William Reich wrote:
Hi...
I am curious to understand how
dtrace can have a nanosecond timestamp
even when the hi-res-tick-timer is off
( according to /etc/system file ).
hi-res-tick and the timing you get from dtrace aren't the same thing -
setting hi-res tick increases the clock tick frequency from 100Hz to 1kHz,
which is much too slow for anything that needs to be measured more
precisely (as you observe) - this is a holdover from the time before we had
cyclics and hires-timer (not to be confused with the above), which is
basically - and very roughly - a timer that gets the best resolution the HW
can offer.
Is timestamp really that accurate when the hi-res-tick-timer is off ?
the unit is in ns, precision can be less (at least that's what I remember
from the last time I looked at this) and again depends on HW.
Michael
--
Michael Schuster http://blogs.sun.com/recursion
Recursion, n.: see 'Recursion'
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