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53d84e004d
When using a kernel debugger, a long sojourn in the debugger can get you lots of RCU CPU stall warnings once you resume. This might not be helpful, especially if you are using the system console. This patch therefore allows RCU CPU stall warnings to be suppressed, but only for the duration of the current set of grace periods. This differs from Jason's original patch in that it adds support for tiny RCU and preemptible RCU, and uses a slightly different method for suppressing the RCU CPU stall warning messages. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Jason Wessel <jason.wessel@windriver.com>
131 lines
3.4 KiB
C
131 lines
3.4 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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struct notifier_block;
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extern void rcu_sched_qs(int cpu);
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extern void rcu_bh_qs(int cpu);
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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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#ifdef CONFIG_TREE_PREEMPT_RCU
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extern void __rcu_read_lock(void);
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extern void __rcu_read_unlock(void);
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extern void synchronize_rcu(void);
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extern void exit_rcu(void);
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/*
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* Defined as macro as it is a very low level header
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* included from areas that don't even know about current
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*/
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#define rcu_preempt_depth() (current->rcu_read_lock_nesting)
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#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
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static inline void __rcu_read_lock(void)
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{
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preempt_disable();
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}
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static inline void __rcu_read_unlock(void)
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{
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preempt_enable();
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}
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#define synchronize_rcu synchronize_sched
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static inline void exit_rcu(void)
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{
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}
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static inline int rcu_preempt_depth(void)
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{
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return 0;
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}
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#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
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static inline void __rcu_read_lock_bh(void)
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{
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local_bh_disable();
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}
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static inline void __rcu_read_unlock_bh(void)
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{
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local_bh_enable();
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}
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extern void call_rcu_sched(struct rcu_head *head,
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void (*func)(struct rcu_head *rcu));
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extern void synchronize_rcu_bh(void);
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extern void synchronize_sched(void);
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extern void synchronize_rcu_expedited(void);
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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_check_callbacks(int cpu, int user);
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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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#ifdef CONFIG_NO_HZ
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void rcu_enter_nohz(void);
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void rcu_exit_nohz(void);
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#else /* CONFIG_NO_HZ */
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static inline void rcu_enter_nohz(void)
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{
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}
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static inline void rcu_exit_nohz(void)
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{
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}
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#endif /* CONFIG_NO_HZ */
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/* A context switch is a grace period for RCU-sched and RCU-bh. */
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static inline int rcu_blocking_is_gp(void)
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{
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return num_online_cpus() == 1;
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}
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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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