[$] Toward better CPU load estimation

"Load tracking" refers to the kernel's attempts to track how much load eachrunning process will put on the system's CPUs. Good load tracking canyield reasonable predictions about the near-future demands on the system;those, in turn, can be used to optimize the placement of processes and theselection of CPU-frequency parameters. Obviously, poor load tracking willlead to less-than-optimal results. While achieving perfection in load trackingseems unlikely for now, it appears that it is possible to do better thancurrent kernels do. The utilization estimationpatch set from Patrick Bellasi is the latest in a series of efforts tomake the scheduler's load tracking work well with a wider variety ofworkloads.