SYSTEM AND METHOD FOR PREDICTING AND IMPROVING BOOT-UP SEQUENCE

• US 20140281458A1
• Filed: 08/07/2013
• Published: 09/18/2014
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Walvekar, Ninad, Babykannan, Pranesh, Ravimohan, Narendhiran Chinnaanangur, Kannappan, Vithya, Nedunchezhiyan, Saranya
• Granted Patent: US 9,110,677 B2
• Time in Patent Office: Days
• US Class Current: 713/2
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 2212/602 Details relating to cache prefetching
• CPC Class Codes: G06F 2212/6026 Prefetching based on access pattern detection, e.g. stride based prefetch
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57
• CPC Class Codes: G06F 9/4403 Processor initialisation
• CPC Class Codes: G06F 9/4418 Suspend and resume; Hibernate and awake

Abstract

A method for optimizing a boot up sequence includes, during a host idle time or during data transfer: obtaining a predicted read address from the a prediction table, prefetching from the non-volatile data store, and saving the prefetched data in memory. Also included is receiving a current read command issued by the host and if the read address matches the predicted read address, providing to the host the prefetched data saved in temporary memory, and indicating a match. If a match is not indicated, obtaining current data from the non-volatile data store corresponding to the read address of the current read command, and providing the current data to the host. If a match was not indicated, searching the data prediction table for the predicted read address that matches the read address corresponding to the current read command, and if found in the data prediction table, recording the offset value.

Claims

1. A method for optimizing a boot up sequence of a computer system, comprising:

in a memory system controller having a non-volatile data store and a data prediction table, the controller in communication with a host device, the method comprising;

during a host idle time or during a data transfer corresponding to a prior host read command;

obtaining a predicted read address from the data prediction table based on a previously determined offset value;

prefetching from the non-volatile data store, data corresponding to the read address obtained from the data prediction table;

saving the prefetched data in temporary memory;

receiving a current read command issued by the host;

if the read address corresponding to the current read command matches the predicted read address, providing to the host the prefetched data saved in temporary memory, and indicating a match;

if a match is not indicated, obtaining current data from the non-volatile data store corresponding to the read address of the current read command, and providing the current data to the host; and

if a match was not indicated, searching the data prediction table for the predicted read address that matches the read address corresponding to the current read command, and if found in the data prediction table, recording the offset value.

2. The method according to claim 1, further comprising initializing the data prediction table by recording a sequence of read commands issued by the host device to the memory system controller, the sequence of read commands corresponding to a second boot up sequence.

3. The method according to claim 1, further comprising recording in the data prediction table a sequence of read commands issued by the host, including memory addresses associated with each read command and a corresponding data count or sector count.

4. The method according to claim 2, further comprising detecting a valid boot up sequence after initialization of the data prediction table.

5. The method according to claim 4, wherein the valid boot up sequence corresponds to a power-on reset or a wake-up from hibernation.

6. The method according to claim 4, wherein the valid boot up sequence excludes soft boot up sequences and recovery from a stand-by mode.

7. The method according to claim 1, wherein the match includes an address match and a corresponding data count or sector count match.

8. The method according to claim 1, wherein the offset value corresponds to a difference in location in the data prediction table between the predicted read address and the read address of the current read command when no match is initially found.

9. The method according to claim 1, wherein the predicted read address obtained from the data prediction table is a read address that is probabilistically predicted to match the current read address issued by the host.

10. The method according to claim 1, wherein the computer system is a mobile telephone, a wireless mobile device, or a personal computer.

11. The method according to claim 1, wherein the memory system controller controls a solid state disk drive or a rotating magnetic disk drive.

17. The method according to claim 1, wherein the offset value corresponds to a difference in location in the data prediction table between the predicted read address and the read address of the current read command when no match is initially found.

12. A method for optimizing a boot up sequence of a computer system comprising:

in a memory system controller having a non-volatile data store and a data prediction table, the controller in communication with a host device, the method comprising;

initializing the data prediction table by recording a sequence of read commands issued by the host device to the memory system controller, the sequence of read commands corresponding to a second boot up sequence;

detecting a valid boot up sequence after initialization of the data prediction table;

during a host idle time or during a data transfer corresponding to a prior host read command;

obtaining a predicted read address from the data prediction table based on a previously determined offset value;

prefetching from the non-volatile data store, data corresponding to the read address obtained from the data prediction table;

saving the prefetched data in temporary memory;

receiving a current read command issued by the host;

if the read address corresponding to the current read command matches the predicted read address, providing the prefetched data saved in temporary memory to the host, and indicating a match;

if a match is not indicated, obtaining current data from the non-volatile data store corresponding to the read address of the current read command, and providing the current data to the host; and

if a match was not indicated, searching the data prediction table for the predicted read address that matches the read address corresponding to the current read command, and if found in the data prediction table, recording an offset value.

13. The method according to claim 12, further comprising recording in the data prediction table a sequence of read commands issued by the host, including memory addresses associated with each read command and a corresponding data count or sector count.

14. The method according to claim 12, wherein the valid boot up sequence corresponds to a power-on reset or a wake-up from hibernation.

15. The method according to claim 13, wherein the valid boot up sequence excludes soft boot up sequences and recovery from a stand-by mode.

16. The method according to claim 13, wherein the match includes an address match and a corresponding data count or sector count match.

18. A memory storage system operative to interface with a host, comprising:

a memory system controller;

a non-volatile data store operatively coupled to the memory system controller;

a data prediction table accessible by the memory system controller;

the memory system controller configured to;

initialize the data prediction table by recording a sequence of read commands issued by the host device to the memory system controller, the sequence of read commands corresponding to a second boot up sequence;

detect a valid boot up sequence after initialization of the data prediction table;

during a host idle time or during a data transfer corresponding to a prior host read command;

obtain a predicted read address from the data prediction table based on a previously determined offset value;

prefetch from the non-volatile data store, data corresponding to the read address obtained from the data prediction table;

save the prefetched data in temporary memory;

receive a current read command issued by the host;

if the read address corresponding to the current read command matches the predicted read address, provide the prefetched data saved in temporary memory to the host, and indicate a match;

if a match is not indicated, obtain current data from the non-volatile data store corresponding to the read address of the current read command, and provide the current data to the host; and

if a match was not indicated, search the data prediction table for the predicted read address that matches the read address corresponding to the current read command, and if found in the data prediction table, recording an offset value.