On 2013-02-26, rama...@gmail.com <rama...@gmail.com> wrote: > On Tuesday, February 26, 2013 10:57:22 AM UTC+10, unruh wrote: >> handling. And I only saw 1-2 us difference. Why are you getting 12us on >> the ldisc code? > > The 11us in my case is how long it takes to get from early in the interrupt > code in arch/x86/kernel/irq_32.c to where the time stamp is normally taken > for > the pps. > > o127.127.22.0 .PPS. 0 l 5 16 377 0.000 0.000 0.001 > 127.127.28.0 .SHM. 0 l 4 16 377 0.000 0.011 0.001 > > That is from a new kernel I have had running for around an hour. The .PPS. > time stamp is unmodified from the ppsapi and the .SHM. time stamp is taken > at the beginning of the interrupt code. Using /proc to export my time stamp > and the shm driver to feed it to ntp. > > Getting the same 11us difference I see with my normal kernel. Normally I use > the earlier time stamp because it has less jitter and is affected less by > cpu load.
Bizzare. 11us is a huge amount of time. What are you using for the ppsapi? pps-ldisk module? _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
