this is with kernel 6.10.2 I have these options set on the boot command line: isolcpus=0,1,2 nohz_full=1,2 rcu_nocbs=1,2 $ ps -eo pid,cpuid,comm | grep rcuog 18 3 rcuog/0 38 0 rcuog/2 I do not understand why a rcuog task is spawn for cpu0. I would have expected to have one for cpu1. I do have a 31 3 rcuos/1 I am not familiar enough with rcu to know what rcuos is for. the absence of of rcuog/1 is causing rcu_irq_work_resched() to raise an interrupt every 2-3 seconds on cpu1. I am currently reading rcu/tree_nocb.h to try to make sense of what I am seeing but I am pinging the rcu list just in case what I am seeing would be immediately obvious to one of you... thank you,