diff options
| -rw-r--r-- | include/linux/rcupdate.h | 1 | ||||
| -rw-r--r-- | init/Kconfig | 13 | ||||
| -rw-r--r-- | kernel/rcu/update.c | 11 |
3 files changed, 24 insertions, 1 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 57a4d1f73a00..b9f039b11d31 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -278,6 +278,7 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ void rcu_init(void); +void rcu_end_inkernel_boot(void); void rcu_sched_qs(void); void rcu_bh_qs(void); void rcu_check_callbacks(int user); diff --git a/init/Kconfig b/init/Kconfig index f5dbc6d4261b..9a0592516f48 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -791,6 +791,19 @@ config RCU_NOCB_CPU_ALL endchoice +config RCU_EXPEDITE_BOOT + bool + default n + help + This option enables expedited grace periods at boot time, + as if rcu_expedite_gp() had been invoked early in boot. + The corresponding rcu_unexpedite_gp() is invoked from + rcu_end_inkernel_boot(), which is intended to be invoked + at the end of the kernel-only boot sequence, just before + init is exec'ed. + + Accept the default if unsure. + endmenu # "RCU Subsystem" config BUILD_BIN2C diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 5f850823c187..7b12466f90bc 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -64,7 +64,8 @@ module_param(rcu_expedited, int, 0); #ifndef CONFIG_TINY_RCU -static atomic_t rcu_expedited_nesting; +static atomic_t rcu_expedited_nesting = + ATOMIC_INIT(IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT) ? 1 : 0); /* * Should normal grace-period primitives be expedited? Intended for @@ -109,6 +110,14 @@ EXPORT_SYMBOL_GPL(rcu_unexpedite_gp); #endif /* #ifndef CONFIG_TINY_RCU */ +/* + * Inform RCU of the end of the in-kernel boot sequence. + */ +void rcu_end_inkernel_boot(void) +{ + if (IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT)) + rcu_unexpedite_gp(); +} #ifdef CONFIG_PREEMPT_RCU |