Sadly, ARM performance counters are masked on Xen. For a decidedly more pleasant timing experience, we should get that working, but for the time being, CNTVCT and the bootstrap code provide something half-way decent.
Many thanks to @talex5 who spent some hours in front of my monitor while we were trying to figure out why exactly the performance counter readings always return 0. (Becausereasons.)
This is not quite the ideal state for ARM, but pending reactivation of xentropyd and hopefully full perf counters, it's a solid stop-gap measure.
hannesm
commented
9 years ago
Sadly, ARM performance counters are masked on Xen. For a decidedly more pleasant timing experience, we should get that working, but for the time being,
CNTVCTand the bootstrap code provide something half-way decent.Many thanks to @talex5 who spent some hours in front of my monitor while we were trying to figure out why exactly the performance counter readings always return
0. (Because reasons.)This is not quite the ideal state for ARM, but pending reactivation of
xentropydand hopefully full perf counters, it's a solid stop-gap measure.