[ntp:questions] When is the kernel-mode time-stamping used under Windows? Must one add the type 22 driver line?

David Taylor david-taylor at blueyonder.co.uk.invalid
Sat Jan 26 19:00:55 UTC 2013


I've tried to follow this in the code, but it's beyond me, I'm afraid!

1 - the modified serialpps.sys device driver is installed
2 - the support DLL is present
3 - the environment variable points to the support DLL

is it necessary to add the ATOM driver to the ntp.conf file?  I.e. do 
you /need/ a line such as:

   server  minpoll 4

to ensure that the kernel-mode driver is used?  My testing on one 
Windows-8/64 system suggest that the driver is used whether or not a 
type 22 driver is specified, given the conditions above.  I'm not 
complaining about this, just wondering whether anyone may be able to 
confirm that from the source code.

The question arose because adding the line made no improvement to the 
jitter, which initially made me think that the driver was not being 
used, but further tests suggest it's the opposite - that the driver is 
being used whether you asked for it explicitly or not.  Of course, given 
(1)..(3) above does rather suggest you want the kernel-mode, so the 
behaviour makes sense, even if it is a little confusing.

[Yes, FreeBSD and Linux behave differently.]
Web: http://www.satsignal.eu

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