There is a new option to cyclictest to detect smis, that needs to read the msr and cpuid registers. Bugzilla 1341783 creates a udev rule to give the group "realtime" access to these registers, but this isn't sufficient. Programs that require the access need the cap_sys_rawio capability
Fixed in rt-tests-1.0-3 and up
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-2391.html