System and intelligent dock using a symmetric extended bus bridge and method therefor

• US 6,675,237 B1
• Filed: 08/07/2000
• Issued: 01/06/2004
• Est. Priority Date: 08/07/2000
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schneider, Bengt-Olaf, Asaad, Sameh W., Dono, Nicholas R., Mandese, Ernest Nelson, Warren, Kevin W.
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Mai, Rijue
• Application Number:
  US09/633,826
• Time in Patent Office: 1,247 Days
• Field of Search: 710/1, 710/5, 710/18, 710/20, 710/41, 710/105, 710/106, 710/15, 710/31, 709/200, 709/201, 709/202-203, 709/212, 709/213-216, 709/238, 712/225
• US Class Current: 710/41
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence

Abstract

A computer network system includes a plurality of computers each including a central processing unit (CPU), a memory and at least one peripheral device, a connection fabric having selectable first and second sides, the first side being coupled to a first computer of the plurality of computers and the second side being coupled to at least a second computer of the plurality of computers. Each of the first and second computers performs a negotiation to determine which one of the first and second computers controls resources of the other of the first and second computers.

Claims

1. A computer system, comprising:

a plurality of computers each including a central processing unit (CPU), a memory and at least one peripheral device;

a connection fabric having selectable first and second sides, said first side being coupled to a first computer of said plurality of computers and said second side being coupled to at least a second computer;

a dock containing one of said first and second computers, and

a mobile unit containing the other of said first and second computers,

wherein said first and second computers negotiate to decide which of said first and second computers should suspend control and which of said first and second computers should take ownership of combined resources in said dock and on said mobile unit.

2. The system according to claim 1, wherein all but one computer of said plurality of computers grants access to its memory and peripheral device to a particular one of the plurality of computers.

3. The system according to claim 2, wherein the plurality of computers negotiate which computers will grant access and which computers will gain access to the other computers'"'"' memory and peripheral device.

4. The system according to claim 3, wherein the negotiation occurs over a connection other than the connection fabric.

5. The system according to claim 3, wherein the negotiation occurs through out-of-band signaling on the connection fabric.

6. The system according to claim 1, wherein the connection fabric comprises a network connection.

7. The system according to claim 1, wherein the connection fabric comprises a symmetric split bridge.

8. The system according to claim 1, wherein said negotiation determines a master computer and a set of slave computers,

said master computer controlling resources of all of said plurality of computers.

9. The system according to claim 8, wherein a computer other than said master computer is designated as a slave computer.

10. The system according to claim 8, wherein a set of slave computers includes a plurality of computers other than said master computer.

11. The system according to claim 1, wherein upon designation of a master computer, remaining ones of said plurality of computers no longer control their own resources such that all resources on primary and secondary busses are available to the computer designated as said master computer.

12. The system according to claim 1, wherein said connection fabric comprises a symmetric bridge for selectively swapping primary and secondary roles under CPU control.

13. The system according to claim 1, wherein one of said first and second computers resides in a mobile unit and the other of said first and second computers resides in a dock for being selectively coupled to said mobile unit.

14. The system according to claim 13, wherein said dock is operable in one of a plurality of active states, with or without said mobile unit being received in said dock.

15. The system according to claim 13, wherein in an undocked state, the mobile unit CPU and the dock CPU are active, such that each functions independently.

16. The system according to claim 13, wherein in a docked state, either of said mobile unit CPU and said dock CPU is in an active state.

17. A network system, comprising:

a plurality of computers including a first computer coupled to at least one other computer,

each of said computers including a module for negotiating which one of the computers will be a primary computer, remaining ones of the computers being set as secondary computers, such that said primary computer controls resources of said primary computer and said secondary computers,

wherein each one of said plurality of computers negotiates to decide which of said plurality of computers should suspend control and which should take ownership of the combined resources of said primary computer and said secondary computers.

18. A method of forming a computer network having a plurality of computers, comprising:

connecting a first computer to at least one other computer; and

negotiating by said first computer and said at least one other computer, to determine which one of said computers will be a primary computer, remaining ones of said plurality of computers being set as secondary computers, such that said primary computer controls resources of said primary computers and said secondary computers,

wherein said secondary computers suspend control after being set as secondary computers.

19. A method of performing a negotiation by a plurality of computers, comprising:

coupling a first computer to at least a second computer;

exchanging and comparing a capability metric of said first computer with that of said second computer; and

based on said comparing, determining which of said first and second computers has access to a primary bus and which of said first and second computers will be limited to a secondary bus,

wherein a central processing unit (CPU) processor of said computer having the highest capability metric is designated as a master computer and becomes an active CPU, and all others suspend, such that one CPU decides to suspend after setting its side of the bridge as a secondary bus and the other side stays active and sets its side of the bridge as a primary bus.

20. The method according to claim 19, wherein said capability metric includes at least one of a plurality of computer performance measurements.

21. The method according to claim 19, wherein said capability metric further includes a random number for use if a tie results in said comparing.

22. The method according to claim 20, wherein a weighted average of said plurality of performance measurements is used.

23. The method according to claim 19, wherein the active CPU has access to all resources on the primary and secondary busses.

24. A dock for selectively receiving a mobile computer unit, said dock comprising:

a central processing unit (CPU);

a memory coupled to said CPU;

at least one peripheral device for being controlled by said CPU; and

a connection fabric having selectable first and second sides, said first side being coupled to said CPU and said second side being coupled to said mobile computer unit,

wherein said CPU performs a negotiation to determine whether the CPU of the dock will control resources of the mobile computer unit, and

wherein, when said negotiation determines the CPU of the dock controls resources of the mobile computer unit, said mobile computer unit suspends control after setting an access to said second side.

25. A programmable storage device, readable by a machine, tangibly embodying instructions to perform a method for performing a negotiation by a plurality of computers, said method comprising:

coupling a first computer to at least a second computer;

exchanging and comparing a capability metric of said first computer with that of said second computer; and

based on said comparing, determining which of said first and second computers has access to a primary bus and which said first and second computers will be limited to a secondary bus,

wherein said one of said first and second computers limited to said secondary bus, suspends control after setting an access to said secondary bus.

26. A programmable storage device, readable by a machine, tangibly embodying instructions to perform a method for forming a computer network having a plurality of computers, said method comprising:

connecting a first computer to at least one other computer; and

negotiating by said first computer and said at least one other computer, to determine which one of said computers will be a primary computer, remaining ones of said plurality of computers being set as secondary computers, such that said primary computer controls resources of said primary computers and said secondary computers,

wherein said remaining ones of said plurality of computers suspend control after setting themselves to be secondary computers.

27. A computer system, comprising:

a plurality of computers each including a central processing unit (CPU), a memory and at least one peripheral device; and

a connection fabric having selectable first and second sides,

said first side being coupled to a first computer of said plurality of computers and said second side being coupled to at least a second computer,

each of said first and second computers performing a negotiation to determine which computer in the connecting computers will become a primary computer connected to a primary bus and will have control over combined resources of its own and the other of said first and second computers.

28. The system of claim 27, wherein the first and second computers are selectively enabled as the primary and secondary sides of the bridge, such that roles of said first and second computers are unfixed and each side of the connection fabric is equally operable as the primary side or as the secondary side, thereby enabling switching of the bus roles from the primary to the secondary and vice versa,

wherein the connection fabric splits the primary side from the secondary side.