non-volatile memory and configured to;

store data for a host system that operates alternately in a normal state and a hibernation state;

allocate the multiple memory blocks as a user data storage space, over-provisioning memory, and to reserve a hibernation storage space in the non-volatile memory to store hibernation-related information in preparation for entering the hibernation state; and

while the host system is operating in the normal state, the memory controller is configured to allocate at least a portion of the hibernation storage space as over-provisioning memory, thereby allowing valid data to be copied from partially-programmed memory blocks in the user data storage space to the at least a portion of the hibernation storage space, and the valid data from the at least a portion of the hibernation storage space to be copied to the user data storage space subsequent to an erasure operation being performed one or more locations of the user data storage space.

23. The apparatus according to claim 22, wherein the memory controller is configured to allocate at least another portion of the hibernation storage space as a cache, and to cache user data accepted from the host system in the at least another portion of the hibernation storage space, and to subsequently copy the cached user data to storage locations outside the hibernation storage space.

24. The apparatus according to claim 23, wherein the memory controller is configured to cache the user data in the hibernation storage space at a first storage throughput, and to store the user data outside the hibernation storage space at a second storage throughput that is lower than the first storage throughput.

25. The apparatus according to claim 22, wherein a set of storage locations of the user data storage space is identified by the host system to serve as the hibernation storage space, and wherein the memory controller is configured to identify at least part of the storage locations in the set, and to manage the storage using the identified storage locations.

26. The apparatus according to claim 25, wherein the memory controller is configured to identify the storage locations in the set by receiving a notification from the host system indicative of the set of storage locations.

27. The apparatus according to claim 25, wherein the memory controller is configured to identify the storage locations in the set by automatically identifying a file holding the hibernation-related information in a file system of the host system.

28. The apparatus according to claim 25, wherein the memory controller is configured to receive the hibernation-related information from the host system using one or more dedicated hibernation write commands, and to identify the storage locations in the set by detecting the storage locations written to using the dedicated hibernation write commands.

29. The apparatus according to claim 22, wherein the memory controller is configured to detect that the host system is preparing to enter the hibernation state.

30. The apparatus according to claim 29, wherein the memory controller is configured to switch to store the hibernation-related information using a high-speed storage configuration responsively to detecting that the host system is preparing to enter the hibernation state.

31. The apparatus according to claim 29, wherein the memory controller is configured to detect that the host system is preparing to enter the hibernation state by detecting one or more dedicated hibernation write commands received from the host system.

32. The apparatus according to claim 29, wherein the memory controller is configured to detect that the host system is preparing to enter the hibernation state by detecting one or more write commands to storage locations belonging to the hibernation storage space.

33. The apparatus according to claim 29, wherein the memory controller is configured to detect that the host system is preparing to enter the hibernation state by receiving a notification from the host system indicating a preparation to enter the hibernation state.

34. The apparatus according to claim 22, wherein the memory controller is configured to detect that the host system is preparing to exit the hibernation state.

35. The apparatus according to claim 34, wherein the memory controller is configured to detect that the host system is preparing to exit the hibernation state by detecting one or more read commands from storage locations belonging to the hibernation storage space.

36. The apparatus according to claim 34, wherein the memory controller is configured to detect that the host system is preparing to exit the hibernation state by receiving a notification from the host system indicating a preparation to exit the hibernation state.

37. The apparatus according to claim 22, wherein the memory controller is configured to copy valid data from the partially-programmed memory blocks in the user data storage space to the at least the portion of the hibernation storage space only responsively to verifying that the hibernation-related information is invalid.

38. The apparatus according to claim 22, wherein, after the host system exits from the hibernation state and retrieves the hibernation-related information from the non-volatile storage device, the memory controller is configured to mark the hibernation-related information as invalid.

39. The apparatus according to claim 22, wherein, in preparation for entering the hibernation state, the memory controller is configured to store part of the hibernation-related information in the at least a portion of the hibernation storage space.

40. The apparatus according to claim 22, wherein the memory controller is configured to write user data at a first throughput, and to write the hibernation-related information to the hibernation storage space at a second throughput, higher than the first throughput.

41. The apparatus according to claim 22, wherein, in preparation for entering the hibernation state, the memory controller is configured to compress the hibernation-related information and store the compressed hibernation-related information in the hibernation storage space.

42. The apparatus according to claim 22, wherein the memory controller is configured to receive a notification from the host system indicating that the host system is preparing to enter the hibernation state, and to vacate the at least a portion of the hibernation storage space in response to the notification.