Re: [Linuxptp-users] ptp4l results in stable master offset, but phc2sys usually see some spike in offset (10000+)

[Richard C. <ric...@gm...>]

On Sun, Feb 07, 2021 at 06:44:24AM +0000, Sean Ma wrote:
> We are using a PTP GM connecting to Intel I350 as our PHC, running Centos OS.
> 
> In the ptp4l, the master offset is always stable.
> In the phc2sys sometimes we get spike up to 10000 once or more per minute, command used: phc2sys -s <I350 NIC port> -w -m -n 44
> 
> Do we know the typical reason for this behavior?

Check if the "delay" value also jumps up.

- If so, then phc2sys is being preempted during a measurement.  You
  can mitigate this by using chrt.

- If not, the problem may be in the device driver or hardware.

Thanks,
Richard