Connection management mechanism

• US 7,826,349 B2
• Filed: 05/30/2006
• Issued: 11/02/2010
• Est. Priority Date: 05/30/2006
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Draggon, David A., Kaur, Sumeet
• Primary Examiner(s): Tsai; Henry W
• Assistant Examiner(s): Snyder; Steven G
• Application Number:
  US11/444,756
• Publication Number:
  US 20080005314A1
• Time in Patent Office: 1,617 Days
• Field of Search: 710/22, 710/36, 709/224, 709/223, 370/229, 370/230
• US Class Current: 370/229
• CPC Class Codes: G06F 13/387 for adaptation of different data processing systems to different peripheral devices, e.g. protocol converters for incompatible systems, open system

Abstract

A host device is disclosed. The host device includes a receive frame and primitive sequence processor and a connection manager to open a connection with a target device based on a probability of a blocked pathway.

Claims

1. An apparatus comprising:

a connection manager to determine, based upon a first computed probability of a first blocked pathway, when to allocate to a first initiator a connection with a target device, the first computed probability being computed after discovery of the target device by a host device, the first computed probability being determined by the connection manager and being directly proportional to a number of links in the pathway, the computed probability involving a potential connection collision with a second initiator requesting to connect to the target device, the connection manager to allocate the connection to the first initiator when the first computed probability of the first blocked pathway is higher than a second computed probability of a second blocked pathway between the second initiator and the target device.

2. The apparatus of claim 1 wherein the connection manager maintains an open connection to the target device if additional data is to be transmitted to the target device and there is no competing request to access the target device.

3. The apparatus of claim 2 wherein the connection manager closes the connection with the target device upon detecting that there is a competing request to access the target device and the competing request has a higher probability of a blocked pathway than the connection being serviced.

4. The apparatus of claim 2 wherein the connection manager maintains the open connection to the target device if there is a competing request to access the target device and the competing request has a lower probability of a blocked pathway connection being serviced.

5. The apparatus of claim 2 wherein the connection manager comprises a timer to track the time the connection is open with the target device.

6. The apparatus of claim 5 wherein the connection with the target device is closed if there is no competing request to access the target device and the timer has expired.

7. A method comprising:

determining, based upon a first computed probability of a first blocked pathway, when to establish a connection between a host device and a target device via a connection manager at the host device based upon a probability of a blocked pathway value received at the connection manager, the first computed probability being computed after discovery of the target device by the host device;

transferring data between the host device and the target device; and

determining if additional data is to be transferred between the host device and the target device;

determining if a competing request to access the target device has been received if additional data is to be transferred between the host device and the target device; and

maintaining an open connection between the host device and the target device if no competing request to access the target device has been received;

the first computed probability being determined by the connection manager and being proportional to a number of links in the pathway, the first computed probability involving a potential connection collision with another initiator requesting to connect to the target device, the connection manager to allocate the connection to the host device when the first computed probability of the first blocked pathway is higher than a second computed probability of a second blocked pathway between the another initiator and the target device.

8. The method of claim 7 further comprising:

determining whether the competing request has a higher probability of a blocked pathway than the connection between the host device and the target device if a competing request to access the target device has been received; and

terminating the connection between the host device and the target device if the competing request has the higher probability of a blocked pathway.

9. The method of claim 8 further comprising maintaining the open connection between the host device and the target device if the received competing request has a lower probability of a blocked pathway.

10. The method of claim 9 further comprising:

determining whether a timer has expired if the received competing request has the lower probability of a blocked pathway; and

terminating the connection between the host device and the target device if the competing request has the lower probability of a blocked pathway and the timer has expired.

11. The method of claim 7 further comprising terminating the connection if no additional data is to be transferred between the host device and the target device.

12. A system comprising:

a hard disk drive; and

a host device, coupled to the hard disk drive, having a connection manager to determine, based upon a first computed probability of a first blocked pathway, when to allocate a connection with the hard disk drive, the first computed probability being computed after discovery of a target device by a host device, the first computed probability being determined by the connection manager and being proportional to a number of links in the first pathway, the first computed probability involving a potential connection collision with another initiator requesting to connect to the target device, the connection manager to allocate the connection to the host device when the first computed probability is higher than a second computed probability of a second blocked pathway between the another initiator and the target device.

