diff options
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index d231aa17b1d7..3432063f4c87 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -197,6 +197,26 @@ void call_rcu_sched(struct rcu_head *head, void synchronize_sched(void); +/** + * call_rcu_tasks() - Queue an RCU for invocation task-based grace period + * @head: structure to be used for queueing the RCU updates. + * @func: actual callback function to be invoked after the grace period + * + * The callback function will be invoked some time after a full grace + * period elapses, in other words after all currently executing RCU + * read-side critical sections have completed. call_rcu_tasks() assumes + * that the read-side critical sections end at a voluntary context + * switch (not a preemption!), entry into idle, or transition to usermode + * execution. As such, there are no read-side primitives analogous to + * rcu_read_lock() and rcu_read_unlock() because this primitive is intended + * to determine that all tasks have passed through a safe state, not so + * much for data-strcuture synchronization. + * + * See the description of call_rcu() for more detailed information on + * memory ordering guarantees. + */ +void call_rcu_tasks(struct rcu_head *head, void (*func)(struct rcu_head *head)); + #ifdef CONFIG_PREEMPT_RCU void __rcu_read_lock(void); @@ -294,6 +314,22 @@ static inline void rcu_user_hooks_switch(struct task_struct *prev, rcu_irq_exit(); \ } while (0) +/* + * Note a voluntary context switch for RCU-tasks benefit. This is a + * macro rather than an inline function to avoid #include hell. + */ +#ifdef CONFIG_TASKS_RCU +#define rcu_note_voluntary_context_switch(t) \ + do { \ + preempt_disable(); /* Exclude synchronize_sched(); */ \ + if (ACCESS_ONCE((t)->rcu_tasks_holdout)) \ + ACCESS_ONCE((t)->rcu_tasks_holdout) = false; \ + preempt_enable(); \ + } while (0) +#else /* #ifdef CONFIG_TASKS_RCU */ +#define rcu_note_voluntary_context_switch(t) do { } while (0) +#endif /* #else #ifdef CONFIG_TASKS_RCU */ + #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) || defined(CONFIG_SMP) bool __rcu_is_watching(void); #endif /* #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) || defined(CONFIG_SMP) */ |