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. _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
