From d161bba98c3b841cbb2d98bef357242983908442 Mon Sep 17 00:00:00 2001
From: Sam Yuan <yy19902439@126.com>
Date: Fri, 6 Dec 2024 18:30:03 +0800
Subject: [PATCH] [fix]: try to reduce escapes to heap

Signed-off-by: Sam Yuan <yy19902439@126.com>
---
 pkg/collector/stats/types/types.go             |  4 ++--
 pkg/config/config.go                           |  2 +-
 pkg/kubelet/kubelet_pod_lister.go              |  5 +++--
 pkg/model/types/types.go                       | 10 ++++------
 pkg/sensors/components/source/rapl_msr_util.go |  1 -
 pkg/sensors/components/source/rapl_sysfs.go    | 16 ++++++++++++----
 6 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/pkg/collector/stats/types/types.go b/pkg/collector/stats/types/types.go
index fa0e24cf6f..66a6d6563c 100644
--- a/pkg/collector/stats/types/types.go
+++ b/pkg/collector/stats/types/types.go
@@ -14,10 +14,10 @@ type UInt64Stat struct {
 }
 
 func NewUInt64Stat(aggr, delta uint64) *UInt64Stat {
-	stat := &UInt64Stat{}
+	stat := UInt64Stat{}
 	stat.aggr.Store(aggr)
 	stat.delta.Store(delta)
-	return stat
+	return &stat
 }
 
 func (s *UInt64Stat) String() string {
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 1025916018..c42904ac22 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -234,7 +234,7 @@ func getBoolConfig(configKey string, defaultBool bool) bool {
 }
 
 func getIntConfig(configKey string, defaultInt int) int {
-	defaultValue := fmt.Sprintf("%d", defaultInt)
+	defaultValue := strconv.Itoa(defaultInt)
 	value, err := strconv.Atoi(getConfig(configKey, defaultValue))
 	if err == nil {
 		return value
diff --git a/pkg/kubelet/kubelet_pod_lister.go b/pkg/kubelet/kubelet_pod_lister.go
index 30ff95707e..28a1161dc2 100644
--- a/pkg/kubelet/kubelet_pod_lister.go
+++ b/pkg/kubelet/kubelet_pod_lister.go
@@ -38,6 +38,7 @@ const (
 
 var (
 	podURL string
+	client http.Client
 )
 
 func init() {
@@ -50,6 +51,8 @@ func init() {
 		port = "10250"
 	}
 	podURL = "https://" + nodeName + ":" + port + "/pods"
+	http.DefaultTransport.(*http.Transport).TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
+	client = http.Client{}
 }
 
 func httpGet(url string) (*http.Response, error) {
@@ -65,8 +68,6 @@ func httpGet(url string) (*http.Response, error) {
 		return nil, err
 	}
 	req.Header.Add("Authorization", bearer)
-	http.DefaultTransport.(*http.Transport).TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
-	client := &http.Client{}
 	resp, err := client.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get response from %q: %v", url, err)
diff --git a/pkg/model/types/types.go b/pkg/model/types/types.go
index 51b5a215ee..6f92783be4 100644
--- a/pkg/model/types/types.go
+++ b/pkg/model/types/types.go
@@ -57,18 +57,16 @@ var (
 		LogisticTrainer,
 		ExponentialTrainer,
 	}
+	ModelOutputTypeConverter = []string{"AbsPower", "DynPower"}
+	ModelTypeConverter       = []string{"Ratio", "Regressor", "EstimatorSidecar"}
 )
 
 func getModelOutputTypeConverter() []string {
-	return []string{
-		"AbsPower", "DynPower",
-	}
+	return ModelOutputTypeConverter
 }
 
 func getModelTypeConverter() []string {
-	return []string{
-		"Ratio", "Regressor", "EstimatorSidecar",
-	}
+	return ModelTypeConverter
 }
 
 func (s ModelOutputType) String() string {
diff --git a/pkg/sensors/components/source/rapl_msr_util.go b/pkg/sensors/components/source/rapl_msr_util.go
index e761bb449e..c9c997e74a 100644
--- a/pkg/sensors/components/source/rapl_msr_util.go
+++ b/pkg/sensors/components/source/rapl_msr_util.go
@@ -116,7 +116,6 @@ func ReadMSR(packageID int, msr int64) (uint64, error) {
 	}
 
 	msrVal := byteOrder.Uint64(buf)
-
 	return msrVal, nil
 }
 
diff --git a/pkg/sensors/components/source/rapl_sysfs.go b/pkg/sensors/components/source/rapl_sysfs.go
index e94919dfab..3de1772bf1 100644
--- a/pkg/sensors/components/source/rapl_sysfs.go
+++ b/pkg/sensors/components/source/rapl_sysfs.go
@@ -21,6 +21,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"sync"
 
 	"k8s.io/klog/v2"
 )
@@ -43,7 +44,9 @@ const (
 )
 
 var (
-	eventPaths map[string]map[string]string
+	eventPaths                map[string]map[string]string
+	once                      sync.Once
+	systemCollectionSupported bool
 )
 
 func init() {
@@ -125,9 +128,14 @@ func (PowerSysfs) GetName() string {
 }
 
 func (r *PowerSysfs) IsSystemCollectionSupported() bool {
-	path := fmt.Sprintf(packageNamePathTemplate, 0)
-	_, err := os.ReadFile(path + energyFile)
-	return err == nil
+	// use a hard code to reduce escapes to heap
+	// there are parts of code invokes this function
+	// use once to reduce IO
+	once.Do(func() {
+		_, err := os.ReadFile("/sys/class/powercap/intel-rapl/intel-rapl:0/energy_uj")
+		systemCollectionSupported = (err == nil)
+	})
+	return systemCollectionSupported
 }
 
 func (r *PowerSysfs) GetAbsEnergyFromDram() (uint64, error) {