MULTIPATH POWER MANAGEMENT

• US 20100199116A1
• Filed: 02/05/2009
• Published: 08/05/2010
• Est. Priority Date: 02/05/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: Copas, Kevin, Qi, Yanling
• Granted Patent: US 8,127,165 B2
• Time in Patent Office: Days
• US Class Current: 713/324
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Disclosed is a method of controlling power. Multiple paths via multiple I/O ports couple a server to a storage array. When I/O loads are low, it is determined if an I/O port may be deactivated and placed in a power saving mode. An I/O port may not be deactivated if deactivating that I/O port will affect a high-availability requirement or a performance requirement. Requests are stopped from being sent to an I/O port to be deactivated. When the port to be deactivated becomes idle, the I/O port is placed in a power saving mode. When I/O loads increase to a point where it is necessary to reactivate the I/O port, the I/O port is activated.

Claims

1. A method of controlling power, comprising:

communicating with an external device via at least a first I/O port and a second I/O port;

determining that a usage indicator associated with at least said first I/O port and said second I/O port satisfies a first usage criteria;

in response to said usage indicator satisfying said first usage criteria, determining that said first I/O port may be deactivated; and

,

deactivating said first I/O port.

2. The method of claim 1, wherein determining that said first I/O port may be deactivated is based on a high availability criteria.

3. The method of claim 1, wherein determining that said first I/O port may be deactivated is based on a first usage indicator associated with said first I/O port and a second usage indicator associated with said second I/O port.

4. The method of claim 1, further comprising:

re-routing I/O requests destined for said first I/O port to said second I/O port.

5. The method of claim 4, further comprising:

waiting for said first I/O port to become idle before deactivating said first I/O port.

6. The method of claim 1, wherein said first I/O port is deactivated by instructing said first I/O port to change from a first PCI device power state to a second PCI device power state.

7. The method of claim 1, further comprising:

determining that said usage indicator satisfies a second usage criteria;

in response to said usage indicator satisfying said second usage criteria, activating said first I/O port.

8. The method of claim 7, wherein said first I/O port is deactivated by instructing said first I/O port to change from a first PCI device power state to a second PCI device power state.

9. The method of claim 8, wherein said first I/O port is activated by instructing said first I/O port to change from said second PCI device power state to said first PCI device power state.

20. The computer readable medium of claim 1, wherein said first I/O port is deactivated by instructing said first I/O port to change from a first PCI device power state to a second PCI device power state.

10. A power saving system, comprising:

a plurality of I/O ports coupled via a plurality of paths to an external I/O device, said plurality of I/O ports comprising a first I/O port and a second I/O port;

a multi-path manager that routes I/O requests to at least said first I/O port and said second I/O port;

a power manager monitoring a total I/O bandwidth associated with said plurality of I/O ports, said power manager instructing said multi-path manager to stop routing I/O requests to said first I/O port in response to said total I/O bandwidth satisfying a bandwidth criteria; and

,

an I/O port manager that, in response to said first I/O port becoming idle, instructs said first I/O port to enter a power saving mode.

11. The power saving system of claim 10, wherein said multi-path manager determines whether at least two paths of said plurality of paths to said external I/O device will still exist if said first I/O port is deactivated.

12. The power saving system of claim 10, wherein said I/O port manager instructs said first I/O port to enter a power saving mode by using a PCI device power state.

13. The power saving system of claim 10, wherein said power manager in response to said total I/O bandwidth satisfying a second bandwidth criteria, instructs said multi-path manager to route I/O requests to said first I/O port and said I/O port manager instructs said first I/O port to exit said power saving mode.

14. The power saving system of claim 10, wherein said multi-path manager selects said first I/O port to be deactivated based on based on a first usage indicator associated with said first I/O port and a second usage indicator associated with said second I/O port.

15. A computer readable medium having instructions stored thereon for controlling power that, when executed by a computer, at least instruct the computer to:

communicate with an external device via at least a first I/O port and a second I/O port;

determine that a usage indicator associated with at least said first I/O port and said second I/O port satisfies a first usage criteria;

in response to said usage indicator satisfying said first usage criteria, determine that said first I/O port may be deactivated; and

,

deactivate said first I/O port.

16. The computer readable medium of claim 15, wherein determining that said first I/O port may be deactivated is based on a high availability criteria.

17. The computer readable medium of claim 15, wherein determining that said first I/O port may be deactivated is based on a first usage indicator associated with said first I/O port and a second usage indicator associated with said second I/O port.

18. The computer readable medium of claim 15, wherein the computer is further instructed to:

re-route I/O requests destined for said first I/O port to said second I/O port.

19. The computer readable medium of claim 18, wherein the computer is further instructed to:

wait for said first I/O port to become idle before deactivating said first I/O port.