scheduler: Fix memory leak in scheduler cache

The `removeSlice` function was leaving behind references to the
removed element, preventing it from being garbage-collected.
This commit ensures that removed entries are fully cleared,
eliminating the memory leak.

Co-authored-by: ravisastryk <ravisastryk@gmail.com>
Signed-off-by: Sujal Shah <sujalshah28092004@gmail.com>

pkg/scheduler/framework/plugins/defaultpreemption/default_preemption.go

@@ -235,9 +235,11 @@ func (pl *DefaultPreemption) SelectVictimsOnNode(
 	for _, pi := range nodeInfo.GetPods() {
 		if pl.isPreemptionAllowed(nodeInfo, pi, pod) {
 			potentialVictims = append(potentialVictims, pi)
-			if err := removePod(pi); err != nil {
-				return nil, 0, fwk.AsStatus(err)
-			}
+		}
+	}
+	for _, pi := range potentialVictims {
+		if err := removePod(pi); err != nil {
+			return nil, 0, fwk.AsStatus(err)
 		}
 	}
 

pkg/scheduler/framework/types.go

@@ -386,6 +386,8 @@ func removeFromSlice(logger klog.Logger, s []fwk.PodInfo, k string) ([]fwk.PodIn
 			removedPod = s[i]
 			// delete the element
 			s[i] = s[len(s)-1]
+			// clear the reference to prevent potential memory leak
+			s[len(s)-1] = nil
 			s = s[:len(s)-1]
 			break
 		}