feat: add gomaxprocs limt and return node fit error in advance

cmd/descheduler/descheduler.go

@@ -19,6 +19,7 @@ package main
 import (
 	"os"
 
+	_ "go.uber.org/automaxprocs"
 	"k8s.io/component-base/cli"
 	"sigs.k8s.io/descheduler/cmd/descheduler/app"
 )

go.mod

@@ -12,6 +12,7 @@ require (
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.24.0
 	go.opentelemetry.io/otel/sdk v1.24.0
 	go.opentelemetry.io/otel/trace v1.24.0
+	go.uber.org/automaxprocs v1.5.3
 	google.golang.org/grpc v1.62.0
 	k8s.io/api v0.30.0
 	k8s.io/apimachinery v0.30.0

go.sum

@@ -141,6 +141,8 @@ github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
+github.com/prashantv/gostub v1.1.0/go.mod h1:A5zLQHz7ieHGG7is6LLXLz7I8+3LZzsrV0P1IAHhP5U=
 github.com/prometheus/client_golang v1.16.0 h1:yk/hx9hDbrGHovbci4BY+pRMfSuuat626eFsHb7tmT8=
 github.com/prometheus/client_golang v1.16.0/go.mod h1:Zsulrv/L9oM40tJ7T815tM89lFEugiJ9HzIqaAx4LKc=
 github.com/prometheus/client_model v0.4.0 h1:5lQXD3cAg1OXBf4Wq03gTrXHeaV0TQvGfUooCfx1yqY=
@@ -215,6 +217,8 @@ go.opentelemetry.io/otel/trace v1.24.0 h1:CsKnnL4dUAr/0llH9FKuc698G04IrpWV0MQA/Y
 go.opentelemetry.io/otel/trace v1.24.0/go.mod h1:HPc3Xr/cOApsBI154IU0OI0HJexz+aw5uPdbs3UCjNU=
 go.opentelemetry.io/proto/otlp v1.1.0 h1:2Di21piLrCqJ3U3eXGCTPHE9R8Nh+0uglSnOyxikMeI=
 go.opentelemetry.io/proto/otlp v1.1.0/go.mod h1:GpBHCBWiqvVLDqmHZsoMM3C5ySeKTC7ej/RNTae6MdY=
+go.uber.org/automaxprocs v1.5.3 h1:kWazyxZUrS3Gs4qUpbwo5kEIMGe/DAvi5Z4tl2NW4j8=
+go.uber.org/automaxprocs v1.5.3/go.mod h1:eRbA25aqJrxAbsLO0xy5jVwPt7FQnRgjW+efnwa1WM0=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=

pkg/descheduler/node/node.go

@@ -18,13 +18,13 @@ package node
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
-	utilerrors "k8s.io/apimachinery/pkg/util/errors"
 	clientset "k8s.io/client-go/kubernetes"
 	listersv1 "k8s.io/client-go/listers/core/v1"
 	"k8s.io/klog/v2"
@@ -104,40 +104,42 @@ func IsReady(node *v1.Node) bool {
 // This function is used when the NodeFit pod filtering feature of the Descheduler is enabled.
 // This function currently considers a subset of the Kubernetes Scheduler's predicates when
 // deciding if a pod would fit on a node, but more predicates may be added in the future.
-func NodeFit(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, node *v1.Node) []error {
+func NodeFit(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, node *v1.Node) error {
 	// Check node selector and required affinity
-	var errors []error
 	if ok, err := utils.PodMatchNodeSelector(pod, node); err != nil {
-		errors = append(errors, err)
+		return err
 	} else if !ok {
-		errors = append(errors, fmt.Errorf("pod node selector does not match the node label"))
+		return errors.New("pod node selector does not match the node label")
 	}
+
 	// Check taints (we only care about NoSchedule and NoExecute taints)
 	ok := utils.TolerationsTolerateTaintsWithFilter(pod.Spec.Tolerations, node.Spec.Taints, func(taint *v1.Taint) bool {
 		return taint.Effect == v1.TaintEffectNoSchedule || taint.Effect == v1.TaintEffectNoExecute
 	})
 	if !ok {
-		errors = append(errors, fmt.Errorf("pod does not tolerate taints on the node"))
+		return errors.New("pod does not tolerate taints on the node")
 	}
+
 	// Check if the pod can fit on a node based off it's requests
 	if pod.Spec.NodeName == "" || pod.Spec.NodeName != node.Name {
-		if ok, reqErrors := fitsRequest(nodeIndexer, pod, node); !ok {
-			errors = append(errors, reqErrors...)
+		if ok, reqError := fitsRequest(nodeIndexer, pod, node); !ok {
+			return reqError
 		}
 	}
+
 	// Check if node is schedulable
 	if IsNodeUnschedulable(node) {
-		errors = append(errors, fmt.Errorf("node is not schedulable"))
+		return errors.New("node is not schedulable")
 	}
 
 	// Check if pod matches inter-pod anti-affinity rule of pod on node
 	if match, err := podMatchesInterPodAntiAffinity(nodeIndexer, pod, node); err != nil {
-		errors = append(errors, err)
+		return err
 	} else if match {
-		errors = append(errors, fmt.Errorf("pod matches inter-pod anti-affinity rule of other pod on node"))
+		return errors.New("pod matches inter-pod anti-affinity rule of other pod on node")
 	}
 
-	return errors
+	return nil
 }
 
 // PodFitsAnyOtherNode checks if the given pod will fit any of the given nodes, besides the node
@@ -149,13 +151,14 @@ func PodFitsAnyOtherNode(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.
 			continue
 		}
 
