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Message-Id: <20211202001040.3126390-2-paulmck@kernel.org>
Date: Wed, 1 Dec 2021 16:10:35 -0800
From: "Paul E. McKenney" <paulmck@...nel.org>
To: rcu@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, kernel-team@...com, mingo@...nel.org,
jiangshanlai@...il.com, akpm@...ux-foundation.org,
mathieu.desnoyers@...icios.com, josh@...htriplett.org,
tglx@...utronix.de, peterz@...radead.org, rostedt@...dmis.org,
dhowells@...hat.com, edumazet@...gle.com, fweisbec@...il.com,
oleg@...hat.com, joel@...lfernandes.org,
Frederic Weisbecker <frederic@...nel.org>,
"Paul E . McKenney" <paulmck@...nel.org>
Subject: [PATCH rcu 2/7] rcu: Move rcu_data.cpu_no_qs.b.exp reset to rcu_export_exp_rdp()
From: Frederic Weisbecker <frederic@...nel.org>
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@...nel.org>
Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
---
kernel/rcu/tree_exp.h | 1 +
kernel/rcu/tree_plugin.h | 6 ++----
2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index f3947c49eee71..6c6eb32203852 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -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);
}
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 983619ba86656..1e4b4e7630735 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -849,10 +849,8 @@ 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);
- rcu_report_exp_rdp(this_cpu_ptr(&rcu_data));
+ if (__this_cpu_read(rcu_data.cpu_no_qs.b.exp))
+ rcu_report_exp_rdp(this_cpu_ptr(&rcu_data));
}
/*
--
2.31.1.189.g2e36527f23
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