摘要 |
A computer system such as a server pipelines RNIC interface (RI) management/control operations such as memory registration operations to hide from network applications the latency in performing RDMA work requests caused in part by delays in processing the memory registration operations and the time required to execute the registration operations themselves. A separate QP-like structure, called a control QP (CQP), interfaces with a control processor (CP) to form a control path pipeline, separate from the transaction pipeline, which is designated to handle all control path traffic associated with the processing of RI control operations. This includes memory registration operations (MR OPs), as well as the creation and destruction of traditional QPs for processing RDMA transactions. Once the MR OP has been queued in the control path pipeline of the adapter, a pending bit is set which is associated with the MR OP. Processing of an RDMA work request in the transaction pipeline that has engendered the enqueued MR OP is permitted to proceed as if the processing of the MR OP has already been completed. If the work request gets ahead of the MR OP, the associated pending bit being set will notify the adapter's work request transaction pipeline to stall (and possibly reschedule) completion of the work request until the processing of the MR OP for that memory region is complete. When the memory registration process for the memory region is complete, the associated pending bit is reset and the adapter transaction pipeline is permitted to continue processing the work request using the newly registered memory region.
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