cgroups

Documentation

Index

• Constants
• Variables
• func CreatePodCgroup(podID types.PodID, hostname types.NodeName, c Config, s Subsystemer) error
• type CgroupID
  • func CgroupIDForLaunchable(s Subsystemer, podID types.PodID, nodeName types.NodeName, launchableID string) (*CgroupID, error)
  • func CgroupIDForPod(s Subsystemer, podID types.PodID, nodeName types.NodeName) (*CgroupID, error)
  • func (c *CgroupID) String() string
• type Config
• type ProcSubsystemer
  • func (ps *ProcSubsystemer) Find() (Subsystems, error)
• type Subsystemer
• type Subsystems
  • func (subsys Subsystems) AddPID(name string, pid int) error
  • func (subsys Subsystems) SetCPU(name CgroupID, cpus int) error
  • func (subsys Subsystems) SetMemory(name CgroupID, bytes int) error
  • func (subsys Subsystems) Write(config Config) error
• type UnsupportedError
  • func (err UnsupportedError) Error() string

Constants

const (
	CPUPeriod = 1000000 // 1 million microseconds which equals 1 second
)

Variables

var DefaultSubsystemer = &ProcSubsystemer{}

var DefaultSubsystems = Subsystems{
	CPU:    "/cgroup/cpu",
	Memory: "/cgroup/memory",
	Prefix: "/cgroup",
}

Functions

func CreatePodCgroup

func CreatePodCgroup(podID types.PodID, hostname types.NodeName, c Config, s Subsystemer) error

CreatePodCgroup will set cgroup parameters for the specified pod with podID on hostname. In order for nested cgroups to work correctly, the path used here must match the path used in pkg/servicebuilder

Types

type CgroupID

type CgroupID string

func CgroupIDForLaunchable

func CgroupIDForLaunchable(s Subsystemer, podID types.PodID, nodeName types.NodeName, launchableID string) (*CgroupID, error)

CgroupIDForLaunchable encapsulates the cgroup path for launchable cgroups. launchableID is a string because I am too cowardly to break the import cycle caused by importing `launch` here.

func CgroupIDForPod

func CgroupIDForPod(s Subsystemer, podID types.PodID, nodeName types.NodeName) (*CgroupID, error)

CgroupIDForPod encapsulates the cgroup path for pod cgroups. This function should match CgroupIDForLaunchable

func (*CgroupID) String

func (c *CgroupID) String() string

type Config

type Config struct {
	Name   CgroupID       `yaml:"-"`                // The name of the cgroup in cgroupfs
	CPUs   int            `yaml:"cpus,omitempty"`   // The number of logical CPUs
	Memory size.ByteCount `yaml:"memory,omitempty"` // The number of bytes of memory
}

Config combines an ID and subsystem limits

type ProcSubsystemer

type ProcSubsystemer struct {
	CachedSubsystems *Subsystems
}

ProcSubsystemer returns cgroup mountpoints based on the /proc filesystem

func (*ProcSubsystemer) Find

func (ps *ProcSubsystemer) Find() (Subsystems, error)

type Subsystemer

type Subsystemer interface {
	Find() (Subsystems, error)
}

Subsystemer is anything that can find a set of Subsystems

type Subsystems

type Subsystems struct {
	CPU    string
	Memory string
	Prefix string
}

maps cgroup subsystems to their respective paths

func (Subsystems) AddPID

func (subsys Subsystems) AddPID(name string, pid int) error

func (Subsystems) SetCPU

func (subsys Subsystems) SetCPU(name CgroupID, cpus int) error

SetCPU will set a number of CPU limits in the cgroup specified by the argument. A sentinel value of 0 will create an unrestricted CPU subsystem https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt

func (Subsystems) SetMemory

func (subsys Subsystems) SetMemory(name CgroupID, bytes int) error

SetMemory will set several memory limits in the cgroup specified in the argument. A sentinel value of 0 will create an unrestricted memory subsystem https://www.kernel.org/doc/Documentation/cgroups/memory.txt

func (Subsystems) Write

func (subsys Subsystems) Write(config Config) error

type UnsupportedError

type UnsupportedError string

func (UnsupportedError) Error

func (err UnsupportedError) Error() string