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       1                 :            : /*
       2                 :            :  * Read-Copy Update mechanism for mutual exclusion (tree-based version)
       3                 :            :  *
       4                 :            :  * This program is free software; you can redistribute it and/or modify
       5                 :            :  * it under the terms of the GNU General Public License as published by
       6                 :            :  * the Free Software Foundation; either version 2 of the License, or
       7                 :            :  * (at your option) any later version.
       8                 :            :  *
       9                 :            :  * This program is distributed in the hope that it will be useful,
      10                 :            :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      11                 :            :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12                 :            :  * GNU General Public License for more details.
      13                 :            :  *
      14                 :            :  * You should have received a copy of the GNU General Public License
      15                 :            :  * along with this program; if not, write to the Free Software
      16                 :            :  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
      17                 :            :  *
      18                 :            :  * Copyright IBM Corporation, 2008
      19                 :            :  *
      20                 :            :  * Author: Dipankar Sarma <dipankar@in.ibm.com>
      21                 :            :  *         Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
      22                 :            :  *
      23                 :            :  * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
      24                 :            :  * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
      25                 :            :  *
      26                 :            :  * For detailed explanation of Read-Copy Update mechanism see -
      27                 :            :  *      Documentation/RCU
      28                 :            :  */
      29                 :            : 
      30                 :            : #ifndef __LINUX_RCUTREE_H
      31                 :            : #define __LINUX_RCUTREE_H
      32                 :            : 
      33                 :            : void rcu_note_context_switch(int cpu);
      34                 :            : int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
      35                 :            : void rcu_cpu_stall_reset(void);
      36                 :            : 
      37                 :            : /*
      38                 :            :  * Note a virtualization-based context switch.  This is simply a
      39                 :            :  * wrapper around rcu_note_context_switch(), which allows TINY_RCU
      40                 :            :  * to save a few bytes.
      41                 :            :  */
      42                 :            : static inline void rcu_virt_note_context_switch(int cpu)
      43                 :            : {
      44                 :            :         rcu_note_context_switch(cpu);
      45                 :            : }
      46                 :            : 
      47                 :            : void synchronize_rcu_bh(void);
      48                 :            : void synchronize_sched_expedited(void);
      49                 :            : void synchronize_rcu_expedited(void);
      50                 :            : 
      51                 :            : void kfree_call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
      52                 :            : 
      53                 :            : /**
      54                 :            :  * synchronize_rcu_bh_expedited - Brute-force RCU-bh grace period
      55                 :            :  *
      56                 :            :  * Wait for an RCU-bh grace period to elapse, but use a "big hammer"
      57                 :            :  * approach to force the grace period to end quickly.  This consumes
      58                 :            :  * significant time on all CPUs and is unfriendly to real-time workloads,
      59                 :            :  * so is thus not recommended for any sort of common-case code.  In fact,
      60                 :            :  * if you are using synchronize_rcu_bh_expedited() in a loop, please
      61                 :            :  * restructure your code to batch your updates, and then use a single
      62                 :            :  * synchronize_rcu_bh() instead.
      63                 :            :  *
      64                 :            :  * Note that it is illegal to call this function while holding any lock
      65                 :            :  * that is acquired by a CPU-hotplug notifier.  And yes, it is also illegal
      66                 :            :  * to call this function from a CPU-hotplug notifier.  Failing to observe
      67                 :            :  * these restriction will result in deadlock.
      68                 :            :  */
      69                 :            : static inline void synchronize_rcu_bh_expedited(void)
      70                 :            : {
      71                 :          0 :         synchronize_sched_expedited();
      72                 :            : }
      73                 :            : 
      74                 :            : void rcu_barrier(void);
      75                 :            : void rcu_barrier_bh(void);
      76                 :            : void rcu_barrier_sched(void);
      77                 :            : 
      78                 :            : extern unsigned long rcutorture_testseq;
      79                 :            : extern unsigned long rcutorture_vernum;
      80                 :            : long rcu_batches_completed(void);
      81                 :            : long rcu_batches_completed_bh(void);
      82                 :            : long rcu_batches_completed_sched(void);
      83                 :            : 
      84                 :            : void rcu_force_quiescent_state(void);
      85                 :            : void rcu_bh_force_quiescent_state(void);
      86                 :            : void rcu_sched_force_quiescent_state(void);
      87                 :            : 
      88                 :            : void exit_rcu(void);
      89                 :            : 
      90                 :            : void rcu_scheduler_starting(void);
      91                 :            : extern int rcu_scheduler_active __read_mostly;
      92                 :            : 
      93                 :            : bool rcu_is_watching(void);
      94                 :            : 
      95                 :            : #endif /* __LINUX_RCUTREE_H */