android app 不会被low memory killer回收

有一种方法可以设置app永远不会被kill，AndroidManifest.xml 中添加: android:persistent="true" 适用于放在/system/app下的app 设置后app提升为系统核心级别，任何情况下不会被kill掉, settings->applications里面也会屏蔽掉stop操作, 设置前 Proc#19:adj=svc/B4067b028255:com.xxx.xxx/10001(started-services) #cat/proc/255/oom_adj 4 设置后 PERS#19:adj=core/F406291f0155:com.xxx.xxx/10001(fixed) #cat/proc/155/oom_adj -12

lowmemorykiller的操作规则比如为

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，设置persistent后， oom_adj=-12，永远没有机会被lowmemorykiller处理

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

代码

[java] view plain copy

ActivityManagerService.java
finalProcessRecordaddAppLocked(ApplicationInfoinfo){
ProcessRecordapp=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,"addedapplication",app.processName);
}
returnapp;
}

可以看到同时符合FLAG_SYSTEM(/system/app目录)及FLAG_PERSISTENT(android:persistent="true")

的app，设置app.maxAdj = CORE_SERVER_ADJ(-12)，而adj=-12不会被lowmemorykiller处理

更多相关文章

随机推荐