[ntp:questions] Failed to test leapsecond's handling

Marco Marongiu brontolinux at gmail.com
Mon Mar 12 16:08:47 UTC 2012

Hi Martin, all

On 12/03/12 12:16, Martin Burnicki wrote:
> In my post from the earlier thread I wrote:
>> > Then you should set UTC time on that server close to (maybe 1 or 2 hours 
>> > before) midnight for the correct leap second date, e.g. 22:00 UTC on 
>> > June 30, 2012, and start ntpd on the server.

Erm... I know, but I couldn't leave two hours between each two tests, so
I was trying to find a shorter working interval. Unfortunately, when
they didn't work, this didn't come to mind immediately.

>> > I don't know if leap seconds are handled better in more recent kernels.
> A very quick look at the sources of some Linux kernel versions seems to
> indicate that the time interpolation during the leap second has been
> removed and replaced by simply stepping the clock back.
> Appearingly this has happened starting with kernel 2.6.23, where the
> function time_interpolator_update() isn't called anymore by the leap second
> handling code in  kernel/time/ntp.c.
> I haven't made some tests to verify that 2.6.22 still interpolates, but
> 2.6.23 does not, though.

I have found this, not sure how much it is related:


I am rather curious why they moved away from the advised handling to go
back to the stepped approach...

-- bronto

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