A tool for measuring C-state latency in Linux
The name Wult comes from "Wake Up Latency Tracer". Wult measures C-state latency by scheduling a delayed interrupt at a known time in the future, so it relies on devices allowing for delayed interrupts. Today wult can use LAPIC as the source of delayed interrupts, as well as I210 PCIe Gigabit Ethernet adapter. However, other devices could be supported as well, for example other Intel Ethernet adapters.