I have an Intel server. The CPUs are power managed between 800MHz and 3GHz, using the p_state driver. Obviously it's drawing less power and making less noise when it's down at 800Mhz.
Most of the things that are running on the server are on-demand and should execute as fast as possible (and they do) but I have one daemon that is thoroughly unimportant. It takes about 20% CPU at peak but this can last for a few hours while it processes files.
My problem is whenever this process does anything, the power state in the CPU ramps up. It uses more power and makes more noise. I want this one daemon to run at 800MHz all the time (unless anything else needs the CPU).
I could stick the whole server in powersave but I need other applications to be able to scale the CPU. Is there a sensible way I can tell whatever manages the CPU to disregard load from a particular application?