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Power / Energy

Example

General power information:

julia> power = LIKWID.Power.get_power_info()
LIKWID.PowerInfo
├ baseFrequency: 3300.0 MHz
├ minFrequency: 1200.0 MHz
├ turbo: TurboBoost()
├ hasRAPL: true
├ powerUnit: 125000.0
├ timeUnit: 976.0
├ uncoreMinFreq: 1200.0 MHz
├ uncoreMaxFreq: 2400.0 MHz
├ perfBias: 6
└ domains: ... (5 elements)

julia> power.domains
(PowerDomain(PKG, ...), PowerDomain(PP0, ...), PowerDomain(PP1, ...), PowerDomain(DRAM, ...), PowerDomain(PLATFORM, ...))

julia> first(power.domains)
LIKWID.PowerDomain
├ id: 0
├ type: PKG
├ supportFlags: 27
├ energyUnit: 6.103515625e-5
├ tdp: 1.65e8
├ minPower: 6.8e7
├ maxPower: 1.65e8
├ maxTimeWindow: 31232.0
├ supportInfo: true
├ supportStatus: true
├ supportPerf: true
├ supportPolicy: false
└ supportLimit: true

Energy measurement:

julia> LIKWID.Power.measure(; cpuid=0, domainid=0) do
        sleep(1)
       end
29.9920654296875 μJ

julia> LIKWID.Power.measure(; cpuid=0, domainid=0) do
        sum(sin(rand()) for _ in 1:1_000_000)
       end
0.5574951171875 μJ

(Note that the example requires that the first (perhaps only) Julia thread is pinned to the CPU thread with id 0.)

Index

Functions

LIKWID.Power.init — Function

Initialize power measurements for the given CPU. Returns the RAPL status, i.e. false (no RAPL) or true (RAPL working).

source
LIKWID.Power.get_power — Function
get_power(p_start::Integer, p_stop::Integer, domainid::Integer)

Calculate the μJ from the values retrieved by start_power() and stop_power().

source
LIKWID.Power.measure — Function
measure(f; cpuid::Integer=0, domainid::Integer)

Measure / calculate the energy for the given cpuid and domainid over the execution of the function f using Power.start_power, Power.stop_power, etc. under the hood. Automatically initializes and finalizes the power module.

Examples

julia> LIKWID.Power.measure(; cpuid=0, domainid=0) do
           sleep(1)
       end
15.13702392578125 μJ
source

Types