This flag will now obtain and show the processor number on which a process is running.
This change was inspired by PR129965. Initially I didn't think that the patch attached to it was correct -- it sacrificed ki_estcpu use in "cpu" for ki_lastcpu and I thought that the old functionality should be kept and the new one added to it. But I've since discovered that ki_estcpu is sched_4bsd-specific. What's worse, it represents the same thing as ki_pctcpu, except ki_pctcpu is universal -- so "%cpu" has been using it successfully. Therefore, I've decided to replace information based on ki_estcpu with information based on ki_oncpu/ki_lastcpu.
Key parts of code and manual were borrowed from top(1).
# ps -ocomm,cpu,%cpu COMMAND C %CPU getty 3 0.0 getty 3 0.0 getty 0 0.0 getty 3 0.0 getty 0 0.0 getty 1 0.0 getty 3 0.0 getty 0 0.0 ps 3 0.0 su 0 0.0 csh 0 0.0