From: Sebastian Andrzej Siewior Date: Fri, 21 Mar 2014 20:19:05 +0100 Subject: [PATCH 044/342] rcu: make RCU_BOOST default on RT Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=3c6db36bde45dd585557217b67660ac13aff8c9e Since it is no longer invoked from the softirq people run into OOM more often if the priority of the RCU thread is too low. Making boosting default on RT should help in those case and it can be switched off if someone knows better. Signed-off-by: Sebastian Andrzej Siewior --- kernel/rcu/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig index 644264be90f0..a243a78ff38c 100644 --- a/kernel/rcu/Kconfig +++ b/kernel/rcu/Kconfig @@ -190,8 +190,8 @@ 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_FULL + default y if PREEMPT_RT_FULL help This option boosts the priority of preempted RCU readers that block the current preemptible RCU grace period for too long.