void
binuptime(struct bintime *bt)
void
getbinuptime(struct bintime *bt)
void
microuptime(struct timeval *tv)
void
getmicrouptime(struct timeval *tv)
void
nanouptime(struct timespec *ts)
void
getnanouptime(struct timespec *tsp)
)
and
getbinuptime()
functions store the time elapsed since boot as a
at the address specified by
bt.
The
microuptime()
and
getmicrouptime()
functions perform the same utility, but record the elapsed time as a
instead.
Similarly the
nanouptime()
and
getnanouptime()
functions store the elapsed time as a
The
binuptime(),
microuptime(),
and
nanouptime()
functions
always query the timecounter to return the current time as precisely as
possible.
Whereas
getbinuptime(),
getmicrouptime(),
and
getnanouptime()
functions are abstractions which return a less precise, but
faster to obtain, time.
The intent of the
getbinuptime(),
getmicrouptime(),
and
getnanouptime()
functions is to enforce the user's preference for timer accuracy versus
execution time.
They should be used where a precision of
1/HZ
(e.g., 10 msec on a
100HZ
machine, see
hz(9))
is acceptable or where performance is priority.