HOST CONTROL OF BACKGROUND GARBAGE COLLECTION IN A DATA STORAGE DEVICE

• US 20100287217A1
• Filed: 04/07/2010
• Published: 11/11/2010
• Est. Priority Date: 04/08/2009
• Status: Abandoned Application

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Borchers, Albert T., Swing, Andrew T., Sprinkle, Robert S.
• Application Number:
  US12/755,968
• Publication Number:
  US 20100287217A1
• Time in Patent Office: Days
• US Class Current: 707/813
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 2212/7208 Multiple device management, e.g. distributing data over multiple flash devices

Abstract

An apparatus includes a flash memory data storage device and a host operably coupled to the data storage device via an interface. The flash memory data storage device includes a plurality of memory chips. The host includes a host activity monitoring engine configured to monitor activity of the host and a garbage collection control engine configured to control the background garbage collection performed by the data storage device'"'"'s garbage collector.

Claims

1. A method of transferring data between a host and a memory device, the method comprising:

monitoring activity of the host; and

controlling background garbage collection of memory blocks of the memory device in response to the monitored activity.

2. The method of claim 1, wherein the memory device comprises flash memory chips.

3. The method of claim 1, wherein monitoring the activity of the host comprises monitoring a usage level of a processor of the host, the method further comprising:

determining that the usage level exceeds a predetermined level, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of cycles of a processor of the data storage device, which are devoted to background garbage collection in response to the determination that the usage level exceeds the predetermined level.

4. The method of claim 1, wherein monitoring the activity of the host comprises monitoring a rate of reading data from the memory device to the host, the method further comprising:

determining that the rate of reading data exceeds a predetermined rate, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises halting the background garbage collection while the rate of reading data exceeds the predetermined level.

5. The method of claim 1, wherein monitoring the activity of the host comprises monitoring a rate of reading data from the memory device to the host, the method further comprising:

determining that the rate of reading data exceeds a predetermined rate, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of effort devoted to background garbage collection in comparison to an amount of effort devoted to reading data from the memory device to the host while the rate of reading data exceeds the predetermined rate.

6. The method of claim 1, wherein monitoring the activity of the host comprises receiving a signal that certain read events will occur in which data will be read from the memory device to the host, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of effort devoted to background garbage collection in comparison to an amount of effort devoted to reading data from the memory device to the host in response to receipt of the signal.

7. The method of claim 1, wherein the memory device comprises a plurality of memory chips.

8. The method of claim 1, wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises:

monitoring, from a host device, write operations performed on a block of memory blocks of the memory device;

sending instructions from the host device to the memory device to perform background garbage collection on targeted memory blocks of the memory device;

limiting, at the host, background garbage collection below a threshold amount; and

then, at a later time,

allowing background garbage collection above the threshold amount.

9. The method of claim 1, wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises:

sending a signal from the host to the memory device to instruct a garbage collector of the memory device to limit background garbage collection below a threshold amount; and

then, at a later time,

sending a signal from the host to the memory device to instruct a garbage collector of the memory device that the limitation on background garbage collection has been ended.

10. The method of claim 9, further comprising:

determining that certain high priority read events are anticipated to occur, and

wherein the signal is based on the determination.

11. The method of claim 9, further comprising:

receiving a query for one or more documents;

wherein the monitored activity includes retrieving data from the memory device in response to the query; and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises blocking the background garbage collection while the data is retrieved from the memory device.

12. An apparatus comprising:

a flash memory data storage device including;

a plurality of memory chips;

a host operably coupled to the data storage device via an interface, the host including;

a host activity monitoring engine configured to monitor activity of the host; and

a garbage collection control engine configured to control the background garbage collection performed by the data storage device'"'"'s garbage collector.

13. The apparatus of claim 12, wherein monitoring the activity of the host comprises monitoring a usage level of a processor of the host, the host activity monitoring engine being further configured to:

determine that the usage level exceeds a predetermined level, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of cycles of a processor of the data storage device, which are devoted to background garbage collection in response to the determination that the usage level exceeds the predetermined level.

14. The apparatus of claim 12, wherein monitoring the activity of the host comprises monitoring a rate of reading data from the memory device to the host and determining that the rate of reading data exceeds a predetermined rate, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises halting the background garbage collection while the rate of reading data exceeds the predetermined level.

