dumpsys cpuinfo_permission denial: can't dump cpuinfo from from

文章出处：https://blog.csdn.net/shift_wwx/article/details/42555135

根据android 中的dumpsys和android 查看内存使用情况不做过多的source code解析。

根据：

ServiceManager.addService("cpuinfo", new CpuBinder(m));

找到CpuBinder：

        @Override
        protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
            if (mActivityManagerService.checkCallingPermission(android.Manifest.permission.DUMP)
                    != PackageManager.PERMISSION_GRANTED) {
                pw.println("Permission Denial: can't dump cpuinfo from from pid="
                        + Binder.getCallingPid() + ", uid=" + Binder.getCallingUid()
                        + " without permission " + android.Manifest.permission.DUMP);
                return;
            }
 
            synchronized (mActivityManagerService.mProcessCpuThread) {
                pw.print(mActivityManagerService.mProcessCpuTracker.printCurrentLoad());
                pw.print(mActivityManagerService.mProcessCpuTracker.printCurrentState(
                        SystemClock.uptimeMillis()));
            }
        }

最终就可以获取cpu使用情况了：

130|root@h15:/ # dumpsys cpuinfo
Load: 0.44 / 0.49 / 0.5
CPU usage from 79896ms to 19892ms ago:
  48% 3803/kdvb-ad-0-fe-0: 0% user + 48% kernel
  0.5% 6221/kworker/1:0: 0% user + 0.5% kernel
  0.5% 6336/kworker/0:1: 0% user + 0.5% kernel
  0.2% 2586/tvserver: 0% user + 0.2% kernel
  0.1% 1549/kthread_di: 0% user + 0.1% kernel
  0% 3749/system_server: 0% user + 0% kernel / faults: 1 minor
  0% 2591/surfaceflinger: 0% user + 0% kernel
  0% 3887/com.android.systemui: 0% user + 0% kernel / faults: 4 minor
  0% 4034/com.qiyi.video: 0% user + 0% kernel / faults: 2 minor
25% TOTAL: 0% user + 25% kernel