`tuned-adm recommend` shouldn’t recommend profiles with unsupported CPU governors

[da2x]

_get_available_governors() can determine which governors a CPU supports. This information should be used in tuned-adm recommend so it doesn’t recommend unsupported profiles.

I like the balanced profile, but all my CPUs (five different generation mobile and desktop Intels) only support powersave and performance governors. I suspect this will be true for a lot of desktop/laptop usecases. To provide some useful profile, maybe the desktop profile could be adjusted to inherit balanced as it does today, but set CPU governor to performance — and a new lapto profile match balanced but use the powersave governor. —that is at least the profiles I’ve created for myself based on this thinking and the governors supported available to my consumer grade hardware.

[olysonek]

I think the way to go here is to fix the profiles themselves to find out which governors are available, and to choose the most appropriate governor for the intended workload. So for example if the conservative governor, set by the balanced profile, is not available, then the powersave governor should be set, as that governor is similar.

I implemented this here: https://github.com/redhat-performance/tuned/pull/165