From: Zqiang <qiang1.zhang@xxxxxxxxx> The per-CPU "rcuc" kthreads are used only by kernels booted with rcutree.use_softirq=0, but they are nevertheless unconditionally created by kernels built with CONFIG_RCU_BOOST=y. This results in "rcuc" kthreads being created that are never actually used. This commit therefore refrains from creating these kthreads unless the kernel is actually booted with rcutree.use_softirq=0. Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- kernel/rcu/tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a4c25a6283b0b..4e5e37e5ee3c9 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2894,7 +2894,7 @@ static int __init rcu_spawn_core_kthreads(void) for_each_possible_cpu(cpu) per_cpu(rcu_data.rcu_cpu_has_work, cpu) = 0; - if (!IS_ENABLED(CONFIG_RCU_BOOST) && use_softirq) + if (use_softirq) return 0; WARN_ONCE(smpboot_register_percpu_thread(&rcu_cpu_thread_spec), "%s: Could not start rcuc kthread, OOM is now expected behavior\n", __func__); -- 2.31.1.189.g2e36527f23
