diff --git a/internal/ttlcache/cache_test.go b/internal/ttlcache/cache_test.go
index 9e5c1dc..df01e24 100644
--- a/internal/ttlcache/cache_test.go
+++ b/internal/ttlcache/cache_test.go
@@ -1,6 +1,7 @@
 package ttlcache
 
 import (
+	"github.com/TeaOSLab/EdgeNode/internal/utils/testutils"
 	"github.com/iwind/TeaGo/rands"
 	"runtime"
 	"strconv"
@@ -29,19 +30,26 @@ func TestNewCache(t *testing.T) {
 }
 
 func TestCache_Memory(t *testing.T) {
-	var stat1 = &runtime.MemStats{}
-	runtime.ReadMemStats(stat1)
+	testutils.StartMemoryStats(t)
 
-	cache := NewCache()
-	for i := 0; i < 10_000_000; i++ {
+	var cache = NewCache()
+	var count = 2_000_000
+	for i := 0; i < count; i++ {
 		cache.Write("a"+strconv.Itoa(i), 1, time.Now().Unix()+3600)
 	}
-	t.Log("waiting ...")
 
-	var stat2 = &runtime.MemStats{}
-	runtime.ReadMemStats(stat2)
+	t.Log(cache.Count())
 
-	t.Log((stat2.HeapInuse-stat1.HeapInuse)/1024/1024, "MB")
+	time.Sleep(1 * time.Second)
+	for i := 0; i < count; i++ {
+		if i%2 == 0 {
+			cache.Delete("a" + strconv.Itoa(i))
+		}
+	}
+
+	t.Log(cache.Count())
+
+	cache.Count()
 }
 
 func BenchmarkCache_Add(b *testing.B) {
diff --git a/internal/ttlcache/piece.go b/internal/ttlcache/piece.go
index 6370c9f..1871adb 100644
--- a/internal/ttlcache/piece.go
+++ b/internal/ttlcache/piece.go
@@ -10,7 +10,8 @@ import (
 type Piece struct {
 	m        map[uint64]*Item
 	maxItems int
-	locker   sync.RWMutex
+
+	locker sync.RWMutex
 }
 
 func NewPiece(maxItems int) *Piece {
diff --git a/internal/utils/testutils/memory.go b/internal/utils/testutils/memory.go
new file mode 100644
index 0000000..da864fa
--- /dev/null
+++ b/internal/utils/testutils/memory.go
@@ -0,0 +1,33 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package testutils
+
+import (
+	"fmt"
+	timeutil "github.com/iwind/TeaGo/utils/time"
+	"runtime"
+	"testing"
+	"time"
+)
+
+func StartMemoryStats(t *testing.T) {
+	var ticker = time.NewTicker(1 * time.Second)
+	go func() {
+		var stat = &runtime.MemStats{}
+		var lastHeapInUse uint64
+
+		for range ticker.C {
+			runtime.ReadMemStats(stat)
+			if stat.HeapInuse == lastHeapInUse {
+				return
+			}
+			lastHeapInUse = stat.HeapInuse
+
+			var before = time.Now()
+			runtime.GC()
+			var cost = time.Since(before).Seconds()
+
+			t.Log(timeutil.Format("H:i:s"), "HeapInuse:", fmt.Sprintf("%.2fM", float64(stat.HeapInuse)/1024/1024), "NumGC:", stat.NumGC, "Cost:", fmt.Sprintf("%.4f", cost*1000), "ms")
+		}
+	}()
+}