cpuidle

Documentation

Overview

Package cpuidle is the C-state writer used by the cpuclass handler. It wraps the goresctrl cstates library, exposing a uniform Hooks-injectable interface that matches the cpufreq and uncorefreq writers.

Index

• type Hooks
• type Writer
  • func NewWriter(hooks Hooks) *Writer
  • func (w *Writer) Enforce(class string, disabledCstates []string, cpus []int) error

Types

type Hooks

type Hooks struct {
	Apply func(cpus []int, enabled, disabled []string) error
}

Hooks lets tests intercept the cstate apply operations without touching real sysfs. Production use leaves all hooks nil; the writer then talks to the platform via goresctrl. The two hooks mirror the two Apply calls performed per enforce(): enable and disable.

type Writer

type Writer struct {
	// contains filtered or unexported fields
}

Writer enforces per-class enable/disable bits across the cstate names exposed by the platform. The cstates handle is created lazily on first enforce() call that has any disabled cstates; hosts and tests that never request a cstate change therefore never touch the cpuidle sysfs.

func NewWriter

func NewWriter(hooks Hooks) *Writer

NewWriter returns a Writer wired to the given hooks. Pass a zero-valued Hooks to use real sysfs via goresctrl.

func (*Writer) Enforce

func (w *Writer) Enforce(class string, disabledCstates []string, cpus []int) error

Enforce applies the class-specific C-state enable/disable mask on the given CPUs. An empty disabledCstates leaves the writer untouched as long as the cstates handle has never been initialized. Returns the first error encountered.