diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/init_task.h | 9 | ||||
| -rw-r--r-- | include/linux/rcupdate.h | 36 | ||||
| -rw-r--r-- | include/linux/sched.h | 23 |
3 files changed, 57 insertions, 11 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 2bb4c4f3531a..dffd9258ee60 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -117,6 +117,14 @@ extern struct group_info init_groups; #else #define INIT_TASK_RCU_PREEMPT(tsk) #endif +#ifdef CONFIG_TASKS_RCU +#define INIT_TASK_RCU_TASKS(tsk) \ + .rcu_tasks_holdout = false, \ + .rcu_tasks_holdout_list = \ + LIST_HEAD_INIT(tsk.rcu_tasks_holdout_list), +#else +#define INIT_TASK_RCU_TASKS(tsk) +#endif extern struct cred init_cred; @@ -224,6 +232,7 @@ extern struct task_group root_task_group; INIT_FTRACE_GRAPH \ INIT_TRACE_RECURSION \ INIT_TASK_RCU_PREEMPT(tsk) \ + INIT_TASK_RCU_TASKS(tsk) \ INIT_CPUSET_SEQ(tsk) \ INIT_RT_MUTEXES(tsk) \ INIT_VTIME(tsk) \ 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) */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 5c2c885ee52b..eaacac4ae77d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1270,6 +1270,11 @@ struct task_struct { #ifdef CONFIG_TREE_PREEMPT_RCU struct rcu_node *rcu_blocked_node; #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ +#ifdef CONFIG_TASKS_RCU + unsigned long rcu_tasks_nvcsw; + bool rcu_tasks_holdout; + struct list_head rcu_tasks_holdout_list; +#endif /* #ifdef CONFIG_TASKS_RCU */ #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) struct sched_info sched_info; @@ -2000,28 +2005,24 @@ extern void task_clear_jobctl_pending(struct task_struct *task, unsigned int mask); #ifdef CONFIG_PREEMPT_RCU - #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */ #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */ +#endif /* #ifdef CONFIG_PREEMPT_RCU */ static inline void rcu_copy_process(struct task_struct *p) { +#ifdef CONFIG_PREEMPT_RCU p->rcu_read_lock_nesting = 0; p->rcu_read_unlock_special = 0; -#ifdef CONFIG_TREE_PREEMPT_RCU p->rcu_blocked_node = NULL; -#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ INIT_LIST_HEAD(&p->rcu_node_entry); +#endif /* #ifdef CONFIG_PREEMPT_RCU */ +#ifdef CONFIG_TASKS_RCU + p->rcu_tasks_holdout = false; + INIT_LIST_HEAD(&p->rcu_tasks_holdout_list); +#endif /* #ifdef CONFIG_TASKS_RCU */ } -#else - -static inline void rcu_copy_process(struct task_struct *p) -{ -} - -#endif - static inline void tsk_restore_flags(struct task_struct *task, unsigned long orig_flags, unsigned long flags) { |