+ chrony-users@chrony.tuxfamily.org On Fri, Aug 5, 2022 at 11:14 AM 심준영 <joonyoung.s...@42dot.ai> wrote:
> Hi all, > > I have a problem on my system environment using chrony and linuxptp. > > There are two machines on my local network. One is ptp4l master and > another is > ptp4l slave. The ptp4l master machine uses chrony to update system clock > and > also phc2sys updates PTP hardware clock from system clock. > > The ptp4l slave machine doesn't use chrony and any NTP daemon, it updates > system clock using phc2sys from PTP hardware clock. > > My problem is to cause too large gap between system clock and PTP hardware > clock > for a short while, whenever chrony synchronizes time from external NTP > server > (Poll is 6, so about 64 seconds) and then will affect to PTP hardware > clock and > system clock of the ptp4l slave machine. > > Are there any ideas to keep stable small gap even though using NTP like > chrony > to update system clock? > > Below is a phc2sys log from ptp4l master machine. The offset increases to > -2136ns from under 100ns when chrony synchronizes time from external NTP > server. > > ... > Aug 5 10:54:56 my-machine phc2sys: [9332.901] eth0 sys offset -39 > s2 freq -73487 delay 2250 > Aug 5 10:54:57 my-machine phc2sys: [9333.901] eth0 sys offset -53 > s2 freq -73512 delay 1875 > Aug 5 10:54:58 my-machine phc2sys: [9334.902] eth0 sys offset -15 > s2 freq -73490 delay 2250 > Aug 5 10:54:59 my-machine phc2sys: [9335.902] eth0 sys offset 76 > s2 freq -73404 delay 1750 > Aug 5 10:55:00 my-machine phc2sys: [9336.902] eth0 sys offset -11 > s2 freq -73468 delay 1875 > Aug 5 10:55:01 my-machine phc2sys: [9337.903] eth0 sys offset 29 > s2 freq -73431 delay 2000 > Aug 5 10:55:02 my-machine phc2sys: [9338.903] eth0 sys offset -38 > s2 freq -73489 delay 1875 > Aug 5 10:55:03 my-machine phc2sys: [9339.903] eth0 sys offset 4 > s2 freq -73459 delay 2000 > Aug 5 10:55:04 my-machine phc2sys: [9340.904] eth0 sys offset 17 > s2 freq -73445 delay 2000 > Aug 5 10:55:05 my-machine phc2sys: [9341.904] eth0 sys offset -15 > s2 freq -73472 delay 2000 > Aug 5 10:55:06 my-machine phc2sys: [9342.904] eth0 sys offset 0 > s2 freq -73461 delay 2000 > Aug 5 10:55:07 my-machine phc2sys: [9343.905] eth0 sys offset 16 > s2 freq -73445 delay 1875 > Aug 5 10:55:08 my-machine phc2sys: [9344.905] eth0 sys offset -23 > s2 freq -73479 delay 2000 > Aug 5 10:55:09 my-machine phc2sys: [9345.905] eth0 sys offset 2 > s2 freq -73461 delay 2000 > Aug 5 10:55:10 my-machine phc2sys: [9346.906] eth0 sys offset 33 > s2 freq -73430 delay 1751 > Aug 5 10:55:11 my-machine phc2sys: [9347.906] eth0 sys offset -62 > s2 freq -73515 delay 2125 > Aug 5 10:55:12 my-machine phc2sys: [9348.906] eth0 sys offset 8 > s2 freq -73463 delay 2000 > Aug 5 10:55:13 my-machine phc2sys: [9349.907] eth0 sys offset -2136 > s2 freq -75605 delay 2000 > Aug 5 10:55:14 my-machine phc2sys: [9350.907] eth0 sys offset -2363 > s2 freq -76473 delay 1875 > Aug 5 10:55:15 my-machine phc2sys: [9351.907] eth0 sys offset -1656 > s2 freq -76475 delay 1875 > Aug 5 10:55:16 my-machine phc2sys: [9352.908] eth0 sys offset -919 > s2 freq -76234 delay 2000 > Aug 5 10:55:17 my-machine phc2sys: [9353.908] eth0 sys offset -571 > s2 freq -76162 delay 1875 > Aug 5 10:55:18 my-machine phc2sys: [9354.908] eth0 sys offset -176 > s2 freq -75938 delay 1875 > Aug 5 10:55:19 my-machine phc2sys: [9355.909] eth0 sys offset 8 > s2 freq -75807 delay 2000 > Aug 5 10:55:20 my-machine phc2sys: [9356.909] eth0 sys offset -71 > s2 freq -75884 delay 2000 > Aug 5 10:55:21 my-machine phc2sys: [9357.909] eth0 sys offset 119 > s2 freq -75715 delay 1750 > Aug 5 10:55:22 my-machine phc2sys: [9358.910] eth0 sys offset -49 > s2 freq -75847 delay 2000 > Aug 5 10:55:23 my-machine phc2sys: [9359.910] eth0 sys offset 53 > s2 freq -75760 delay 2250 > Aug 5 10:55:24 my-machine phc2sys: [9360.911] eth0 sys offset -22 > s2 freq -75819 delay 2000 > Aug 5 10:55:25 my-machine phc2sys: [9361.911] eth0 sys offset 25 > s2 freq -75779 delay 2000 > Aug 5 10:55:26 my-machine phc2sys: [9362.912] eth0 sys offset 46 > s2 freq -75750 delay 2000 > Aug 5 10:55:27 my-machine phc2sys: [9363.912] eth0 sys offset -17 > s2 freq -75799 delay 2000 > Aug 5 10:55:28 my-machine phc2sys: [9364.912] eth0 sys offset -44 > s2 freq -75832 delay 2000 > Aug 5 10:55:29 my-machine phc2sys: [9365.913] eth0 sys offset -38 > s2 freq -75839 delay 2000 > Aug 5 10:55:30 my-machine phc2sys: [9366.913] eth0 sys offset 53 > s2 freq -75759 delay 2000 > Aug 5 10:55:31 my-machine phc2sys: [9367.913] eth0 sys offset -30 > s2 freq -75826 delay 1875 > Aug 5 10:55:32 my-machine phc2sys: [9368.914] eth0 sys offset -36 > s2 freq -75841 delay 2001 > ... > > Thanks. >
