System and method for efficient power throttling in multiprocessor chip

• US 7,596,707 B1
• Filed: 05/06/2005
• Issued: 09/29/2009
• Est. Priority Date: 05/06/2005
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Vemula, Sunil K.
• Primary Examiner(s): Lee; Thomas
• Assistant Examiner(s): Abbaszadeh; Jaweed A
• Application Number:
  US11/123,760
• Time in Patent Office: 1,607 Days
• Field of Search: 711/105, 711/167, 713/300, 713/320
• US Class Current: 713/320
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3275 Power saving in memory, e.g. RAM, cache
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A method for limiting power consumption in a multiprocessor chip is provided. In this method, a read or write request is received by the memory controller, which controls a memory that is external to the multiprocessor chip. The memory controller includes a bank counter that keeps track of the number of read or write requests received by the memory controller. At every clock cycle, the bank counter value is compared with a threshold value to determine whether the counter value is equal to the threshold value. If the bank counter value is determined to be equal to the threshold value, then any subsequent incoming read or write requests are blocked. The bank counter value is incremented each time a read or write request is sent to the memory.

Claims

1. A system for limiting power consumption in a memory attached to a multiprocessor chip comprising:

a multiprocessor chip;

a plurality of memory controllers inside the multiprocessor chip in communication with a memory, wherein each memory controller includes,

a bank counter logic configured to increment a local bank counter in response to a read or write request, the local bank counter indicating how many memory banks are open in the memory by the each memory controller;

total bank counter logic configured to increment a total bank counter value, the total bank counter value indicating a total number of banks open by all the memory controllers;

a time counter logic configured to keep track of time in increments of a set time interval; and

a throttling logic configured to block the read or write request received subsequent to the total bank counter logic reaching a threshold value, the blocking the read or write request including temporarily storing the read or write request, and when terminating the blocking, resuming the read or write requests beginning with the at least one temporarily stored read or write requests;

wherein a signal is sent to the memory controllers to increment the total bank counter values each time a bank is open by any of the memory controllers.

2. A system of claim 1 further comprising:

a reset logic configured to reset the total bank counter value and the local bank counter when the time is equal to or greater than the set time interval.

3. A system of claim 2, wherein the plurality of processors are multithreaded processors.

4. A system of claim 1, wherein the memory is a dual-in-line memory module (DIMM).

5. A system of claim 1, further comprising:

input/output logic through which the memory controller communicates with the memory.

6. A system of claim 5, wherein the input/output logic is configured to generate drivers that drive the memory.

7. A method for limiting power consumption in a multiprocessor chip having integrated memory controllers, the method comprising:

receiving a read or write request at a particular memory controller, wherein each memory controller has a local bank counter indicating how many memory banks are open in the memory by the each memory controller;

incrementing the local bank counter at the particular memory controller;

incrementing a total bank counter value at each memory controller, the total bank counter value indicating a total number of banks open by all the memory controllers; and

blocking the read or write request received by the particular memory controller subsequent to the total bank counter logic reaching a threshold value, the blocking the read or write request including temporarily storing the read or write request, and when terminating the blocking, resuming the read or write requests beginning with the at least one temporarily stored read or write requests;

wherein a signal is sent to the plurality of memory controllers to increment the total bank counter values each time a bank is open by any of the memory controllers.

8. A method of claim 7, further comprising:

resetting a time counter.

9. A method of claim 8, further comprising:

determining if a current value of the time counter is equal to or greater than a predetermined time interval, and if the current value of the time counter is determined to be equal to or greater than the time interval, the method including,

resetting the total bank counters and the local bank counters; and

resetting the time counter.

10. A method of claim 9, wherein blocking the read or write request includes,

discontinuing issuing activation commands until resetting the time counter.

11. A method of claim 10, wherein the blocking the read or write request terminates after resetting the time counter.

12. A method of claim 7, further comprising:

determining whether a set time interval has expired.

13. A method of claim 12, wherein the set time interval is determined to have expired, then the method includes,

resetting the total bank counter value and the local bank counter.

14. A method of claim 13, wherein the blocking the read or write request terminates after resetting the total bank counter value.

15. A computer program embedded in a tangible computer-readable storage medium, when executed by one or more processors, for limiting power consumption in a multiprocessor chip having integrated memory controllers, the computer program comprising:

program instructions for receiving a read or write request at a particular memory controller, wherein each memory controller has a local bank counter indicating how many memory banks are open in the memory by the each memory controller;

program instructions for incrementing the local bank counter at the particular memory controller;

program instructions for incrementing a total bank counter value at each memory controller, the total bank counter value indicating a total number of banks open by all the memory controllers; and

program instructions for blocking the read or write request received by the particular memory controller subsequent to the total bank counter logic reaching a threshold value, the blocking the read or write request including temporarily storing the read or write request, and when terminating the blocking, resuming the read or write requests beginning with the at least one temporarily stored read or write requests;

wherein a signal is sent to the plurality of memory controllers to increment the total bank counter values each time a bank is open by any of the memory controllers.

16. The computer program embedded in a computer-readable storage medium of claim 15, further comprising:

program instructions for resetting a time counter.

17. The computer program embedded in a computer-readable storage medium of claim 16, further comprising:

program instructions for determining if a current value of the time counter is equal to or greater than a predetermined time interval, and if the current value of the time counter is determined to be equal to or greater than the time interval, the program instructions including,

program instructions for resetting the total bank counters and the local bank counters; and

program instructions for resetting the time counter.

18. The computer program embedded in a computer-readable storage medium of claim 17, wherein the program instructions for blocking the read or write request include,

program instructions for discontinuing issuing activation commands until resetting the time counter.

19. The computer program embedded in a computer-readable storage medium of claim 18, wherein the blocking the read or write request terminates after resetting the time counter.