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This revision made February 05, 2012 10:21, by mikeb2701
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To make the PCM counters work on Linux the user running the code needs to read/write access to the /dev/cpu/*/msr files. A nice way to do this is using unix groups.

First create a new group to give msr privileges too:

sudo groupadd msr

Add the user that needs to run the PCM code to that group:

sudo usermod -C msr someuser

Set the permissions on the msr device files to allow that users to read and write (you may need to put this in a script to run at start up if it needs to be persistent).

sudo chgrp msr /dev/cpu/*/msr

Please Confirm