[ntp:questions] Which version of Linux works best?

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Thu Mar 11 22:20:24 UTC 2010


>> Modern Linux kernels don't support PPS in the sense of RFC-whateveritis.
>>
>> There is support for an ioctl that says "wake me up when a modem signal changes".
>> gpsd uses that to provide PPS support.  I don't have any data.
>
>I believe but am not sure, that that uses an interrupt.

I think so.  But the point is that with the PPS support, the
kernel grabs a timestamp in the interrupt routine.  The ioctl
stuff just wakes up the user program so it can grab the timestamp.
On a lightly loaded system, that will probably work OK.  But if
the system gets busy, there will be more noise in the data.

-- 
These are my opinions, not necessarily my employer's.  I hate spam.




More information about the questions mailing list