optimize perfd code

device.go

@@ -647,30 +647,18 @@ func (d *device) PerfStart(opts ...PerfOption) (data <-chan []byte, err error) {
 	if perfOptions.SysCPU || perfOptions.SysMem || perfOptions.SysDisk ||
 		perfOptions.SysNetwork || len(perfOptions.ProcessAttributes) > 1 {
 
-		if perfOptions.SysCPU {
-			memoryAttr := []string{
-				"vmCompressorPageCount",
-				"vmExtPageCount",
-				"vmFreeCount",
-				"vmIntPageCount",
-				"vmPurgeableCount",
-				"vmWireCount",
-				"vmUsedCount",
-				"__vmSwapUsage"}
-			perfOptions.SystemAttributes = append(perfOptions.SystemAttributes, memoryAttr...)
-		}
-
-		if perfOptions.SysMem && !perfOptions.SysCPU {
-			memoryAttr := []string{
-				"vmCompressorPageCount",
-				"vmExtPageCount",
-				"vmFreeCount",
-				"vmIntPageCount",
-				"vmPurgeableCount",
-				"vmWireCount",
-				"vmUsedCount",
-				"__vmSwapUsage"}
-			perfOptions.SystemAttributes = append(perfOptions.SystemAttributes, memoryAttr...)
+		sysCpuAndMemAttr := []string{
+			"vmCompressorPageCount",
+			"vmExtPageCount",
+			"vmFreeCount",
+			"vmIntPageCount",
+			"vmPurgeableCount",
+			"vmWireCount",
+			"vmUsedCount",
+			"__vmSwapUsage"}
+
+		if perfOptions.SysMem || perfOptions.SysCPU {
+			perfOptions.SystemAttributes = append(perfOptions.SystemAttributes, sysCpuAndMemAttr...)
 		}
 
 		if perfOptions.SysDisk {

perfd_test.go

@@ -32,6 +32,76 @@ func TestPerfSystemMonitor(t *testing.T) {
 	}
 }
 
+func TestPerfSystemCpu(t *testing.T) {
+	setupLockdownSrv(t)
+
+	data, err := dev.PerfStart(
+		WithPerfSystemCPU(true),
+		WithPerfOutputInterval(1000),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	timer := time.NewTimer(time.Duration(time.Second * 10))
+	for {
+		select {
+		case <-timer.C:
+			dev.PerfStop()
+			return
+		case d := <-data:
+			fmt.Println(string(d))
+		}
+	}
+}
+
+func TestPerfSystemMem(t *testing.T) {
+	setupLockdownSrv(t)
+
+	data, err := dev.PerfStart(
+		WithPerfSystemMem(true),
+		WithPerfOutputInterval(1000),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	timer := time.NewTimer(time.Duration(time.Second * 10))
+	for {
+		select {
+		case <-timer.C:
+			dev.PerfStop()
+			return
+		case d := <-data:
+			fmt.Println(string(d))
+		}
+	}
+}
+
+func TestPerfNotSystemPerfData(t *testing.T) {
+	setupLockdownSrv(t)
+
+	data, err := dev.PerfStart(
+		WithPerfSystemMem(false),
+		WithPerfSystemCPU(false),
+		WithPerfOutputInterval(1000),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	timer := time.NewTimer(time.Duration(time.Second * 10))
+	for {
+		select {
+		case <-timer.C:
+			dev.PerfStop()
+			return
+		case d := <-data:
+			fmt.Println(string(d))
+		}
+	}
+}
+
 func TestPerfProcessMonitor(t *testing.T) {
 	setupLockdownSrv(t)