mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 00:40:03 +00:00
![Paul E. McKenney](/assets/img/avatar_default.png)
This commit replaces a local_irq_save()/local_irq_restore() pair with a lockdep assertion that interrupts are already disabled. This should remove the corresponding overhead from the interrupt entry/exit fastpaths. This change was inspired by the fact that Iftekhar Ahmed's mutation testing showed that removing rcu_irq_enter()'s call to local_ird_restore() had no effect, which might indicate that interrupts were always enabled anyway. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
112 lines
3.7 KiB
C
112 lines
3.7 KiB
C
/*
|
|
* 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, you can access it online at
|
|
* http://www.gnu.org/licenses/gpl-2.0.html.
|
|
*
|
|
* 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
|
|
|
|
void rcu_note_context_switch(void);
|
|
int rcu_needs_cpu(u64 basem, u64 *nextevt);
|
|
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. The caller must have disabled interrupts.
|
|
*/
|
|
static inline void rcu_virt_note_context_switch(int cpu)
|
|
{
|
|
rcu_note_context_switch();
|
|
}
|
|
|
|
void synchronize_rcu_bh(void);
|
|
void synchronize_sched_expedited(void);
|
|
void synchronize_rcu_expedited(void);
|
|
|
|
void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func);
|
|
|
|
/**
|
|
* 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();
|
|
}
|
|
|
|
void rcu_barrier(void);
|
|
void rcu_barrier_bh(void);
|
|
void rcu_barrier_sched(void);
|
|
unsigned long get_state_synchronize_rcu(void);
|
|
void cond_synchronize_rcu(unsigned long oldstate);
|
|
unsigned long get_state_synchronize_sched(void);
|
|
void cond_synchronize_sched(unsigned long oldstate);
|
|
|
|
extern unsigned long rcutorture_testseq;
|
|
extern unsigned long rcutorture_vernum;
|
|
unsigned long rcu_batches_started(void);
|
|
unsigned long rcu_batches_started_bh(void);
|
|
unsigned long rcu_batches_started_sched(void);
|
|
unsigned long rcu_batches_completed(void);
|
|
unsigned long rcu_batches_completed_bh(void);
|
|
unsigned long rcu_batches_completed_sched(void);
|
|
void show_rcu_gp_kthreads(void);
|
|
|
|
void rcu_force_quiescent_state(void);
|
|
void rcu_bh_force_quiescent_state(void);
|
|
void rcu_sched_force_quiescent_state(void);
|
|
|
|
void rcu_idle_enter(void);
|
|
void rcu_idle_exit(void);
|
|
void rcu_irq_enter(void);
|
|
void rcu_irq_exit(void);
|
|
void rcu_irq_enter_irqson(void);
|
|
void rcu_irq_exit_irqson(void);
|
|
|
|
void exit_rcu(void);
|
|
|
|
void rcu_scheduler_starting(void);
|
|
extern int rcu_scheduler_active __read_mostly;
|
|
|
|
bool rcu_is_watching(void);
|
|
|
|
void rcu_all_qs(void);
|
|
|
|
#endif /* __LINUX_RCUTREE_H */
|