摘要 |
I/O adapters, such as InfiniBand(TM) 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. |