15. The apparatus of claim 12, wherein monitoring the activity of the host comprises monitoring a rate of reading data from the memory device to the host and determining that the rate of reading data exceeds a predetermined rate, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of effort devoted to background garbage collection in comparison to an amount of effort devoted to reading data from the memory device to the host while the rate of reading data exceeds the predetermined rate.

16. The apparatus of claim 12, wherein monitoring the activity of the host comprises receiving a signal that certain read events will occur in which data will be read from the memory device to the host, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of effort devoted to background garbage collection in comparison to an amount of effort devoted to reading data from the memory device to the host in response to receipt of the signal.

17. The apparatus of claim 12, wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises:

monitoring, from a host device, write operations performed on a block of memory blocks of the memory device;

sending instructions from the host device to the memory device to initiate background garbage collection on targeted memory blocks of the memory device;

limiting, at the host, background garbage collection below a threshold amount; and

then, at a later time,

allowing background garbage collection above the threshold amount.

18. The apparatus of claim 17,

wherein the host further includes a processor configured to determine that certain high priority read events are anticipated to occur, and

wherein the limitation of background garbage collection below the threshold amount is based on the determination.

19. The apparatus of claim 17,

wherein the host further comprises a query handler adapted to receive a query for one or more documents;

wherein the monitored activity includes retrieving data from the memory device in response to the query; and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises blocking the background garbage collection while the data is retrieved from the memory device.

20. The apparatus of claim 12, wherein the memory device comprises a plurality of memory chips.

21. The apparatus of claim 20, wherein controlling the background garbage collection includes differentially controlling the amount of background garbage collection on different ones of the plurality of memory chips.

22. An apparatus comprising:

a flash memory data storage device including;

a plurality of memory chips;

a garbage collector configured to perform background garbage collection of memory blocks of the memory device;

a host operably coupled to the data storage device via an interface, the host including;

a host activity monitoring engine configured to monitor activity of the host; and

a garbage collection control engine configured to control the background garbage collection performed by the data storage device'"'"'s garbage collector.

23. The apparatus of claim 22, wherein monitoring the activity of the host comprises monitoring a usage level of a processor of the host, the host activity monitoring engine being further configured to:

determine that the usage level exceeds a predetermined level, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of cycles of a processor of the data storage device, which are devoted to background garbage collection in response to the determination that the usage level exceeds the predetermined level.

24. The apparatus of claim 22, wherein monitoring the activity of the host comprises monitoring a rate of reading data from the memory device to the host and determining that the rate of reading data exceeds a predetermined rate, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises halting the background garbage collection while the rate of reading data exceeds the predetermined level.

25. The apparatus of claim 22, wherein monitoring the activity of the host comprises monitoring a rate of reading data from the memory device to the host and determining that the rate of reading data exceeds a predetermined rate, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of effort devoted to background garbage collection in comparison to an amount of effort devoted to reading data from the memory device to the host while the rate of reading data exceeds the predetermined rate.

26. The apparatus of claim 22, wherein monitoring the activity of the host comprises receiving a signal that certain read events will occur in which data will be read from the memory device to the host, and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises limiting an amount of effort devoted to background garbage collection in comparison to an amount of effort devoted to reading data from the memory device to the host in response to receipt of the signal.

27. The apparatus of claim 22, wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises:

sending a signal from the host to the memory device to instruct a garbage collector of the memory device to limit background garbage collection below a threshold amount; and

then, at a later time,

sending a signal from the host to the memory device to instruct a garbage collector of the memory device that the limitation on background garbage collection has been ended.

28. The apparatus of claim 27,

wherein the host further includes a processor configured to determine that certain high priority read events are anticipated to occur, and

wherein the signal is based on the determination.

29. The apparatus of claim 27,

wherein the host further comprises a query handler adapted to receive a query for one or more documents;

wherein the monitored activity includes retrieving data from the memory device in response to the query; and

wherein controlling background garbage collection of memory blocks of the memory device in response to the monitored activity comprises blocking the background garbage collection while the data is retrieved from the memory device.

30. The apparatus of claim 22, wherein the memory device comprises a plurality of memory chips.

31. The apparatus of claim 30, wherein controlling the background garbage collection performed by the data storage device'"'"'s garbage collector includes differentially controlling the amount of background garbage collection on different ones of the plurality of memory chips performed by the data storage device'"'"'s garbage collector.