[ntp:hackers] More I/O

David L. Mills mills at udel.edu
Tue Feb 15 10:26:22 PST 2005


I have  Solaris and FreeBSD machines set up with substantially the same 
radio and I/O configuration and current ntp-dev code. Both refclocks 
send serial timecodes once per second. After the first ten lines or so 
the Solaris machine stops delivering timecodes to the driver, although I 
can confirm with another terminal that the clock is sending them. It 
seems to work better on the freebie, but still goes off the rails after 
some hours.

 From all I can see here, it looks like the timecodes are accumulating 
in kernel buffers, but not being delivered to the driver. In principle, 
if the time was stamped in the buffer structure at the time the timecode 
is recieved, there would be no large error. This does not seem to be the 
case, as the driver shows huge errors after an hour or so. I conclude 
the characters are sitting for a long time before ntpd scarfs them up 
and stamps the time. Does this help? I tried to tease out the code, but 
it is so obscured by ifdefs and weeds that I geve up.


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