diff options
Diffstat (limited to 'debian/patches-rt/0071-rcu-Make-RCU_BOOST-default-on-CONFIG_PREEMPT_RT.patch')
| -rw-r--r-- | debian/patches-rt/0071-rcu-Make-RCU_BOOST-default-on-CONFIG_PREEMPT_RT.patch | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/debian/patches-rt/0071-rcu-Make-RCU_BOOST-default-on-CONFIG_PREEMPT_RT.patch b/debian/patches-rt/0071-rcu-Make-RCU_BOOST-default-on-CONFIG_PREEMPT_RT.patch new file mode 100644 index 000000000..c6be2d81c --- /dev/null +++ b/debian/patches-rt/0071-rcu-Make-RCU_BOOST-default-on-CONFIG_PREEMPT_RT.patch @@ -0,0 +1,41 @@ +From b9c110646f281f521cc06039710f979b363478b9 Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Tue, 15 Dec 2020 15:16:45 +0100 +Subject: [PATCH 071/323] rcu: Make RCU_BOOST default on CONFIG_PREEMPT_RT +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz + +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(-) + +diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig +index cd6e11403f1b..0c71197857f6 100644 +--- a/kernel/rcu/Kconfig ++++ b/kernel/rcu/Kconfig +@@ -189,8 +189,8 @@ 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. +-- +2.43.0 + |