From 45975c7d21a1c0aba97e3d8007e2a7c123145748 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 2 Jul 2018 14:30:37 -0700 Subject: rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds Now that RCU-preempt knows about preemption disabling, its implementation of synchronize_rcu() works for synchronize_sched(), and likewise for the other RCU-sched update-side API members. This commit therefore confines the RCU-sched update-side code to CONFIG_PREEMPT=n builds, and defines RCU-sched's update-side API members in terms of those of RCU-preempt. This means that any given build of the Linux kernel has only one update-side flavor of RCU, namely RCU-preempt for CONFIG_PREEMPT=y builds and RCU-sched for CONFIG_PREEMPT=n builds. This in turn means that kernels built with CONFIG_RCU_NOCB_CPU=y have only one rcuo kthread per CPU. Signed-off-by: Paul E. McKenney Cc: Andi Kleen --- include/linux/rcupdate.h | 14 ++++---------- include/linux/rcutiny.h | 7 +++++++ include/linux/rcutree.h | 7 ++++++- 3 files changed, 17 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 8d5740edd63c..94474bb6b5c4 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -49,11 +49,11 @@ /* Exported common interfaces */ -#ifdef CONFIG_PREEMPT_RCU -void call_rcu(struct rcu_head *head, rcu_callback_t func); -#else /* #ifdef CONFIG_PREEMPT_RCU */ +#ifdef CONFIG_TINY_RCU #define call_rcu call_rcu_sched -#endif /* #else #ifdef CONFIG_PREEMPT_RCU */ +#else +void call_rcu(struct rcu_head *head, rcu_callback_t func); +#endif void call_rcu_sched(struct rcu_head *head, rcu_callback_t func); void synchronize_sched(void); @@ -92,11 +92,6 @@ static inline void __rcu_read_unlock(void) preempt_enable(); } -static inline void synchronize_rcu(void) -{ - synchronize_sched(); -} - static inline int rcu_preempt_depth(void) { return 0; @@ -107,7 +102,6 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ void rcu_init(void); extern int rcu_scheduler_active __read_mostly; -void rcu_sched_qs(void); void rcu_check_callbacks(int user); void rcu_report_dead(unsigned int cpu); void rcutree_migrate_callbacks(int cpu); diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index ac26c27ccde8..df2c0895c5e7 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -36,6 +36,11 @@ static inline int rcu_dynticks_snap(struct rcu_dynticks *rdtp) /* Never flag non-existent other CPUs! */ static inline bool rcu_eqs_special_set(int cpu) { return false; } +static inline void synchronize_rcu(void) +{ + synchronize_sched(); +} + static inline unsigned long get_state_synchronize_rcu(void) { return 0; @@ -94,6 +99,8 @@ static inline void kfree_call_rcu(struct rcu_head *head, call_rcu(head, func); } +void rcu_sched_qs(void); + static inline void rcu_softirq_qs(void) { rcu_sched_qs(); diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index f7a41323aa54..0c44720f0e84 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -45,14 +45,19 @@ static inline void rcu_virt_note_context_switch(int cpu) rcu_note_context_switch(false); } +void synchronize_rcu(void); static inline void synchronize_rcu_bh(void) { synchronize_rcu(); } -void synchronize_sched_expedited(void); void synchronize_rcu_expedited(void); +static inline void synchronize_sched_expedited(void) +{ + synchronize_rcu_expedited(); +} + void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func); /** -- cgit v1.2.3