low HZ value causes "Time Warp Bug" (re: this Puny Pentium2
suddenly became 45% slower!)
Paul Seniura
pdseniura at techie.com
Thu May 6 14:37:20 PDT 2004
It seems this bug happens when the HZ value goes below 16
(either by compiling 'options HZ=' in kernel or setting
sysctl 'kern.hz=' in /boot/loader.conf). The computed
'ticks' value becomes too large for 2-byte int producing
crazy overflowed numbers elsewhere.
The crazyness extends to human clocks such as what KDE
uses. I mean it was visibly speeding up and showing time
to go home before it was 'really' lunchtime! Time warp!!
Something needs to check for overflow, but I bet whatever
this field is cannot easily be widend past 2-byte int?
I guess I will file a PR on this.
-- thx, Paul Seniura.
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