-		errors := NodeFit(nodeIndexer, pod, node)
-		if len(errors) == 0 {
+		err := NodeFit(nodeIndexer, pod, node)
+		if err == nil {
 			klog.V(4).InfoS("Pod fits on node", "pod", klog.KObj(pod), "node", klog.KObj(node))
 			return true
 		}
+
 		klog.V(4).InfoS("Pod does not fit on any other node",
-			"pod:", klog.KObj(pod), "node:", klog.KObj(node), "error:", utilerrors.NewAggregate(errors).Error())
+			"pod", klog.KObj(pod), "node", klog.KObj(node), "error", err.Error())
 	}
 
 	return false
@@ -165,13 +168,14 @@ func PodFitsAnyOtherNode(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.
 // to determine if the pod will fit can be found in the NodeFit function.
 func PodFitsAnyNode(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, nodes []*v1.Node) bool {
 	for _, node := range nodes {
-		errors := NodeFit(nodeIndexer, pod, node)
-		if len(errors) == 0 {
+		err := NodeFit(nodeIndexer, pod, node)
+		if err == nil {
 			klog.V(4).InfoS("Pod fits on node", "pod", klog.KObj(pod), "node", klog.KObj(node))
 			return true
 		}
+
 		klog.V(4).InfoS("Pod does not fit on any node",
-			"pod:", klog.KObj(pod), "node:", klog.KObj(node), "error:", utilerrors.NewAggregate(errors).Error())
+			"pod", klog.KObj(pod), "node", klog.KObj(node), "error", err)
 	}
 
 	return false
@@ -180,14 +184,14 @@ func PodFitsAnyNode(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod,
 // PodFitsCurrentNode checks if the given pod will fit onto the given node. The predicates used
 // to determine if the pod will fit can be found in the NodeFit function.
 func PodFitsCurrentNode(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, node *v1.Node) bool {
-	errors := NodeFit(nodeIndexer, pod, node)
-	if len(errors) == 0 {
+	err := NodeFit(nodeIndexer, pod, node)
+	if err == nil {
 		klog.V(4).InfoS("Pod fits on node", "pod", klog.KObj(pod), "node", klog.KObj(node))
 		return true
 	}
 
 	klog.V(4).InfoS("Pod does not fit on current node",
-		"pod:", klog.KObj(pod), "node:", klog.KObj(node), "error:", utilerrors.NewAggregate(errors).Error())
+		"pod", klog.KObj(pod), "node", klog.KObj(node), "error", err)
 
 	return false
 }
@@ -200,9 +204,7 @@ func IsNodeUnschedulable(node *v1.Node) bool {
 
 // fitsRequest determines if a pod can fit on a node based on its resource requests. It returns true if
 // the pod will fit.
-func fitsRequest(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, node *v1.Node) (bool, []error) {
-	var insufficientResources []error
-
+func fitsRequest(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, node *v1.Node) (bool, error) {
 	// Get pod requests
 	podRequests, _ := utils.PodRequestsAndLimits(pod)
 	resourceNames := make([]v1.ResourceName, 0, len(podRequests))
@@ -212,25 +214,22 @@ func fitsRequest(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, nod
 
 	availableResources, err := nodeAvailableResources(nodeIndexer, node, resourceNames)
 	if err != nil {
-		return false, []error{err}
+		return false, err
 	}
 
-	podFitsOnNode := true
 	for _, resource := range resourceNames {
 		podResourceRequest := podRequests[resource]
 		availableResource, ok := availableResources[resource]
 		if !ok || podResourceRequest.MilliValue() > availableResource.MilliValue() {
-			insufficientResources = append(insufficientResources, fmt.Errorf("insufficient %v", resource))
-			podFitsOnNode = false
+			return false, fmt.Errorf("insufficient %v", resource)
 		}
 	}
 	// check pod num, at least one pod number is avaibalbe
 	if availableResources[v1.ResourcePods].MilliValue() <= 0 {
-		insufficientResources = append(insufficientResources, fmt.Errorf("insufficient %v", v1.ResourcePods))
-		podFitsOnNode = false
+		return false, fmt.Errorf("insufficient %v", v1.ResourcePods)
 	}
 
-	return podFitsOnNode, insufficientResources
+	return true, nil
 }
 
 // nodeAvailableResources returns resources mapped to the quanitity available on the node.

pkg/descheduler/node/node_test.go

@@ -824,9 +824,9 @@ func TestNodeFit(t *testing.T) {
 
 			sharedInformerFactory.Start(ctx.Done())
 			sharedInformerFactory.WaitForCacheSync(ctx.Done())
-			errs := NodeFit(getPodsAssignedToNode, tc.pod, tc.node)
-			if (len(errs) == 0 && tc.err != nil) || (len(errs) > 0 && errs[0].Error() != tc.err.Error()) {
-				t.Errorf("Test %#v failed, got %v, expect %v", tc.description, errs, tc.err)
+			err = NodeFit(getPodsAssignedToNode, tc.pod, tc.node)
+			if (err == nil && tc.err != nil) || (err != nil && err.Error() != tc.err.Error()) {
+				t.Errorf("Test %#v failed, got %v, expect %v", tc.description, err, tc.err)
 			}
 		})
 	}

pkg/utils/qos.go

@@ -20,6 +20,10 @@ func isSupportedQoSComputeResource(name v1.ResourceName) bool {
 // A pod is guaranteed only when requests and limits are specified for all the containers and they are equal.
 // A pod is burstable if limits and requests do not match across all containers.
 func GetPodQOS(pod *v1.Pod) v1.PodQOSClass {
+	if len(pod.Status.QOSClass) != 0 {
+		return pod.Status.QOSClass
+	}
+
 	requests := v1.ResourceList{}
 	limits := v1.ResourceList{}
 	zeroQuantity := resource.MustParse("0")