Hi All Currently, I have tested as follows: runqemu kvm slirp nographic qemuparams="-m 2048 -smp 4" bootparams="isolcpus=2,3 nohz_full=2,3 rcu_nocbs=2,3 rcutree.dump_tree=1, rcu_nocb_poll" -d rcu: Offload RCU callbacks from CPUs: 2-3. rcu: Poll for callbacks from no-CBs CPUs. rcu: rcu_organize_nocb_kthreads: No-CB GP kthread CPU 0: 1 (rcuog/0) rcu: rcu_organize_nocb_kthreads: No-CB GP kthread CPU 2: 3 (rcuog/2) but I find the rt-fifo rcuog/0 kthreads always doing polling, but due to the my_rdp->nocb_head_rdp always is empty, this doesn't do the actual thing, Is it possible that we do not polling when the nocb_head_rdp linked list is empty, and polling when it is not empty. Any thought? Thanks Zqiang
