From b95d15980a0f2727a421392ebb50fc6338e43b02 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 31 Dec 2024 18:07:12 +0100 Subject: [PATCH] Revert "rcu/nocb: Fix rcuog wake-up from offline softirq" This reverts commit f7345ccc62a4b880cf76458db5f320725f28e400. swake_up_one_online() has been removed because hrtimers can now assign a proper online target to hrtimers queued from offline CPUs. Therefore remove the related hackery. Link: https://lore.kernel.org/all/20241231170712.149394-4-frederic@kernel.org/ Reviewed-by: Usama Arif Reviewed-by: Joel Fernandes Signed-off-by: Frederic Weisbecker Signed-off-by: Joel Fernandes --- kernel/rcu/tree_nocb.h | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h index 109bc2df1d9a..1596812f7f12 100644 --- a/kernel/rcu/tree_nocb.h +++ b/kernel/rcu/tree_nocb.h @@ -554,19 +554,13 @@ static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone, rcu_nocb_unlock(rdp); wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE_LAZY, TPS("WakeLazy")); - } else if (!irqs_disabled_flags(flags) && cpu_online(rdp->cpu)) { + } else if (!irqs_disabled_flags(flags)) { /* ... if queue was empty ... */ rcu_nocb_unlock(rdp); wake_nocb_gp(rdp, false); trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeEmpty")); } else { - /* - * Don't do the wake-up upfront on fragile paths. - * Also offline CPUs can't call swake_up_one_online() from - * (soft-)IRQs. Rely on the final deferred wake-up from - * rcutree_report_cpu_dead() - */ rcu_nocb_unlock(rdp); wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE, TPS("WakeEmptyIsDeferred")); -- 2.25.1