cts-verify中BYOD Managed Provisioning ，涉及到low_memorykiller问题

CTS Verifier 中执行 BYOD Managed Provisioning测试项时

camera support cross profile video capture测试项，返回后之前所有的测试结果消失。

跟踪log发现有low_memorykiller的相关信息：

    
    
    
    

     
     
     
     
 
      I/KERNEL ( 88): [ 276.370260] lowmemorykiller: Killing 'id.cts.verifier' (5440), adj 529, 
     
     
     
     
     
 
      I/KERNEL ( 88): [ 276.370260] to free 50908kB on behalf of 'kswapd0' (88) because 
     
     
     
     
     
 
      I/KERNEL ( 88): [ 276.370260] cache 223476kB is below limit 225000kB for oom_score_adj 529 
     
     
     
     
     
 
      I/KERNEL ( 88): [ 276.370260] Free memory is 41032kB above reserved 
     
     
     
     
     
 
      D/Sensors ( 695): setDelay is 100000000 
     
    
    
    
    

出现这个问题的主要原因是，打开camera的应用后吃的内存太多，内存值达到了low_memorykiller的最低阀值，因此该机制杀掉了正在后台的cts-verify应用。

rootcause是修改了阀值导致。

framework：  /framework/base/services/core/java/com/android/server/am/ProcessList.java

该类中有两个数组：

    
    
    
    

     
     
     
     
 
       // These are the low-end OOM level limits. This is appropriate for an 
     
     
     
     
     
 
       // HVGA or smaller phone with less than 512MB. Values are in KB. 
     
     
     
     
     
 
       private final int[] mOomMinFreeLow = new int[] { 
     
     
     
     
     
 
       12288, 18432, 24576, 
     
     
     
     
     
 
       36864, 43008, 49152 
     
     
     
     
     
 
       }; 
     
     
     
     
     
 
       // These are the high-end OOM level limits. This is appropriate for a 
     
     
     
     
     
 
       // 1280x800 or larger screen with around 1GB RAM. Values are in KB. 
     
     
     
     
     
 
       private final int[] mOomMinFreeHigh = new int[] { 
     
     
     
     
     
 
       73728, 92160, 110592, 
     
     
     
     
     
 
       129024, 147456, 184320 
     
     
     
     
     
 
       }; 
     
    
    
    
    

mOomMinFreeLow，mOomMinFreeHigh 

由于目前我对该机制不是特别了解，需要进一步学习下。google一下发现很多大牛都有相关博客总结，得先去学习下。

涉及到的知识点：low_memorykiller机制