[RK3399][Android7.1] 调试笔记 --- add_tid_to_cgroup failed to write 'xxx' (Permission denied)

Platform: RK3399
OS: Android 7.1
Kernel: v4.4.83

现象：
使用系统的app如音乐，点击的时候有如下error:

01-01 08:12:10.696   779   802 I ActivityManager: Start proc 2696:com.android.musicfx/u0a9 for broadcast com.android.musicfx/.ControlPanelReceiver
01-01 08:12:10.722   779  1382 W SchedPolicy: add_tid_to_cgroup failed to write '2696' (Permission denied); fd=26
01-01 08:12:10.723   779  1382 W ActivityManager: Failed setting process group of 2696 to 0
01-01 08:12:10.723   779  1382 W System.err: java.lang.IllegalArgumentException: Invalid argument: 2696
01-01 08:12:10.723   779  1382 W System.err: 	at android.os.Process.setProcessGroup(Native Method)
01-01 08:12:10.723   779  1382 W System.err: 	at com.android.server.am.ActivityManagerService.applyOomAdjLocked(ActivityManagerService.java:20703)
01-01 08:12:10.723   779  1382 W System.err: 	at com.android.server.am.ActivityManagerService.updateOomAdjLocked(ActivityManagerService.java:21283)
01-01 08:12:10.723   779  1382 W System.err: 	at com.android.server.am.BroadcastQueue.processCurBroadcastLocked(BroadcastQueue.java:274)
01-01 08:12:10.723   779  1382 W System.err: 	at com.android.server.am.BroadcastQueue.sendPendingBroadcastsLocked(BroadcastQueue.java:315)
01-01 08:12:10.723   779  1382 W System.err: 	at com.android.server.am.ActivityManagerService.sendPendingBroadcastsLocked(ActivityManagerServic