Intel® Arria® 10 Hard Processor System Technical Reference Manual

ID 683711
Date 8/28/2023
Public
Document Table of Contents

8.2.11.2.3. Hurry

Each QoS generator has a hurry level, which can change depending on the bandwidth usage and the QoS generator mode.

Hurry is a mechanism to propagate the master's urgency level to all nodes that receive packets from that master. Hurry allows the master to influence the priority not only of the current transaction, but also of all its transactions that are still active.

When the hurry level is increased at a master, it has the effect of setting the urgency of that master’s transactions to at least the same level as the hurry. As a result, the targets respond to the transactions more quickly.

For example, consider a master whose QoS generator is configured in regulator mode. This QoS generator dynamically raises and lowers its urgency value depending on the traffic it experiences. Packets sent from the master use the QoS generator's current urgency value. If the QoS generator raises its urgency value, it uses the Hurry mechanism to increase the pressure value at every datapath where it has a pending transaction.

The QoS generator implements hurry by broadcasting an urgency packet on every datapath where it has pending transactions. The urgency packet contains the current urgency value, which raises pressure on each datapath.