[ntp:questions] Re: OS recomendations for stratum 2 clocks

Brad Knowles brad at stop.mail-abuse.org
Sun Sep 11 13:27:12 UTC 2005


At 10:22 PM -0400 2005-09-10, Danny Mayer wrote:

>>  There is one trick that never gets mentioned: On OSs that support this,
>>  give the NTP daemon the highest realtime priority, exceeding even parts
>>  of the OS, rather than its usual default priority.
>
>  I believe that NTP does this already in it's code.

	It has the "-N" option, yes.  However, that is not used by 
default, although it can always be specified on the command line.

	What I believe that Joseph Gwinn was talking about was running at 
actual real-time priority (rtprio), which causes ntpd to actually run 
at higher priority than most parts of the OS itself, which is a 
feature that only some OSes support.  He is right that this can be 
very useful, and can help eliminate lost clock interrupts and other 
sources of internal jitter, although it is rarely necessary.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.



More information about the questions mailing list