Commit 6e16b0f7 authored Sep 16, 2021 by Frederic Weisbecker Committed by Paul E. McKenney Dec 07, 2021

rcu: Move rcu_data.cpu_no_qs.b.exp reset to rcu_export_exp_rdp()



On non-preemptible RCU, move clearing of the rcu_data structure's
->cpu_no_qs.b.exp filed to the actual expedited quiescent state report
function, matching hw preemptible RCU handles the ->exp_deferred_qs field.

This prepares for removing ->exp_deferred_qs in favor of ->cpu_no_qs.b.exp
for both preemptible and non-preemptible RCU.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

parent a4382659

kernel/rcu/tree_exp.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -256,6 +256,7 @@ static void rcu_report_exp_cpu_mult(struct rcu_node *rnp,
		static void rcu_report_exp_rdp(struct rcu_data *rdp)
		{
		WRITE_ONCE(rdp->exp_deferred_qs, false);
		WRITE_ONCE(rdp->cpu_no_qs.b.exp, false);
		rcu_report_exp_cpu_mult(rdp->mynode, rdp->grpmask, true);
		}

kernel/rcu/tree_plugin.h

+2 −4

Original line number	Diff line number	Diff line
		@@ -849,9 +849,7 @@ static void rcu_qs(void)
		trace_rcu_grace_period(TPS("rcu_sched"),
		__this_cpu_read(rcu_data.gp_seq), TPS("cpuqs"));
		__this_cpu_write(rcu_data.cpu_no_qs.b.norm, false);
		if (!__this_cpu_read(rcu_data.cpu_no_qs.b.exp))
		return;
		__this_cpu_write(rcu_data.cpu_no_qs.b.exp, false);
		if (__this_cpu_read(rcu_data.cpu_no_qs.b.exp))
		rcu_report_exp_rdp(this_cpu_ptr(&rcu_data));
		}