Thanks, I'll try that.
I thought I had done that already by using SMP SeeSaw to isolate the process on CPU #2.
I must have made some mistakes while trying it.
Since SMP SeeSaw requires the CPU assignement to be made after launch, it is highly possible I have forgotten to change CPU during one test, and therefore, flagged this solution as "useless"

.
I'll force it on CPU #2 using imagecfg for now, and see how it goes.