}

// Preemptable returns true if preemptor pod can preempt preemptee pod
// if preemptee is not critical or if preemptor's priority is greater than preemptee's priority
func Preemptable(preemptor, preemptee *v1.Pod) bool {
	if IsCriticalPod(preemptor) && !IsCriticalPod(preemptee) {
		return true
	}
	if (preemptor != nil && preemptor.Spec.Priority != nil) &&
		(preemptee != nil && preemptee.Spec.Priority != nil) {

	tests := []struct {
		name      string
		preemptor *v1.Pod
		preemptee *v1.Pod
		expected  bool
	}{
		{
			name:      "a critical preemptor pod preempts a non critical pod",
			preemptor: getTestPod(configSourceAnnotation(FileSource), nil, ""),
			preemptee: getTestPod(nil, nil, ""),
			expected:  true,
		},
		{
			name:      "a preemptor pod with higher priority preempts a critical pod",

			if preemptMSupported && debug.asyncpreemptoff == 0 && needAsync {
				// Rate limit preemptM calls. This is
				// particularly important on Windows
				// where preemptM is actually
				// synchronous and the spin loop here
				// can lead to live-lock.
				now := nanotime()
				if now >= nextPreemptM {
					nextPreemptM = now + yieldDelay/2
					preemptM(asyncM)
				}
			}
		}

		}

		fh.EventRecorder().Eventf(victim, pod, v1.EventTypeNormal, "Preempted", "Preempting", "Preempted by pod %v on node %v", pod.UID, c.Name())
	}

	fh.Parallelizer().Until(ctx, len(c.Victims().Pods), preemptPod, ev.PluginName)
	if err := errCh.ReceiveError(); err != nil {
		return framework.AsStatus(err)
	}

	return s + "]"
}

// sortPodsByQOS returns lists containing besteffort, burstable, and guaranteed pods that
// can be preempted by preemptor pod.
func sortPodsByQOS(preemptor *v1.Pod, pods []*v1.Pod) (bestEffort, burstable, guaranteed []*v1.Pod) {
	for _, pod := range pods {
		if kubetypes.Preemptable(preemptor, pod) {
			switch v1qos.GetPodQOS(pod) {
			case v1.PodQOSBestEffort:
				bestEffort = append(bestEffort, pod)

	debug.SetGCPercent(-1)
	// Out of an abundance of caution, also make sure that there are
	// no GCs actively in progress. The sweep phase of a GC cycle
	// for instance tries to preempt Ps at the very beginning.
	runtime.GC()

	// Start a goroutine with no sync safe-points.
	var ready, ready2 uint32
	go func() {
		for {
			atomic.StoreUint32(&ready, 1)
			dummy()
			dummy()
		}
	}()

	runs := []testRun{
		{
			testName:              "critical pods cannot be preempted",
			inputPods:             []*v1.Pod{allPods[clusterCritical]},
			insufficientResources: getAdmissionRequirementList(0, 0, 1),
			expectErr:             true,
			expectedOutput:        nil,
		},
		{
			testName:              "best effort pods are not preempted when attempting to free resources",

	// If runtime triggers a forced GC during this test then it will deadlock,
	// since the goroutines can't be stopped/preempted.
	// Disable GC for this test (see issue #10958).
	defer debug.SetGCPercent(debug.SetGCPercent(-1))
	// SetGCPercent waits until the mark phase is over, but the runtime
	// also preempts at the start of the sweep phase, so make sure that's
	// done too. See #45867.
	runtime.GC()
	for try := 0; try < N; try++ {

		unlock(&mp.threadLock)
		atomic.Store(&mp.preemptExtLock, 0)
		mp.preemptGen.Add(1)
		return
	}
	var thread uintptr
	if stdcall7(_DuplicateHandle, currentProcess, mp.thread, currentProcess, uintptr(unsafe.Pointer(&thread)), 0, 0, _DUPLICATE_SAME_ACCESS) == 0 {
		print("runtime.preemptM: duplicatehandle failed; errno=", getlasterror(), "\n")
		throw("runtime.preemptM: duplicatehandle failed")
	}
	unlock(&mp.threadLock)

// There're several reasons:
//  1. The pod has a preemptionPolicy of Never.
//  2. The pod has already preempted other pods and the victims are in their graceful termination period.
//     Currently we check the node that is nominated for this pod, and as long as there are
//     terminating pods on this node, we don't attempt to preempt more pods.