Cache write integrity logging

• US 7,937,524 B2
• Filed: 09/17/2007
• Issued: 05/03/2011
• Est. Priority Date: 06/27/2003
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Royer, Robert J. Jr., Coulson, Richard L.
• Primary Examiner(s): Nguyen; Hiep T
• Application Number:
  US11/856,258
• Publication Number:
  US 20080010401A1
• Time in Patent Office: 1,324 Days
• Field of Search: None
• US Class Current: 711/104
• CPC Class Codes: G06F 11/1417 Boot up procedures
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence

Abstract

An apparatus, as well as systems, methods, and articles can operate to record the address of write operations to a memory cached by a non-volatile cache prior to executing an operating system cache driver. In an embodiment, a non-volatile cache may be implemented by creating a device option read only memory (ROM), or modifying the associated computer basic input-output system (BIOS) to trap software interrupts associated with disk and other media access requests. Associated addresses, such as logical block addresses, can be stored in a log for data that is modified. The resulting log can be stored in a non-volatile medium, including the cache itself. If the available log space is not large enough to record all write activity prior to loading operating system drivers, a flag may be set to indicate the overrun condition.

Claims

1. A method occurring during a single power cycle of a non-volatile cache, comprising:

initializing a processor associated with the non-volatile cache;

recording an address of a write operation to a memory having information cached by the non-volatile cache, wherein recording occurs after initializing the processor; and

loading an operating system cache driver associated with the non-volatile cache, wherein recording occurs prior to loading the operating system cache driver.

2. The method of claim 1, wherein recording the address of the write operation further comprises:

recording the address in a log.

3. The method of claim 2, wherein the log is stored in a memory comprising at least one of a static random access memory (SRAM), a dynamic random access memory (DRAM), a flash memory, and a polymer ferroelectric RAM (PFRAM).

4. The method of claim 1, further comprising:

detecting the write operation.

5. The method of claim 4, wherein detecting the write operation further comprises:

trapping an interrupt request.

6. The method of claim 1, further comprising:

modifying data corresponding to the address of the write operation.

7. The method of claim 6, wherein modifying the data corresponding to the address of the write operation further comprises:

updating the data corresponding to the address of the write operation.

8. The method of claim 6, wherein modifying the data corresponding to the address of the write operation further comprises:

invalidating the data corresponding to the address of the write operation.

9. An article comprising a machine-accessible medium having associated data, wherein the data, when accessed, results in a machine performing:

initializing a processor associated with a non-volatile cache;

recording an address of a write operation to a memory having information cached by the non-volatile cache, wherein recording occurs after initializing the processor following a system shutdown or power failure, and;

loading an operating system cache driver associated with the non-volatile cache following said system shutdown or power failure, wherein recording occurs prior to loading the operating system cache driver.

10. The article of claim 9, wherein the data, when accessed, results in the machine performing:

recording the address of the write operation in a log.

11. The article of claim 10, wherein the log is included in a non-volatile memory.

12. The article of claim 10, wherein the data, when accessed, results in the machine performing:

setting a flag to indicate an overrun of the log.

13. The article of claim 12, wherein the data, when accessed, results in the machine performing:

invalidating the non-volatile cache if the flag is set.

14. An apparatus, comprising:

a processor;

a non-volatile cache associated with the processor; and

a memory to store an address associated with a write operation to a memory having information cached by the non-volatile cache, wherein the processor is configured to store the address after initializing the processor following a cycle of power to the non-volatile cache and prior to loading an operating system cache driver associated with the non-volatile cache, wherein loading occurs following the cycle of power to the non-volatile cache.

15. The apparatus of claim 14, wherein the address is a logical block address.

16. The apparatus of claim 14, wherein the memory to store an address comprises a non-volatile memory.

17. The apparatus of claim 14, further comprising:

a module to receive an interrupt request associated with the write operation.

18. The apparatus of claim 17, wherein the interrupt request is a basic input-output system Int13h request.

19. A system, comprising:

a non-volatile cache; and

a memory to store an address associated with a write operation to a memory having information cached by the non-volatile cache prior to loading an operating system cache driver associated with the non-volatile cache;

a processor coupled to the memory to store an address, the processor associated with the non-volatile cache, wherein the processor is configured to store the address after initializing the processor following a system shutdown or power failure and prior to loading the operating system cache driver following the system shutdown or power failure; and

a display coupled to the processor.

20. The system of claim 19, further comprising:

a module to receive an interrupt request associated with the write operation.

21. The system of claim 20, wherein the module is included in a device option memory.

22. The system of claim 20, wherein the module is included in a basic input-output system.

23. The system of claim 19, wherein the memory to store an address comprises a non-volatile memory to store a log including a plurality of memory addresses including the address of the write operation.