From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: rcu@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
Josh Triplett <josh@joshtriplett.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Joel Fernandes <joel@joelfernandes.org>,
Scott Wood <swood@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH 1/5] rcu: make RCU_BOOST default on CONFIG_PREEMPT_RT
Date: Tue, 15 Dec 2020 15:16:45 +0100 [thread overview]
Message-ID: <20201215141649.796472-2-bigeasy@linutronix.de> (raw)
In-Reply-To: <20201215141649.796472-1-bigeasy@linutronix.de>
With RCU callbacks deferred to the `rcuc' thread it is more likely that
people run into OOM if the RCU reader or the thread is stalled for too
long and RCU can't continue its work.
On PREEMPT_RT this is more likely because the amount of RT tasks is
higher and the general workload involves more RT tasks.
Make RCU_BOOST default on PREEMPT_RT to ease the configuration. It can
be still disabled if someone knows better.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/rcu/Kconfig | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
index cdc57b4f6d48a..aa8cc8c977e78 100644
--- a/kernel/rcu/Kconfig
+++ b/kernel/rcu/Kconfig
@@ -188,8 +188,8 @@ config RCU_FAST_NO_HZ
config RCU_BOOST
bool "Enable RCU priority boosting"
- depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT
- default n
+ depends on (RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT) || PREEMPT_RT
+ default y if PREEMPT_RT
help
This option boosts the priority of preempted RCU readers that
block the current preemptible RCU grace period for too long.
--
2.29.2
next prev parent reply other threads:[~2020-12-15 14:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 14:16 [PATCH 0/5] A few smaller RCU related patches from the RT tree Sebastian Andrzej Siewior
2020-12-15 14:16 ` Sebastian Andrzej Siewior [this message]
2020-12-15 14:16 ` [PATCH 2/5] rcu: Use rcuc threads on PREEMPT_RT Sebastian Andrzej Siewior
2020-12-15 14:16 ` [PATCH 3/5] rcu: enable rcu_normal_after_boot by default for RT Sebastian Andrzej Siewior
2020-12-15 14:16 ` [PATCH 4/5] doc: Update RCU's requirements page about the PREEMPT_RT wiki Sebastian Andrzej Siewior
2020-12-15 14:16 ` [PATCH 5/5] doc: Use CONFIG_PREEMPTION Sebastian Andrzej Siewior
2020-12-15 18:01 ` [PATCH 0/5] A few smaller RCU related patches from the RT tree Paul E. McKenney
2020-12-15 20:47 ` Sebastian Andrzej Siewior
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