Pod comparer should count pods in scheduling queue

Pods in scheduler cache contains both the scheduled pods and those not
scheduled yet in scheduling queue. This commit adds the second group of
pods into consideration while comparing the cache.

pkg/scheduler/core/scheduling_queue.go

@@ -39,8 +39,9 @@ import (
 	priorityutil "k8s.io/kubernetes/pkg/scheduler/algorithm/priorities/util"
 	"k8s.io/kubernetes/pkg/scheduler/util"
 
-	"github.com/golang/glog"
 	"reflect"
+
+	"github.com/golang/glog"
 )
 
 // SchedulingQueue is an interface for a queue to store pods waiting to be scheduled.
@@ -57,6 +58,7 @@ type SchedulingQueue interface {
 	AssignedPodAdded(pod *v1.Pod)
 	AssignedPodUpdated(pod *v1.Pod)
 	WaitingPodsForNode(nodeName string) []*v1.Pod
+	WaitingPods() []*v1.Pod
 }
 
 // NewSchedulingQueue initializes a new scheduling queue. If pod priority is
@@ -116,6 +118,15 @@ func (f *FIFO) Pop() (*v1.Pod, error) {
 	return result.(*v1.Pod), nil
 }
 
+// WaitingPods returns all the waiting pods in the queue.
+func (f *FIFO) WaitingPods() []*v1.Pod {
+	result := []*v1.Pod{}
+	for _, pod := range f.FIFO.List() {
+		result = append(result, pod.(*v1.Pod))
+	}
+	return result
+}
+
 // FIFO does not need to react to events, as all pods are always in the active
 // scheduling queue anyway.
 
@@ -460,6 +471,21 @@ func (p *PriorityQueue) WaitingPodsForNode(nodeName string) []*v1.Pod {
 	return nil
 }
 
+// WaitingPods returns all the waiting pods in the queue.
+func (p *PriorityQueue) WaitingPods() []*v1.Pod {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	result := []*v1.Pod{}
+	for _, pod := range p.activeQ.List() {
+		result = append(result, pod.(*v1.Pod))
+	}
+	for _, pod := range p.unschedulableQ.pods {
+		result = append(result, pod)
+	}
+	return result
+}
+
 // UnschedulablePodsMap holds pods that cannot be scheduled. This data structure
 // is used to implement unschedulableQ.
 type UnschedulablePodsMap struct {