Impact when re-assigning CPU affinity

[Mariel_Donila]

Hey team,

• I want to find out if there's an impact to the network traffic if I change the CPU affinity using the fw ctl affinity command of an interface from CPU0 to CPU1?  I could not find any information about this but I suspect it should not cause any issues?
• Is it also possible to lists the most CPU demanding interface if they are sharing the same CPU? Below is our current affinity settings:

eth1-01: CPU 0
eth1-02: CPU 0
eth1-03: CPU 0
eth1-04: CPU 0
eth3-01: CPU 0
eth3-02: CPU 0
eth3-03: CPU 0

Thanks

[G_W_Albrecht]

You want answers - but here you can find much more: sk98348: Best Practices - Security Gateway Performance

[Craig_Wilkie]

We had issues around this with a cluster of IP690's running R77.30 last year. The issue showed up in that the %SI cpu  for cpu0 figure in top was very high and the affinity settings had all of our heavily used interfaces on CPU0. We manually configured the affinity to even out the network load across more cores and this had the effect of a more balanced split of %SI CPU usage across all the cores.