Many people have posted on odroid forum and elsewhere on how to enable "perf" on XU3 and XU4 boards. After months of trials, one final solution was presented in http://forum.odroid.com/viewtopic.php?f=95&t=6165&p=168238&hilit=perf+xu4#p168238
However, this solution clearly states that the "perf" functionality can be enabled for either the A7 cores or A15 cores but not both at the same time. In my research project, I need to have "perf" enabled across all cores all at the same time. I wonder if a couple of year later a fix was introduced to have this functionality.
Note: I read that the difficulty was related to task migration between cores and how to handle aggregating different counter values from two different cores, thus the Performance Monitoring Units were disabled by default. But I will be using schedulers which do not permit task migration.
It seems that PMCTrack does enable the counters for their in their linux patch?
I attempted this hack but it did not even compile, https://github.com/thoughtpolice/enable_arm_pmu. Do not know if it has any merit.