Commit b95d1598 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Joel Fernandes
Browse files

Revert "rcu/nocb: Fix rcuog wake-up from offline softirq" 

This reverts commit f7345ccc.

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: default avatarUsama Arif <usamaarif642@gmail.com>
Reviewed-by: default avatarJoel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarJoel Fernandes <joelagnelf@nvidia.com>
parent 9520371e

kernel/rcu/tree_nocb.h

+1 −7
Original line number Diff line number Diff line
@@ -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"));