[ntp:questions] Clock jumps when refclock used

Dave Hart davehart at gmail.com
Tue Apr 17 09:52:13 UTC 2012

On Mon, Apr 16, 2012 at 03:08, A C <agcarver+ntp at acarver.net> wrote:
> On 4/15/2012 14:16, A C wrote:
>> I have a couple more recent examples of fuzz messages (still using the
>> Internet only configuration):
>> 14 Apr 08:59:56 ntpd[11057]: ts_min 1334393996.509276921 ts_prev
>> 1334393996.509171929 ts 1334393996.518274219
>> 14 Apr 08:59:56 ntpd[11057]: sys_fuzz 104992 nsec, this fuzz
>> 0.000076449, prior 0.000007028
>> 14 Apr 08:59:56 ntpd[11057]: get_systime prev result 0xd333bb0c.84e97365
>> is 0.000836508 later than 0xd333bb0c.84b2a11e

Thanks for the examples.  See comments in


for some detailed comments, but basically I think these are mostly
false positives due to get_systime() being re-entered, which is unsafe
when using statics to maintain previous-call state as these checks are

Thanks also to Hal Murray and others who have provided examples of
these warnings, which should become much rarer soon.

Dave Hart

Dave Hart

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