tools/power turbostat: Build-in "Low Power Idle" counters support
Linux 4.15 exports the ACPI Low Power Idle Table's
counters in /sys/devices/system/cpu/cpuidle/
low_power_idle_cpu_residency_us
Show this in the "CPU%LPI" column.
Today this reflects the "North Complex"
residency in PC10, so expect it to
closely follow "Pk%pc10".
low_power_idle_system_residency_us
Show this in the "SYS%LPI" column.
Today, this reflects the North is in PC10,
plus the PCH is sufficiently quiescent
to save additional power via the "S0ix"
system state, as measured by the
PCH SLP_S0 counter.