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dc36be4419
barrier: Reduce the amount of disturbance by rcu_barrier() to the rest of
the system. This branch also includes improvements to
RCU_FAST_NO_HZ, which are included here due to conflicts.
fixes: Miscellaneous fixes.
inline: Remaining changes from an abortive attempt to inline
preemptible RCU's __rcu_read_lock(). These are (1) making
exit_rcu() avoid unnecessary work and (2) avoiding having
preemptible RCU record a blocked thread when the scheduler
declines to do a context switch.
srcu: Lai Jiangshan's algorithmic implementation of SRCU, including
call_srcu().
93 lines
3.3 KiB
C
93 lines
3.3 KiB
C
/*
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* Read-Copy Update mechanism for mutual exclusion (tree-based version)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright IBM Corporation, 2008
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*
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* Author: Dipankar Sarma <dipankar@in.ibm.com>
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* Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
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*
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* Based on the original work by Paul McKenney <paulmck@us.ibm.com>
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* and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
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*
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* For detailed explanation of Read-Copy Update mechanism see -
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* Documentation/RCU
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*/
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#ifndef __LINUX_RCUTREE_H
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#define __LINUX_RCUTREE_H
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extern void rcu_init(void);
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extern void rcu_note_context_switch(int cpu);
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extern int rcu_needs_cpu(int cpu);
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extern void rcu_cpu_stall_reset(void);
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/*
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* Note a virtualization-based context switch. This is simply a
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* wrapper around rcu_note_context_switch(), which allows TINY_RCU
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* to save a few bytes.
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*/
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static inline void rcu_virt_note_context_switch(int cpu)
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{
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rcu_note_context_switch(cpu);
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}
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extern void synchronize_rcu_bh(void);
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extern void synchronize_sched_expedited(void);
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extern void synchronize_rcu_expedited(void);
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void kfree_call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
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/**
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* synchronize_rcu_bh_expedited - Brute-force RCU-bh grace period
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*
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* Wait for an RCU-bh grace period to elapse, but use a "big hammer"
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* approach to force the grace period to end quickly. This consumes
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* significant time on all CPUs and is unfriendly to real-time workloads,
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* so is thus not recommended for any sort of common-case code. In fact,
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* if you are using synchronize_rcu_bh_expedited() in a loop, please
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* restructure your code to batch your updates, and then use a single
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* synchronize_rcu_bh() instead.
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*
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* Note that it is illegal to call this function while holding any lock
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* that is acquired by a CPU-hotplug notifier. And yes, it is also illegal
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* to call this function from a CPU-hotplug notifier. Failing to observe
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* these restriction will result in deadlock.
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*/
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static inline void synchronize_rcu_bh_expedited(void)
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{
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synchronize_sched_expedited();
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}
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extern void rcu_barrier(void);
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extern void rcu_barrier_bh(void);
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extern void rcu_barrier_sched(void);
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extern unsigned long rcutorture_testseq;
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extern unsigned long rcutorture_vernum;
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extern long rcu_batches_completed(void);
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extern long rcu_batches_completed_bh(void);
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extern long rcu_batches_completed_sched(void);
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extern void rcu_force_quiescent_state(void);
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extern void rcu_bh_force_quiescent_state(void);
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extern void rcu_sched_force_quiescent_state(void);
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extern void rcu_scheduler_starting(void);
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extern int rcu_scheduler_active __read_mostly;
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#endif /* __LINUX_RCUTREE_H */
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