From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
To: linux-kernel@vger.kernel.org
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>,
rcu@vger.kernel.org, "Paul E. McKenney" <paulmck@linux.ibm.com>,
frederic@kernel.org
Subject: [PATCH -rcu dev 2/3] rcu/tree: Fix issue where sometimes rcu_urgent_qs is not set on IPI
Date: Thu, 15 Aug 2019 22:53:10 -0400 [thread overview]
Message-ID: <20190816025311.241257-2-joel@joelfernandes.org> (raw)
In-Reply-To: <20190816025311.241257-1-joel@joelfernandes.org>
Sometimes I see rcu_urgent_qs is not set. This could be when the last
IPI was a long time ago, however, the grace period just started. Set
rcu_urgent_qs so the tick can indeed be stopped.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
kernel/rcu/tree.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 322b1b57967c..856d3c9f1955 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1091,6 +1091,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
if (tick_nohz_full_cpu(rdp->cpu) &&
time_after(jiffies,
READ_ONCE(rdp->last_fqs_resched) + jtsq * 3)) {
+ WRITE_ONCE(*ruqp, true);
resched_cpu(rdp->cpu);
WRITE_ONCE(rdp->last_fqs_resched, jiffies);
}
--
2.23.0.rc1.153.gdeed80330f-goog
next prev parent reply other threads:[~2019-08-16 2:53 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-16 2:53 [PATCH -rcu dev 1/3] rcu/tree: tick_dep_set/clear_cpu should accept bits instead of masks Joel Fernandes (Google)
2019-08-16 2:53 ` Joel Fernandes (Google) [this message]
2019-08-16 2:57 ` [PATCH -rcu dev 2/3] rcu/tree: Fix issue where sometimes rcu_urgent_qs is not set on IPI Joel Fernandes
2019-08-16 2:53 ` [PATCH -rcu dev 3/3] RFC: rcu/tree: Read dynticks_nmi_nesting in advance Joel Fernandes (Google)
2019-08-16 16:24 ` Joel Fernandes
2019-08-16 16:52 ` Paul E. McKenney
2019-08-16 17:07 ` Joel Fernandes
2019-08-16 17:30 ` Paul E. McKenney
2019-08-19 12:59 ` Frederic Weisbecker
2019-08-19 14:22 ` Joel Fernandes
2019-08-19 14:41 ` Paul E. McKenney
2019-08-19 15:46 ` Joel Fernandes
2019-08-19 16:17 ` Paul E. McKenney
2019-08-19 14:40 ` Paul E. McKenney
2019-08-16 2:59 ` [PATCH v2 -rcu dev 2/3] rcu/tree: Fix issue where sometimes rcu_urgent_qs is not set on IPI Joel Fernandes (Google)
2019-08-16 17:04 ` Paul E. McKenney
2019-08-16 17:25 ` [PATCH -rcu dev 1/3] rcu/tree: tick_dep_set/clear_cpu should accept bits instead of masks Paul E. McKenney
2019-08-16 17:35 ` Joel Fernandes
2019-08-19 12:38 ` Frederic Weisbecker
2019-08-19 14:46 ` Paul E. McKenney
2019-08-19 16:32 ` Frederic Weisbecker
2019-08-19 16:44 ` Paul E. McKenney
2019-08-20 12:08 ` Frederic Weisbecker
2019-08-20 14:44 ` Paul E. McKenney
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