From: Zqiang <qiang1.zhang@xxxxxxxxx> The rcu_boost_kthread_setaffinity() function is invoked at rcutree_online_cpu() and rcutree_offline_cpu() time, early in the online timeline and late in the offline timeline, respectively. It is also invoked from rcutree_dead_cpu(), however, in the absence of userspace manipulations (for which userspace must take responsibility), this call is redundant with that from rcutree_offline_cpu(). This redundancy can be demonstrated by printing out the relevant cpumasks This commit therefore removes the call to rcu_boost_kthread_setaffinity() from rcutree_dead_cpu(). Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- kernel/rcu/tree.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 80b84ae285b41..89313c7c17b62 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4076,15 +4076,10 @@ static void rcu_cleanup_dead_rnp(struct rcu_node *rnp_leaf) */ int rcutree_dead_cpu(unsigned int cpu) { - struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); - struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */ - if (!IS_ENABLED(CONFIG_HOTPLUG_CPU)) return 0; WRITE_ONCE(rcu_state.n_online_cpus, rcu_state.n_online_cpus - 1); - /* Adjust any no-longer-needed kthreads. */ - rcu_boost_kthread_setaffinity(rnp, -1); // Stop-machine done, so allow nohz_full to disable tick. tick_dep_clear(TICK_DEP_BIT_RCU); return 0; -- 2.31.1.189.g2e36527f23