13. The system of claim 12 wherein the connection manager maintains an open connection to the hard disk drive if additional data is to be transmitted to the hard disk drive and there is no competing request to access the hard disk drive.

14. The system of claim 13 wherein the connection manager closes the connection with the hard disk drive upon detecting that there is a competing request to access the hard disk drive and the competing request has a higher probability of a blocked pathway than the connection being serviced.

15. The system of claim 14 wherein the connection manager maintains the open connection to the hard disk drive if there is a competing request to access the hard disk drive and the competing request has a lower probability of a blocked pathway connection being serviced.

16. The system of claim 13 wherein the connection manager comprises a timer to track the time the connection is open with the hard disk drive.

17. A method comprising:

determining, based upon a first computed probability of a first blocked pathway, when to establish a connection between a first host device and a target device via a connection manager at the first host device, the first computed probability being computed after discovery of the target device by the first host device;

transferring input/output (I/O) data between the first host device and the target device;

determining if additional I/O data is to be transferred between the first host device and the target device;

determining if a timer has expired;

determining if a competing request to access the target device has been received if the timer has expired; and

maintaining an open connection between the first host device and the target device to transfer the additional data if no competing request to access the target device has been received, the first computed probability being determined by the connection manager and being proportional to a number of links in the pathway, the first computed probability involving a potential connection collision with a second host device requesting to connect to the target device, the connection manager to allocate the connection to the first host device when the first computed probability is higher than a second computed probability of a second blocked pathway between the second host device and the target device.

18. The method of claim 17 further comprising resetting the timer if no competing request to access the target device has been received.

19. The method of claim 17 further comprising terminating the connection between the first host device and the target device if the timer has expired and a competing request has been received.

20. The method of claim 17 further comprising maintaining the connection between the first host device and the target device if the timer has not expired and a competing request has been received.

21. The method of claim 17 further comprising terminating the connection between the first host device and the target device if no additional I/O data is to be transferred between the first host device and the target device.

22. An article of manufacture including a tangible computer readable medium that stores a program of instructions, wherein the program of instructions, when executed by a processing unit, causes the processing unit to perform the process of:

determining, based upon a first computed probability of a first blocked pathway, when to establish a connection between a host device and a target device via a connection manager at the host device, the first computed probability being computed after discovery of the target device by the host device;

transferring input/output (I/O) data between the host device and the target device;

determining if additional I/O data is to be transferred between the host device and the target device;

determining if a competing request to access the target device has been received if additional I/O data is to be transferred between the host device and the target device; and

maintaining an open connection between the host device and the target device if no competing request to access the target device has been received;

the first computed probability being determined by the connection manager and being proportional to a number of links in the pathway, the first computed probability involving a potential connection collision with another initiator requesting to connect to the target device, the connection manager to allocate the connection to the host device when the first computed probability is higher than a second computed probability of a second blocked pathway between the another initiator and the target device.

23. The article of manufacture of claim 22 wherein the program of instructions, when executed by the processing unit, further causes the processing unit to perform the process of:

determining whether the competing request has a higher probability of a blocked pathway than the connection between the host device and the target device if the competing request to access the target device has been received; and

terminating the connection between the host device and the target device if the competing request has the higher probability of a blocked pathway.

24. The article of manufacture of claim 23 wherein the program of instructions, when executed by the processing unit, further causes the processing unit to perform the process of maintaining the open connection between the host device and the target device if the received competing request has a lower probability of a blocked pathway.

25. The article of manufacture of claim 24 wherein the program of instructions, when executed by a processing unit, further causes the processing unit to perform the process of:

determining whether a timer has expired if the received competing request has a lower probability of a blocked pathway; and

terminating the connection between the host device and the target device if the competing request has the lower probability of a blocked pathway and the timer has expired.

26. The article of manufacture of claim 22 wherein the program of instructions, when executed by the processing unit, further causes the processing unit to perform the process of terminating the connection if no additional I/O data is to be transferred between the host device and the target device.