Method startWithCPUAffinity

libcontainer/process_linux.go:215–240

Starts setns process with specified initial CPU affinity.

()

// Starts setns process with specified initial CPU affinity.
func (p *setnsProcess) startWithCPUAffinity() error {
	aff := p.config.CPUAffinity
	if aff == nil || aff.Initial == nil {
		return p.cmd.Start()
	}
	errCh := make(chan error)
	defer close(errCh)

	// Use a goroutine to dedicate an OS thread.
	go func() {
		runtime.LockOSThread()
		// Command inherits the CPU affinity.
		if err := unix.SchedSetaffinity(unix.Gettid(), aff.Initial); err != nil {
			errCh <- fmt.Errorf("error setting initial CPU affinity: %w", err)
			return
		}

		errCh <- p.cmd.Start()
		// Deliberately omit runtime.UnlockOSThread here.
		// https://pkg.go.dev/runtime#LockOSThread says:
		// "If the calling goroutine exits without unlocking the
		// thread, the thread will be terminated".
	}()

	return <-errCh
}

func (p *setnsProcess) setFinalCPUAffinity() error {
	aff := p.config.CPUAffinity