cpu ticks) has some imprecision and, worse, huge timestep (about
20 minutes on 4GHz CPU) near 53.4 days of elapsed time.
kern_time.c/cputick2timespec() (it is used for clock_gettime() for
querying process or thread consumed cpu time) Uses cputick2usec()
and then needlessly converting usec to nsec, obviously losing
precision even with fixed cputick2usec().
kern_time.c/kern_clock_getres() uses some weird (anyway wrong)
formula for getting cputick resolution.
PR: 262215
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D34558
bb53dd56c3