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Diffstat (limited to 'include/linux/rcutree.h')
| -rw-r--r-- | include/linux/rcutree.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h new file mode 100644 index 00000000..e8ee5dd0 --- /dev/null +++ b/include/linux/rcutree.h @@ -0,0 +1,111 @@ +/* + * Read-Copy Update mechanism for mutual exclusion (tree-based version) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright IBM Corporation, 2008 + * + * Author: Dipankar Sarma <dipankar@in.ibm.com> + * Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm + * + * Based on the original work by Paul McKenney <paulmck@us.ibm.com> + * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. + * + * For detailed explanation of Read-Copy Update mechanism see - + * Documentation/RCU + */ + +#ifndef __LINUX_RCUTREE_H +#define __LINUX_RCUTREE_H + +extern void rcu_init(void); +extern void rcu_note_context_switch(int cpu); +extern int rcu_needs_cpu(int cpu); +extern void rcu_cpu_stall_reset(void); + +/* + * Note a virtualization-based context switch. This is simply a + * wrapper around rcu_note_context_switch(), which allows TINY_RCU + * to save a few bytes. + */ +static inline void rcu_virt_note_context_switch(int cpu) +{ + rcu_note_context_switch(cpu); +} + +#ifdef CONFIG_TREE_PREEMPT_RCU + +extern void exit_rcu(void); + +#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */ + +static inline void exit_rcu(void) +{ +} + +#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */ + +extern void synchronize_rcu_bh(void); +extern void synchronize_sched_expedited(void); +extern void synchronize_rcu_expedited(void); + +void kfree_call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu)); + +/** + * synchronize_rcu_bh_expedited - Brute-force RCU-bh grace period + * + * Wait for an RCU-bh grace period to elapse, but use a "big hammer" + * approach to force the grace period to end quickly. This consumes + * significant time on all CPUs and is unfriendly to real-time workloads, + * so is thus not recommended for any sort of common-case code. In fact, + * if you are using synchronize_rcu_bh_expedited() in a loop, please + * restructure your code to batch your updates, and then use a single + * synchronize_rcu_bh() instead. + * + * Note that it is illegal to call this function while holding any lock + * that is acquired by a CPU-hotplug notifier. And yes, it is also illegal + * to call this function from a CPU-hotplug notifier. Failing to observe + * these restriction will result in deadlock. + */ +static inline void synchronize_rcu_bh_expedited(void) +{ + synchronize_sched_expedited(); +} + +extern void rcu_barrier(void); +extern void rcu_barrier_bh(void); +extern void rcu_barrier_sched(void); + +extern unsigned long rcutorture_testseq; +extern unsigned long rcutorture_vernum; +extern long rcu_batches_completed(void); +extern long rcu_batches_completed_bh(void); +extern long rcu_batches_completed_sched(void); + +extern void rcu_force_quiescent_state(void); +extern void rcu_bh_force_quiescent_state(void); +extern void rcu_sched_force_quiescent_state(void); + +/* A context switch is a grace period for RCU-sched and RCU-bh. */ +static inline int rcu_blocking_is_gp(void) +{ + might_sleep(); /* Check for RCU read-side critical section. */ + return num_online_cpus() == 1; +} + +extern void rcu_scheduler_starting(void); +extern int rcu_scheduler_active __read_mostly; + +#endif /* __LINUX_RCUTREE_H */ |