DPDK PMDs typically poll on rings, making the cores look 100% busy to the OS. Using Power Management Unit (PMU) counters, it is possible to differentiate between busy and non-busy poll loops, allowing scaling down of the core frequency during low-traffic situations, and scaling up (including Turbo) in high traffic situations, without modifying the application. A patch demonstrating this method has been added to DPDK 18.08 using the branch hits and branch misses PMU counters. The talk will give an overview of power management techniques in DPDK, and detail the methods used in the latest DPDK Power Management features.
