power

README.md

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+## Power monitoring permissions
+
+In recent kernel versions, precise power monitoring is only accessible to root users to prevent using it as a side-channel attack.
+In order to get the power monitoring output you'll need to give the palantir user access to this data using the following steps.
+
+- Create a group using
+  
+  ```bash
+  sudo groupadd powermonitoring
+  ```
+
+- Create `/etc/udev/rules.d/99-powermonitoring.rules` with
+  ```udev
+  SUBSYSTEM=="powercap", ACTION=="add", RUN+="/bin/chgrp -R powermonitoring /sys%p", RUN+="/bin/chmod -R g=u /sys%p"                                                                                                                                             
+  SUBSYSTEM=="powercap", ACTION=="change", ENV{TRIGGER}!="none", RUN+="/bin/chgrp -R powermonitoring /sys%p", RUN+="/bin/chmod -R g=u /sys%p"
+  ```
+
+- Apply the udev rules
+  
+  ```
+  sudo udevadm control --reload-rules && sudo udevadm trigger
+  ```
+
+- Add your user to the group
+  
+  ```
+  sudo usermod -a G powermonitoring palantir
+  ```
+
+- Verify that you can read energy usage
+
+  ```
+  sudo su - palantir -c 'cat /sys/class/powercap/intel-rapl:0:0/energy_uj
+  ```