Methods, systems, and storage mediums for timing work requests and completion processing

• US 20060184949A1
• Filed: 02/15/2005
• Published: 08/17/2006
• Est. Priority Date: 02/15/2005
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schmidt, Donald W., Rooney, William J., Craddock, David F.
• Application Number:
  US11/057,943
• Publication Number:
  US 20060184949A1
• Time in Patent Office: Days
• US Class Current: 719/314
• CPC Class Codes: G06F 11/3419 by assessing time
• CPC Class Codes: G06F 11/349 for interfaces, buses
• CPC Class Codes: G06F 2201/805 Real-time
• CPC Class Codes: G06F 2201/87 Monitoring of transactions
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues

Abstract

I/O adapters, such as InfiniBand™ host channel adapters (HCAs) or iWarp remote network interface cards (RNICs) use work requests to pass information to a queue pair and work completions to determine when a work request has completed. Timing information in various stages of processing of these work requests allow a workload manager to identify sources of delay that impacts transaction processing. Work requests request processing that can be marked with a timestamp. Processing stages include: (1) the time when the work request is posted to the send queue, (2) the time when the first packet is sent on the link for that work request, (3) the time at which the work request has completed its processing, and (4) the time when the work completion is retrieved by the software. By comparing the timestamps, the workload manager determines the processing and transaction times.

Claims

1. A method for timing work requests and completion processing, comprising:

storing, by a software driver, a time t1 when a work request is posted to a send queue;

posting, by a hardware adapter, a work completion corresponding to the work request to a completion queue, the work completion including a time t2 when the message for the work request is sent on the link and a time t3 when the work completion is posted to the completion queue;

retrieving, by the software driver, the work completion corresponding to the work request; and

storing, by the software driver, a time t4 when the work completion is retrieved from the completion queue.

2. The method of claim 1, further comprising:

determining a time taken by the hardware adapter to start processing the work request after the work request has been posted from time t1 and time t2.

3. The method of claim 1, further comprising:

determining a time taken to send the message from time t2 and time t3.

4. The method of claim 1, further comprising:

determining a time taken by the software driver to retrieve the work completion from the completion queue from time t4 and time t3.

5. The method of claim 1, wherein timing is only performed by the software driver and the hardware adapter when an indicator in the work request has a predetermined value.

6. The method of claim 1, further comprising:

managing workload by shifting work based on times t1, t2, t3, and t4.

7. The method of claim 1, wherein the time t2 when the message for the work request is sent on the link includes the time for receiving an acknowledgement from a remote node.

8. A system for timing work requests and completion processing, comprising:

a hardware adapter for sending packets on a link;

a software driver for controlling the hardware adapter;

a send queue for holding work requests; and

a completion queue for holding work completions;

wherein the software driver provides a time t1 when a work request is posted to the send queue, the hardware adapter provides a time t2 when a message for the work request is sent on the link, the hardware adapter provides a time t3 when a work completion corresponding to the work request is posted to the completion queue, and the software driver provides a time t4 when the work completion is retrieved from the completion queue.

9. The system of claim 8, wherein a time taken by the hardware adapter to start processing the work request after the work request has been posted is determined from time t1 and time t2.

10. The system of claim 8, wherein a time taken to send the message is determined from time t2 and time t3.

11. The system of claim 8, wherein a time taken by the software driver to retrieve the work completion from the completion queue is determined from time t4 and time t3.

12. The system of claim 8, wherein the software driver has a first timer and the hardware adapter has a second timer and the software driver correlates times from the second timer to times from the first timer.

13. The system of claim 8, wherein timing is only performed by the software driver and the hardware adapter when an indicator in the work request has a predetermined value.

14. The system of claim 8, further comprising:

a workload manager that shifts work based on times t1, t2, t3, and t4.

15. A storage medium for storing instructions for performing a method timing work requests and completion processing, the method comprising:

storing, by a software driver, a time t1 when a work request is posted to a send queue;

posting, by a hardware adapter, a work completion corresponding to the work request to a completion queue, the work completion including a time t2 when the message for the work request is sent on the link and a time t3 when the work completion is posted to the completion queue;

retrieving, by the software driver, the work completion corresponding to the work request; and

storing, by the software driver, a time t4 when the work completion is retrieved from the completion queue.