diff --git a/pkg/scheduler/backend/cache/cache.go b/pkg/scheduler/backend/cache/cache.go
index 48303cce0ce..63d4b57a007 100644
--- a/pkg/scheduler/backend/cache/cache.go
+++ b/pkg/scheduler/backend/cache/cache.go
@@ -697,8 +697,8 @@ func (cache *cacheImpl) run() {
 
 // updateMetrics updates cache size metric values for pods, assumed pods, and nodes
 func (cache *cacheImpl) updateMetrics() {
-	cache.mu.Lock()
-	defer cache.mu.Unlock()
+	cache.mu.RLock()
+	defer cache.mu.RUnlock()
 
 	metrics.CacheSize.WithLabelValues("assumed_pods").Set(float64(len(cache.assumedPods)))
 	metrics.CacheSize.WithLabelValues("pods").Set(float64(len(cache.podStates)))
diff --git a/pkg/scheduler/backend/cache/interface.go b/pkg/scheduler/backend/cache/interface.go
index 72404ff4600..ad3d7d94d4c 100644
--- a/pkg/scheduler/backend/cache/interface.go
+++ b/pkg/scheduler/backend/cache/interface.go
@@ -47,13 +47,11 @@ import (
 //	+--------------------+                     Deleted
 //	      Forget
 //
-//
 // Note that "Initial" and "Deleted" pods do not actually exist in cache.
 // Based on existing use cases, we are making the following assumptions:
 //   - No pod would be assumed twice
 //   - A pod could be added without going through scheduler. In this case, we will see Add but not Assume event.
 //   - If a pod wasn't added, it wouldn't be removed or updated.
-
 type Cache interface {
 	// NodeCount returns the number of nodes in the cache.
 	// DO NOT use outside of tests.