[$] Telling the scheduler about thermal pressure

Even with radiators and fans, a system's CPUs can overheat. When thathappens, the kernel's thermal governor will cap the maximum frequency ofthat CPU to allow it to cool. The scheduler, however, is not aware that the CPU'scapacity has changed; it may schedule more work than optimal in the currentconditions, leading to a performance degradation. Recently, TharaGopinath didsome research and posted a patch set to address this problem. Thesolution adds an interface to inform the scheduler about thermal events sothat it can assign tasks better and thus improve the overall systemperformance.