sched: provide an option for plugin developers to move pods to activeQ

pkg/scheduler/internal/queue/scheduling_queue.go

@@ -77,6 +77,10 @@ type PreEnqueueCheck func(pod *v1.Pod) bool
 type SchedulingQueue interface {
 	framework.PodNominator
 	Add(pod *v1.Pod) error
+	// Activate moves the given pods to activeQ iff they're in unschedulableQ or backoffQ.
+	// The passed-in pods are originally compiled from plugins that want to activate Pods,
+	// by injecting the pods through a reserved CycleState struct (PodsToActivate).
+	Activate(pods map[string]*v1.Pod)
 	// AddUnschedulableIfNotPresent adds an unschedulable pod back to scheduling queue.
 	// The podSchedulingCycle represents the current scheduling cycle number which can be
 	// returned by calling SchedulingCycle().
@@ -301,6 +305,58 @@ func (p *PriorityQueue) Add(pod *v1.Pod) error {
 	return nil
 }
 
+// Activate moves the given pods to activeQ iff they're in unschedulableQ or backoffQ.
+func (p *PriorityQueue) Activate(pods map[string]*v1.Pod) {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	activated := false
+	for _, pod := range pods {
+		if p.activate(pod) {
+			activated = true
+		}
+	}
+
+	if activated {
+		p.cond.Broadcast()
+	}
+}
+
+func (p *PriorityQueue) activate(pod *v1.Pod) bool {
+	// Verify if the pod is present in activeQ.
+	if _, exists, _ := p.activeQ.Get(newQueuedPodInfoForLookup(pod)); exists {
+		// No need to activate if it's already present in activeQ.
+		return false
+	}
+	var pInfo *framework.QueuedPodInfo
+	// Verify if the pod is present in unschedulableQ or backoffQ.
+	if pInfo = p.unschedulableQ.get(pod); pInfo == nil {
+		// If the pod doesn't belong to unschedulableQ or backoffQ, don't activate it.
+		if obj, exists, _ := p.podBackoffQ.Get(newQueuedPodInfoForLookup(pod)); !exists {
+			klog.ErrorS(nil, "To-activate pod does not exist in unschedulableQ or backoffQ", "pod", klog.KObj(pod))
+			return false
+		} else {
+			pInfo = obj.(*framework.QueuedPodInfo)
+		}
+	}
+
+	if pInfo == nil {
+		// Redundant safe check. We shouldn't reach here.
+		klog.ErrorS(nil, "Internal error: cannot obtain pInfo")
+		return false
+	}
+
+	if err := p.activeQ.Add(pInfo); err != nil {
+		klog.ErrorS(err, "Error adding pod to the scheduling queue", "pod", klog.KObj(pod))
+		return false
+	}
+	p.unschedulableQ.delete(pod)
+	p.podBackoffQ.Delete(pInfo)
+	metrics.SchedulerQueueIncomingPods.WithLabelValues("active", ForceActivate).Inc()
+	p.PodNominator.AddNominatedPod(pInfo.PodInfo, "")
+	return true
+}
+
 // isPodBackingoff returns true if a pod is still waiting for its backoff timer.
 // If this returns true, the pod should not be re-tried.
 func (p *PriorityQueue) isPodBackingoff(podInfo *framework.QueuedPodInfo) bool {