Android: 怎樣設置app不被系統k掉

有一種方法可以設置app永遠不會被kill，AndroidManifest.xml 中添加:   android:persistent="true" 適用於放在/system/app下的app   設置後app提升為系統核心級別，任何情況下不會被kill掉, settings->applications裡面也會屏蔽掉stop操作, 設置前 Proc #19: adj=svc  /B 4067b028 255:com.xxx.xxx/10001 (started-services) # cat /proc/255/oom_adj 4 設置後 PERS #19: adj=core /F 406291f0 155:com.xxx.xxx/10001 (fixed) # cat /proc/155/oom_adj -12   lowmemorykiller的操作規則比如為 write /sys/module/lowmemorykiller/parameters/adj 0,1,2,4,7,15 write /sys/module/lowmemorykiller/parameters/minfree 2048,3072,4096,6144,7168,8192   可以看到，設置persistent後， oom_adj=-12，永遠沒有機會被lowmemorykiller處理   android:persistent  Whether or not the application should remain running at all times — "true" if it should, and "false" if not. The default value is "false". Applications should not normally set this flag; persistence mode is intended only for certain system applications   代碼  

ActivityManagerService.java  
    final ProcessRecord addAppLocked(ApplicationInfo info) {  
        ProcessRecord app = getProcessRecordLocked(info.processName, info.uid);  
  
  
        if (app == null) {  
            app = newProcessRecordLocked(null, info, null);  
            mProcessNames.put(info.processName, info.uid, app);  
            updateLruProcessLocked(app, true, true);  
        }  
  
  
        if ((info.flags&(ApplicationInfo.FLAG_SYSTEM|ApplicationInfo.FLAG_PERSISTENT))  
                == (ApplicationInfo.FLAG_SYSTEM|ApplicationInfo.FLAG_PERSISTENT)) {  
            app.persistent = true;  
            app.maxAdj = CORE_SERVER_ADJ;  
        }  
        if (app.thread == null && mPersistentStartingProcesses.indexOf(app) < 0) {  
            mPersistentStartingProcesses.add(app);  
            startProcessLocked(app, "added application", app.processName);  
        }  
  
  
        return app;  
    }  

 

  可以看到同時符合FLAG_SYSTEM(/system/app目錄)及FLAG_PERSISTENT(android:persistent="true") 的app，設置app.maxAdj = CORE_SERVER_ADJ(-12)，而adj=-12不會被lowmemorykiller處理