Oracle Linux 6.6 and 7 with Unbreakable Enterprise Kernel 3 (UEK3) might panic at boot time with backtrace "__cpufreq_governor".
Affected software:
Oracle Linux 6.6/7.0 with UEK3QU4 (3.8.13-55) and any older UEK3 kernels
Workaround:
Manually reset the system.