What were you trying to do that didn't work?

When generate the TCP background traffic on interface via iperf, the offset of ptp4l running on this interface is larger and more unstable than no traffic.

Without TCP traffic:

...

ptp4l[2593.842]: master offset         13 s2 freq     +22 path delay       964
ptp4l[2594.830]: master offset         -5 s2 freq      +8 path delay       969
ptp4l[2595.833]: master offset          4 s2 freq     +16 path delay       966
ptp4l[2596.830]: master offset          4 s2 freq     +17 path delay       968
ptp4l[2597.837]: master offset          3 s2 freq     +17 path delay       968
ptp4l[2598.834]: master offset         -5 s2 freq     +10 path delay       969
ptp4l[2599.833]: master offset         -1 s2 freq     +13 path delay       969
ptp4l[2600.830]: master offset          2 s2 freq     +15 path delay       969
ptp4l[2601.841]: master offset          2 s2 freq     +16 path delay       969
ptp4l[2602.830]: master offset          0 s2 freq     +15 path delay       970
ptp4l[2603.880]: master offset         -7 s2 freq      +8 path delay       971
ptp4l[2604.835]: master offset          3 s2 freq     +15 path delay       971
ptp4l[2605.831]: master offset          2 s2 freq     +15 path delay       971
ptp4l[2606.831]: master offset         -1 s2 freq     +13 path delay       971
ptp4l[2607.831]: master offset         -3 s2 freq     +11 path delay       970
ptp4l[2608.831]: master offset          7 s2 freq     +20 path delay       970
ptp4l[2609.831]: master offset         -1 s2 freq     +14 path delay       971
ptp4l[2610.841]: master offset         -4 s2 freq     +11 path delay       970
ptp4l[2611.842]: master offset          2 s2 freq     +15 path delay       970
ptp4l[2612.914]: master offset          3 s2 freq     +17 path delay       969
ptp4l[2613.833]: master offset          1 s2 freq     +16 path delay       969

...

With TCP traffic:

ptp4l[5885.838]: master offset     -68714 s2 freq  -65967 path delay     70353
ptp4l[5886.833]: master offset      65706 s2 freq  +47839 path delay      1523
ptp4l[5887.833]: master offset     -50854 s2 freq  -49009 path delay     70353
ptp4l[5888.847]: master offset      -1918 s2 freq  -15329 path delay     70353
ptp4l[5889.833]: master offset     -54911 s2 freq  -68898 path delay    139184
ptp4l[5890.897]: master offset      13952 s2 freq  -16508 path delay    139184
ptp4l[5891.847]: master offset     171522 s2 freq +145247 path delay      1523
ptp4l[5892.833]: master offset      28606 s2 freq  +53788 path delay      1523
ptp4l[5893.833]: master offset     -94072 s2 freq  -60308 path delay     70353
ptp4l[5894.843]: master offset     -33841 s2 freq  -28299 path delay     70353
ptp4l[5895.833]: master offset      -5200 s2 freq   -9810 path delay     70353
ptp4l[5896.833]: master offset     -98273 s2 freq -104443 path delay    173260
ptp4l[5897.834]: master offset      37405 s2 freq   +1753 path delay    141975
ptp4l[5898.833]: master offset      35776 s2 freq  +11346 path delay    141975
ptp4l[5899.880]: master offset      24449 s2 freq  +10751 path delay    141975
ptp4l[5900.847]: master offset    -141848 s2 freq -148211 path delay    297514
ptp4l[5901.833]: master offset      26866 s2 freq  -22051 path delay    274755
ptp4l[5902.836]: master offset      49028 s2 freq   +8170 path delay    274755
ptp4l[5903.834]: master offset      40974 s2 freq  +14825 path delay    274755
ptp4l[5904.837]: master offset      26177 s2 freq  +12320 path delay    274755
ptp4l[5905.838]: master offset      13855 s2 freq   +7851 path delay    274755
ptp4l[5906.848]: master offset     114959 s2 freq +113112 path delay    165794
ptp4l[5907.834]: master offset      17666 s2 freq  +50306 path delay    151620
ptp4l[5908.903]: master offset       -521 s2 freq  +37419 path delay    119419
ptp4l[5909.834]: master offset     -38827 s2 freq   -1043 path delay    119419
ptp4l[5910.834]: master offset     -37826 s2 freq  -11690 path delay    119419

Please provide the package NVR for which bug is seen:

1. uname -r

5.14.0-460.el9.x86_64

1. rpm -q linuxptp

linuxptp-4.2-2.el9.x86_64

How reproducible:

always

Steps to reproduce

1. Running iperf:  iperf3 -c 192.168.11.50 -t 1800 
2. Running ptp4l and observe offset
3.  

Expected results

offset is stable

Actual results

offset is unstable