support preemption when the number of pods of a node reaches the uppe…

…r limit

Signed-off-by: lili <[email protected]>

pkg/scheduler/api/pod_info.go

@@ -65,6 +65,7 @@ func GetPodResourceRequest(pod *v1.Pod) *Resource {
 	for _, container := range pod.Spec.InitContainers {
 		result.SetMaxResource(NewResource(container.Resources.Requests))
 	}
+	result.AddScalar(v1.ResourcePods, 1)
 
 	return result
 }

pkg/scheduler/api/resource_info.go

@@ -77,6 +77,7 @@ func NewResource(rl v1.ResourceList) *Resource {
 			r.Memory += float64(rQuant.Value())
 		case v1.ResourcePods:
 			r.MaxTaskNum += int(rQuant.Value())
+			r.AddScalar(rName, float64(rQuant.Value()))
 		case v1.ResourceEphemeralStorage:
 			r.AddScalar(rName, float64(rQuant.MilliValue()))
 		default:

pkg/scheduler/plugins/predicates/predicates.go

@@ -415,18 +415,22 @@ func (pp *predicatesPlugin) OnSessionOpen(ssn *framework.Session) {
 		}
 
 		if node.Allocatable.MaxTaskNum <= len(nodeInfo.Pods) {
-			klog.V(4).Infof("NodePodNumber predicates Task <%s/%s> on Node <%s> failed",
-				task.Namespace, task.Name, node.Name)
+			klog.V(4).Infof("NodePodNumber predicates Task <%s/%s> on Node <%s> failed, %d, %d",
+				task.Namespace, task.Name, node.Name, node.Allocatable.MaxTaskNum, len(nodeInfo.Pods))
 			podsNumStatus := &api.Status{
-				// TODO(wangyang0616): When the number of pods of a node reaches the upper limit, preemption is not supported for now.
-				// Record details in #3079 (volcano.sh/volcano)
-				// In the preempt stage, the pipeline of the pod number is not considered,
-				// the preemption of the pod number is released directly, which will cause the pods in the node to be cyclically evicted.
-				Code:   api.UnschedulableAndUnresolvable,
+				Code:   api.Unschedulable,
 				Reason: api.NodePodNumberExceeded,
 			}
 			predicateStatus = append(predicateStatus, podsNumStatus)
-			return predicateStatus, fmt.Errorf("%s", api.NodePodNumberExceeded)
+		}
+		return predicateStatus, nil
+	})
+
+	ssn.AddPredicateFn(pp.Name(), func(task *api.TaskInfo, node *api.NodeInfo) ([]*api.Status, error) {
+		predicateStatus := make([]*api.Status, 0)
+		nodeInfo, found := nodeMap[node.Name]
+		if !found {
+			return predicateStatus, fmt.Errorf("failed to predicates, node info for %s not found", node.Name)
 		}
 
 		predicateByStablefilter := func(pod *v1.Pod, nodeInfo *k8sframework.NodeInfo) ([]*api.Status, bool, error) {