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편집 파일: rcutree.h

/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * * Copyright IBM Corporation, 2008 * * Author: Dipankar Sarma <dipankar@in.ibm.com> * Paul E. McKenney <paulmck@linux.ibm.com> Hierarchical algorithm * * Based on the original work by Paul McKenney <paulmck@linux.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 void rcu_softirq_qs(void); void rcu_note_context_switch(bool preempt); int rcu_needs_cpu(void); void rcu_cpu_stall_reset(void); void rcu_request_urgent_qs_task(struct task_struct *t); /* * 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. The caller must have disabled interrupts. */ static inline void rcu_virt_note_context_switch(void) { rcu_note_context_switch(false); } void synchronize_rcu_expedited(void); void kvfree_call_rcu(struct rcu_head *head, void *ptr); void rcu_barrier(void); bool rcu_eqs_special_set(int cpu); void rcu_momentary_dyntick_idle(void); void kfree_rcu_scheduler_running(void); bool rcu_gp_might_be_stalled(void); struct rcu_gp_oldstate { unsigned long rgos_norm; unsigned long rgos_exp; }; // Maximum number of rcu_gp_oldstate values corresponding to // not-yet-completed RCU grace periods. #define NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE 4 /** * same_state_synchronize_rcu_full - Are two old-state values identical? * @rgosp1: First old-state value. * @rgosp2: Second old-state value. * * The two old-state values must have been obtained from either * get_state_synchronize_rcu_full(), start_poll_synchronize_rcu_full(), * or get_completed_synchronize_rcu_full(). Returns @true if the two * values are identical and @false otherwise. This allows structures * whose lifetimes are tracked by old-state values to push these values * to a list header, allowing those structures to be slightly smaller. * * Note that equality is judged on a bitwise basis, so that an * @rcu_gp_oldstate structure with an already-completed state in one field * will compare not-equal to a structure with an already-completed state * in the other field. After all, the @rcu_gp_oldstate structure is opaque * so how did such a situation come to pass in the first place? */ static inline bool same_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp1, struct rcu_gp_oldstate *rgosp2) { return rgosp1->rgos_norm == rgosp2->rgos_norm && rgosp1->rgos_exp == rgosp2->rgos_exp; } unsigned long start_poll_synchronize_rcu_expedited(void); void start_poll_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp); void cond_synchronize_rcu_expedited(unsigned long oldstate); void cond_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp); unsigned long get_state_synchronize_rcu(void); void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); unsigned long start_poll_synchronize_rcu(void); void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); bool poll_state_synchronize_rcu(unsigned long oldstate); bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); void cond_synchronize_rcu(unsigned long oldstate); void cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); bool rcu_is_idle_cpu(int cpu); #ifdef CONFIG_PROVE_RCU void rcu_irq_exit_check_preempt(void); #else static inline void rcu_irq_exit_check_preempt(void) { } #endif struct task_struct; void rcu_preempt_deferred_qs(struct task_struct *t); void exit_rcu(void); void rcu_scheduler_starting(void); extern int rcu_scheduler_active; void rcu_end_inkernel_boot(void); bool rcu_inkernel_boot_has_ended(void); bool rcu_is_watching(void); #ifndef CONFIG_PREEMPTION void rcu_all_qs(void); #endif /* RCUtree hotplug events */ int rcutree_prepare_cpu(unsigned int cpu); int rcutree_online_cpu(unsigned int cpu); int rcutree_offline_cpu(unsigned int cpu); int rcutree_dead_cpu(unsigned int cpu); int rcutree_dying_cpu(unsigned int cpu); void rcu_cpu_starting(unsigned int cpu); #endif /* __LINUX_RCUTREE_H */