From 709fdce7545c978e69f52eb19082ea3af44332f5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 3 Jul 2018 10:44:44 -0700 Subject: [PATCH] rcu: Express Tiny RCU updates in terms of RCU rather than RCU-sched This commit renames Tiny RCU functions so that the lowest level of functionality is RCU (e.g., synchronize_rcu()) rather than RCU-sched (e.g., synchronize_sched()). This provides greater naming compatibility with Tree RCU, which will in turn permit more LoC removal once the RCU-sched and RCU-bh update-side API is removed. Signed-off-by: Paul E. McKenney [ paulmck: Fix Tiny call_rcu()'s EXPORT_SYMBOL() in response to a bug report from kbuild test robot. ] --- include/linux/rcupdate.h | 12 +++++----- include/linux/rcutiny.h | 34 +++++++++++++++------------- include/linux/rcutree.h | 1 - kernel/rcu/tiny.c | 48 ++++++++++++++++++++-------------------- 4 files changed, 48 insertions(+), 47 deletions(-) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 94474bb6b5c4..1207c6c9bd8b 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -49,15 +49,14 @@ /* Exported common interfaces */ -#ifdef CONFIG_TINY_RCU -#define call_rcu call_rcu_sched -#else -void call_rcu(struct rcu_head *head, rcu_callback_t func); +#ifndef CONFIG_TINY_RCU +void synchronize_sched(void); +void call_rcu_sched(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); +void call_rcu(struct rcu_head *head, rcu_callback_t func); void rcu_barrier_tasks(void); +void synchronize_rcu(void); static inline void call_rcu_bh(struct rcu_head *head, rcu_callback_t func) { @@ -68,7 +67,6 @@ static inline void call_rcu_bh(struct rcu_head *head, rcu_callback_t func) void __rcu_read_lock(void); void __rcu_read_unlock(void); -void synchronize_rcu(void); /* * Defined as a macro as it is a very low level header included from diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index df2c0895c5e7..e66fb8bc2127 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -36,9 +36,9 @@ 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) +static inline void synchronize_sched(void) { - synchronize_sched(); + synchronize_rcu(); } static inline unsigned long get_state_synchronize_rcu(void) @@ -61,16 +61,11 @@ static inline void cond_synchronize_sched(unsigned long oldstate) might_sleep(); } -static inline void synchronize_rcu_expedited(void) -{ - synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */ -} +extern void rcu_barrier(void); -extern void rcu_barrier_sched(void); - -static inline void rcu_barrier(void) +static inline void rcu_barrier_sched(void) { - rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */ + rcu_barrier(); /* Only one CPU, so only one list of callbacks! */ } static inline void rcu_barrier_bh(void) @@ -88,27 +83,36 @@ static inline void synchronize_rcu_bh_expedited(void) synchronize_sched(); } +static inline void synchronize_rcu_expedited(void) +{ + synchronize_sched(); +} + static inline void synchronize_sched_expedited(void) { synchronize_sched(); } -static inline void kfree_call_rcu(struct rcu_head *head, - rcu_callback_t func) +static inline void call_rcu_sched(struct rcu_head *head, rcu_callback_t func) +{ + call_rcu(head, func); +} + +static inline void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) { call_rcu(head, func); } -void rcu_sched_qs(void); +void rcu_qs(void); static inline void rcu_softirq_qs(void) { - rcu_sched_qs(); + rcu_qs(); } #define rcu_note_context_switch(preempt) \ do { \ - rcu_sched_qs(); \ + rcu_qs(); \ rcu_tasks_qs(current); \ } while (0) diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 0c44720f0e84..6d30a0809300 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -45,7 +45,6 @@ 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(); diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index cadcf63c4889..30826fb6e438 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -46,25 +46,25 @@ struct rcu_ctrlblk { }; /* Definition for rcupdate control block. */ -static struct rcu_ctrlblk rcu_sched_ctrlblk = { - .donetail = &rcu_sched_ctrlblk.rcucblist, - .curtail = &rcu_sched_ctrlblk.rcucblist, +static struct rcu_ctrlblk rcu_ctrlblk = { + .donetail = &rcu_ctrlblk.rcucblist, + .curtail = &rcu_ctrlblk.rcucblist, }; -void rcu_barrier_sched(void) +void rcu_barrier(void) { - wait_rcu_gp(call_rcu_sched); + wait_rcu_gp(call_rcu); } -EXPORT_SYMBOL(rcu_barrier_sched); +EXPORT_SYMBOL(rcu_barrier); /* Record an rcu quiescent state. */ -void rcu_sched_qs(void) +void rcu_qs(void) { unsigned long flags; local_irq_save(flags); - if (rcu_sched_ctrlblk.donetail != rcu_sched_ctrlblk.curtail) { - rcu_sched_ctrlblk.donetail = rcu_sched_ctrlblk.curtail; + if (rcu_ctrlblk.donetail != rcu_ctrlblk.curtail) { + rcu_ctrlblk.donetail = rcu_ctrlblk.curtail; raise_softirq(RCU_SOFTIRQ); } local_irq_restore(flags); @@ -79,7 +79,7 @@ void rcu_sched_qs(void) void rcu_check_callbacks(int user) { if (user) - rcu_sched_qs(); + rcu_qs(); } /* Invoke the RCU callbacks whose grace period has elapsed. */ @@ -90,17 +90,17 @@ static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused /* Move the ready-to-invoke callbacks to a local list. */ local_irq_save(flags); - if (rcu_sched_ctrlblk.donetail == &rcu_sched_ctrlblk.rcucblist) { + if (rcu_ctrlblk.donetail == &rcu_ctrlblk.rcucblist) { /* No callbacks ready, so just leave. */ local_irq_restore(flags); return; } - list = rcu_sched_ctrlblk.rcucblist; - rcu_sched_ctrlblk.rcucblist = *rcu_sched_ctrlblk.donetail; - *rcu_sched_ctrlblk.donetail = NULL; - if (rcu_sched_ctrlblk.curtail == rcu_sched_ctrlblk.donetail) - rcu_sched_ctrlblk.curtail = &rcu_sched_ctrlblk.rcucblist; - rcu_sched_ctrlblk.donetail = &rcu_sched_ctrlblk.rcucblist; + list = rcu_ctrlblk.rcucblist; + rcu_ctrlblk.rcucblist = *rcu_ctrlblk.donetail; + *rcu_ctrlblk.donetail = NULL; + if (rcu_ctrlblk.curtail == rcu_ctrlblk.donetail) + rcu_ctrlblk.curtail = &rcu_ctrlblk.rcucblist; + rcu_ctrlblk.donetail = &rcu_ctrlblk.rcucblist; local_irq_restore(flags); /* Invoke the callbacks on the local list. */ @@ -125,21 +125,21 @@ static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused * * Cool, huh? (Due to Josh Triplett.) */ -void synchronize_sched(void) +void synchronize_rcu(void) { RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || lock_is_held(&rcu_lock_map) || lock_is_held(&rcu_sched_lock_map), "Illegal synchronize_sched() in RCU read-side critical section"); } -EXPORT_SYMBOL_GPL(synchronize_sched); +EXPORT_SYMBOL_GPL(synchronize_rcu); /* * Post an RCU callback to be invoked after the end of an RCU-sched grace * period. But since we have but one CPU, that would be after any * quiescent state. */ -void call_rcu_sched(struct rcu_head *head, rcu_callback_t func) +void call_rcu(struct rcu_head *head, rcu_callback_t func) { unsigned long flags; @@ -148,16 +148,16 @@ void call_rcu_sched(struct rcu_head *head, rcu_callback_t func) head->next = NULL; local_irq_save(flags); - *rcu_sched_ctrlblk.curtail = head; - rcu_sched_ctrlblk.curtail = &head->next; + *rcu_ctrlblk.curtail = head; + rcu_ctrlblk.curtail = &head->next; local_irq_restore(flags); if (unlikely(is_idle_task(current))) { - /* force scheduling for rcu_sched_qs() */ + /* force scheduling for rcu_qs() */ resched_cpu(0); } } -EXPORT_SYMBOL_GPL(call_rcu_sched); +EXPORT_SYMBOL_GPL(call_rcu); void __init rcu_init(void) { -- 2.45.2