6.3.2 HN-F counters

Applications can bottleneck on one or more HN-Fs because they frequently target an address or a stream of addresses.

The following POCQ occupancy and request retry events are used to monitor possible performance loss in the system:

PMU_HN_POCQ_RETRY_EVENTThe total number of requests that have been retried.
PMU_HN_POCQ_REQS_RECVD_EVENTThe total number of requests that the HN-F receives.

Requests that cannot be queued in the POCQ, because of lack of credits, are retried. The HN-F responds with a RetryAck response, and the request waits for a static credit. This indicates whether the bottlenecks are caused by a lack of credits, and also shows if the latency of requests is very high.

Calculate the message retry rate as follows:

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