tickadj- set time-related kernel variables
tickadj [ -Aqs ] [ -a tickadj ] [ -t tick
tickadj program reads, and optionally modifies,
several timekeeping-related variables in the running kernel, via
/dev/kmem. The particular variables it is concerned with
tick, which is the number of microseconds added to the
system time during a clock interrupt,
tickadj, which sets
the slew rate and resolution used by the
dosynctodr, which indicates to the kernels on
some machines whether they should internally adjust the system clock to
keep it in line with time-of-day clock or not.
By default, with no arguments,
tickadj reads the
variables of interest in the kernel and displays them. At the same time,
it determines an "optimal" value for the value of the
tickadj variable if the intent is to run the
xntpd Network Time Protocol (NTP) daemon, and prints this
as well. Since the operation of
tickadj when reading the
kernel mimics the operation of similar parts of the
program fairly closely, this can be useful when debugging problems with
tickadj should be run with some caution when
being used for the first time on different types of machines. The
tickadj tries to perform are not
guaranteed to work on all Unix machines and may in rare cases cause the
kernel to crash.
tickadjto the value
tickadjto an internally computed "optimal" value.
tickto the value
dosynctodrto zero, which disables the hardware time-of-year clock, a prerequisite for running the
xntpddaemon under SunOS4.
tickadjis quite verbose about what it is doing. The
-qflag tells it to shut up about everything except errors.
Fiddling with kernel variables at run time as a part of ordinary
operations is a hideous practice which is only necessary to make up for
deficiencies in the implementation of
adjtime in many
kernels and/or brokenness of the system clock in some vendors' kernels.
It would be much better if the kernels were fixed and the
program went away.