Android 系統性能優化：卡頓、穩定性與續航

中興通訊終端事業部，於1998年開始從事手機產品的研發和生產，持續打造以智能手機為核心的“1+2+N”智慧生態，覆蓋運動健康、影音娛樂、商務出行、家庭教育4大場景。用戶遍佈全球160多個國家和地區，手機活躍用戶超過1億，在Android系統的性能優化方面積累了豐富的經驗。在全球範圍內與3000+渠道合作夥伴開展緊密合作，並與全球50家頂級運營商建立戰略合作關系。 中興手機持續強化“創行力”，即創新力+行動力，不斷推進前沿技術落地商用。近兩年，堅持從手機顯示和影像兩個最重要的方面打造特色。在手機顯示方面，作為屏下攝像手機的先驅，中興手機持續3代產品行業商用領先。在影像方面，Axon率先推出三主攝計算攝影，努比亞創新出35mm影像系統。 在移動互聯產品方面，5G CPE全球市占率第一，擁有個人和家庭數據終端、工業互聯終端、車聯網終端三大產品解決方案。

前言

第一部分 卡頓優化

第1章　應用優化案例 ·······················3

1.1　卡頓基本概念 ······························3

1.1.1　卡頓的定義與分類 ···············3

1.1.2 卡頓原因匯總 ·····················6

1.2 卡頓優化涉及的相關技術 ············14

1.2.1 CPU ·······························14

1.2.2 SoC平臺 ·························17

1.2.3 CGroup ···························19

1.2.4 cpuset配置 ······················21

1.2.5 UFS與eMMC ··················23

1.2.6 LCD與屏幕刷新率·············24

1.3 應用耗時操作案例 ······················29

1.3.1 案例1：平臺能力有限與

布□過於復雜 ···················29

1.3.2 案例2：關鍵路徑頻繁I/O

操作 ······························31

1.3.3 案例3：核心函數費時操作···35

1.3.4 案例4：關鍵路徑頻繁數據庫

操作 ······························35

1.3.5 案例5：Binder風暴 ···········38

1.3.6 案例6：UI線程非繪制任務阻

塞繪制 ····························43

1.3.7 案例7：非UI線程上繪制操作

引發阻塞 ·························44

1.4 應用內存案例 ····························46

1.4.1 案例1：聯系人應用內存

泄漏 ······························47

1.4.2 案例2：SystemUI進程Binder

內存泄漏 ·························48

1.4.3 案例3：system內存告警

問題 ······························51

1.4.4 案例4：應用句柄泄漏 ········56

1.4.5 案例5：adj優先級不當引發後

臺應用無法被及時回收 ········59

第2章　系統優化策略與案例分析 ···63

2.1 系統優化策略 ····························63

2.1.1 自啟動管控策略 ················63

2.1.2 消息推送策略 ···················64

2.1.3 關聯啟動管控策略 ·············65

2.1.4 系統側進程啟動管控策略 ·····66

2.1.5 內存融合技術 ···················68

2.1.6 低內存查殺 ······················72

2.2 系統側卡頓優化案例 ··················74

2.2.1 自啟動控制案例 ················74

2.2.2 關聯啟動控制案例 ·············76

2.2.3 線程調度優化案例 ·············80

2.2.4 應用啟動卡頓案例 ·············81

2.2.5 VSync不均勻案例 ·············86

2.2.6 CPU調頻優化案例 ·············89

2.2.7 I/O卡頓案例 ····················92

第二部分 穩定性優化

第3章　 死機重啟問題優化策略與

案例分析 ····························97

3.1 死機重啟問題相關概念 ···············97

3.1.1 死機重啟問題的定義 ··········97

3.1.2 死機問題跟蹤與定位 ··········98

3.1.3 重啟問題跟蹤與定位 ·········101

3.2 死機問題案例分析 ·····················104

3.2.1 DDR位翻轉案例 ··············105

3.2.2 DDR上電時序不穩定案例 ···109

3.2.3 eMMC長時間無響應導致

凍屏死機案例 ··················111

3.2.4 系統運行內存耗盡案例 ·······114

3.2.5 內存踩踏案例 ··················118

3.2.6 硬件中斷風暴踩內存案例 ····123

3.2.7 其他案例 ························127

3.3 重啟問題案例分析 ·····················128

3.3.1 SurfaceFlinger內存高占

案例 ·····························128

3.3.2 system_server 句柄耗盡

案例 ·····························131

3.3.3 PID重復使用案例 ·············132

3.3.4 預置應用共享系統進程UID

案例 ·····························134

3.3.5 system_server線程泄漏

案例 ·····························137

3.3.6 內核代碼浮點運算內存踩踏

案例 ·····························139

第4章　 黑屏問題優化策略與案例

分析 ··································143

4.1 黑屏問題定義和可能的原因 ·······143

4.2 黑屏案例 ··································144

4.2.1 開機流程異常案例 ············144

4.2.2 界面切換黑屏案例 ············147

4.2.3 □□卡頓黑屏案例 ············150

4.2.4 應用邏輯異常導致黑屏

案例 ·····························152

4.2.5 鎖屏黑屏案例 ··················153

第三部分 續航優化

第5章　 外設功耗優化策略與案例

分析 ··································157

5.1 功耗基礎 ··································157

5.1.1 基礎電流分類 ··················158

5.1.2 系統軟件與功耗的關系 ·······158

5.1.3 國家3C發熱標準解讀 ·······160

5.2 外設功耗問題優化策略 ··············161

5.3 外設功耗優化案例 ·····················162

5.3.1 底電流優化案例 ···············162

5.3.2 LCD電流優化案例············167

5.3.3 TP引腳配置優化案例 ········172

5.3.4 音頻參數優化案例 ············172

5.3.5 海運模式電流優化案例 ·······174

第6章　系統優化策略與案例分析 ····176

6.1 續航問題的定義與分類 ··············176

6.2 續航優化涉及的相關技術 ···········177

6.2.1 CPU調度機制 ·················178

6.2.2 Alarm和JobScheduler

機制 ······························181

6.2.3 Doze模式 ·······················183

6.2.4 App Standby機制 ·············186

6.2.5 Bucket機制 ····················188

6.3 系統級優化方案 ························189

6.3.1 溫控方案優化案例 ············190

6.3.2 媒體掃描優化案例 ············197

6.3.3 GMS應用功耗優化案例 ·····200

6.3.4 5G網絡參數優化案例 ········201

6.4 應用異常優化案例 ·····················204

6.4.1 後臺應用CPU高占優化

案例 ·····························204

6.4.2 後臺應用頻繁喚醒優化

案例 ·····························207

6.4.3 後臺應用頻繁聯網優化

案例 ·····························209

6.4.4 後臺應用藍牙掃描優化

案例 ·····························212

6.4.5 後臺應用頻繁定位優化

案例 ·····························214

6.4.6 應用異常持有亮屏鎖優化

案例 ·····························219

後 記 ············································220