[ntp:questions] tinker step 0 (always slew) and kernel time discipline

Joe Harvell harvell at nortel.com
Thu Sep 21 16:00:10 UTC 2006

I have an application that is sensitive to step corrections and am considering using 'tinker step 0' to disable them altogether.  However, I noticed a thread on this topic in February 2005 (http://lists.ntp.isc.org/pipermail/questions/2005-February/004468.html) that suggested setting 'tinker step 0' without explicitly using 'disable kernel' will essentially yield unpredictable behavior.

So what does disable kernel do?  Does it disable the NHPFL algorithm?  Is this algorithm synonomous with the "kernel time discipline?"  So when "disable kernel" has been used, how is the clock frequency adjusted?  Also, why is the kernel time discipline disabled when a correction of > 0.5 seconds is required?

Joe Harvell

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