System to improve memory failure management and associated methods

• US 8,352,806 B2
• Filed: 01/31/2008
• Issued: 01/08/2013
• Est. Priority Date: 01/31/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gollub, Marc A., Lastras-Montano, Luis A., Patel, Piyush C., Retter, Eric E., Trager, Barry M., Winograd, Shmuel, Wright, Kenneth L.
• Primary Examiner(s): Baderman, Scott
• Assistant Examiner(s): KUDIRKA, JOSEPH R
• Application Number:
  US12/023,498
• Publication Number:
  US 20100293437A1
• Time in Patent Office: 1,804 Days
• Field of Search: 714/6.1, 714/6.11, 714/6.12, 714/6.13, 714/6.2, 714/6.24, 714/6.31, 714/42, 714 52- 54, 714/723, 714/759, 714/763, 714/784, 714/785, 714/30, 714/36, 713/1, 713/2, 709/224
• US Class Current: 714/54
• CPC Class Codes: G06F 11/1048 using arrangements adapted for a specific error detection or correction feature
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/154 Error and erasure correction, e.g. by using the error and erasure locator or Forney polynomial
• CPC Class Codes: H03M 13/1545 Determination of error locations, e.g. Chien search or other methods or arrangements for the determination of the roots of the error locator polynomial
• CPC Class Codes: H03M 13/353 Adaptation to the channel
• CPC Class Codes: H03M 13/3707 Adaptive decoding and hybrid decoding, e.g. decoding methods or techniques providing more than one decoding algorithm for one code
• CPC Class Codes: H03M 13/6511 Support of multiple decoding rules, e.g. combined MAP and Viterbi decoding

Abstract

A system to improve memory failure management may include memory, and an error control decoder to determine failures in the memory. The system may also include an agent that may monitor failures in the memory. The system may further include a table where the error control decoder may record the failures, and where the agent can read and write to.

Claims

1. A system to improve memory failure management, the system comprising:

memory;

an error control decoder to determine failures in said memory;

an agent to monitor failures in said memory, said agent comprising firmware and is autonomous from the error control decoder; and

a table where said error control decoder records the determined failures as error control decoder entries, and where said agent reads from and writes to, including changing said error control decoder entries in said table, without being based upon said error control decoder failure determinations.

2. The system of claim 1 wherein said error control decoder updates said table upon finding new persistent failures not previously found in said table.

3. The system of claim 1 wherein said error control decoder uses information stored in said table to correct errors associated with persistent failures.

4. The system of claim 1 wherein said error control decoder communicates with said agent'"'"'s firmware when said error control decoder updates said table.

5. The system of claim 1 wherein said error control decoder'"'"'s updates of said table are disabled.

6. The system of claim 1 wherein said agent'"'"'s firmware updates said table with new persistent failure information if said agent'"'"'s firmware encounters a new persistent failure not already identified in said table.

7. The system of claim 1 wherein said agent'"'"'s firmware updates said table if a failure identified in said table is no longer persistent.

8. The system of claim 1 wherein said table contains information about error control symbols with persistent failures and wherein the information is stored in at least one of Galois Field format and as a numeric index offset.

9. The system of claim 1 wherein said memory is partitioned in memory ranks and the memory ranks are comprised of memory chips.

10. The system of claim 9 wherein persistent failures are full memory chip failures or failures of a portion of any of said memory chips.

11. The system of claim 1 wherein said agent'"'"'s firmware request to write to said table fails resulting in a write request failure notification being sent to said agent'"'"'s firmware.

12. A method to improve memory failure management, the method comprising:

determining failures in memory by an error control decoder;

recording the determined failures in a table as error control decoder entries by the error control decoder; and

reading from and writing to the table by an agent that is autonomous from the error control decoder and that monitors failures in the memory including changing said error control decoder entries in said table without being based upon said error control decoder failure determinations, and said agent comprises firmware.

13. The method of claim 12 wherein the error control decoder updates the table upon finding new persistent failures not previously found in the table.

14. The method of claim 12 wherein the error control decoder uses information stored in the table to correct errors associated with persistent failures.

15. The method of claim 12 wherein the error control decoder'"'"'s updates of the table are disabled.

16. A computer program product embodied in a non-transitory computer-usable storage medium comprising:

program code embodied in the computer-usable storage medium to improve memory failure management, the program code configured to;

determine failures in memory by an error control decoder;

record the determined failures in a table as error control decoder entries by the error control decoder; and

read from and write to the table by an agent that is autonomous from the error control decoder and that monitors failures in the memory including changing said error control decoder entries in said table without being based upon said error control decoder failure determinations, and said agent comprises firmware.

17. The computer program product of claim 16 further comprising program code configured to:

update the table by the error control decoder upon finding new persistent failures not previously found in the table.

18. The computer program product of claim 16 further comprising program code configured to:

use information stored in the table by the error control decoder to correct errors associated with persistent failures.

19. The computer program product of claim 16 further comprising program code configured to:

disable updates of the table by the error control decoder.