mirror of
https://github.com/linuxkit/linuxkit.git
synced 2025-09-17 15:51:17 +00:00
35 lines
1.4 KiB
Diff
35 lines
1.4 KiB
Diff
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
Date: Tue, 15 Dec 2020 15:16:45 +0100
|
|
Subject: [PATCH 1/5] rcu: Make RCU_BOOST default on CONFIG_PREEMPT_RT
|
|
|
|
On PREEMPT_RT kernels, RCU callbacks are deferred to the `rcuc' kthread.
|
|
This can stall RCU grace periods due to lengthy preemption not only of RCU
|
|
readers but also of 'rcuc' kthreads, either of which prevent grace periods
|
|
from completing, which can in turn result in OOM. Because PREEMPT_RT
|
|
kernels have more kthreads that can block grace periods, it is more
|
|
important for such kernels to enable RCU_BOOST.
|
|
|
|
This commit therefore makes RCU_BOOST the default on PREEMPT_RT.
|
|
RCU_BOOST can still be manually disabled if need be.
|
|
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
kernel/rcu/Kconfig | 4 ++--
|
|
1 file changed, 2 insertions(+), 2 deletions(-)
|
|
|
|
--- 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.
|