diff options
| -rw-r--r-- | include/linux/init_task.h | 3 | ||||
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 2 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 2 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 16 | ||||
| -rw-r--r-- | kernel/rcu/update.c | 4 |
6 files changed, 27 insertions, 2 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h index dffd9258ee60..03b274873b06 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -121,7 +121,8 @@ extern struct group_info init_groups; #define INIT_TASK_RCU_TASKS(tsk) \ .rcu_tasks_holdout = false, \ .rcu_tasks_holdout_list = \ - LIST_HEAD_INIT(tsk.rcu_tasks_holdout_list), + LIST_HEAD_INIT(tsk.rcu_tasks_holdout_list), \ + .rcu_tasks_idle_cpu = -1, #else #define INIT_TASK_RCU_TASKS(tsk) #endif diff --git a/include/linux/sched.h b/include/linux/sched.h index eaacac4ae77d..ec8b34722bcc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1274,6 +1274,7 @@ struct task_struct { unsigned long rcu_tasks_nvcsw; bool rcu_tasks_holdout; struct list_head rcu_tasks_holdout_list; + int rcu_tasks_idle_cpu; #endif /* #ifdef CONFIG_TASKS_RCU */ #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) @@ -2020,6 +2021,7 @@ static inline void rcu_copy_process(struct task_struct *p) #ifdef CONFIG_TASKS_RCU p->rcu_tasks_holdout = false; INIT_LIST_HEAD(&p->rcu_tasks_holdout_list); + p->rcu_tasks_idle_cpu = -1; #endif /* #ifdef CONFIG_TASKS_RCU */ } diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e23dad0661e2..c880f5387b1f 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -526,6 +526,7 @@ static void rcu_eqs_enter_common(struct rcu_dynticks *rdtp, long long oldval, atomic_inc(&rdtp->dynticks); smp_mb__after_atomic(); /* Force ordering with next sojourn. */ WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1); + rcu_dynticks_task_enter(); /* * It is illegal to enter an extended quiescent state while @@ -642,6 +643,7 @@ void rcu_irq_exit(void) static void rcu_eqs_exit_common(struct rcu_dynticks *rdtp, long long oldval, int user) { + rcu_dynticks_task_exit(); smp_mb__before_atomic(); /* Force ordering w/previous sojourn. */ atomic_inc(&rdtp->dynticks); /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */ diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 6a86eb7bac45..3a92000c354f 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -605,6 +605,8 @@ static void rcu_sysidle_report_gp(struct rcu_state *rsp, int isidle, static void rcu_bind_gp_kthread(void); static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp); static bool rcu_nohz_full_cpu(struct rcu_state *rsp); +static void rcu_dynticks_task_enter(void); +static void rcu_dynticks_task_exit(void); #endif /* #ifndef RCU_TREE_NONCORE */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 7672586d3920..e466b40052a7 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -3036,3 +3036,19 @@ static void rcu_bind_gp_kthread(void) housekeeping_affine(current); #endif /* #else #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */ } + +/* Record the current task on dyntick-idle entry. */ +static void rcu_dynticks_task_enter(void) +{ +#if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL) + ACCESS_ONCE(current->rcu_tasks_idle_cpu) = smp_processor_id(); +#endif /* #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL) */ +} + +/* Record no current task on dyntick-idle exit. */ +static void rcu_dynticks_task_exit(void) +{ +#if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL) + ACCESS_ONCE(current->rcu_tasks_idle_cpu) = -1; +#endif /* #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL) */ +} diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index e1d71741958f..2658de4a5975 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -463,7 +463,9 @@ static void check_holdout_task(struct task_struct *t, { if (!ACCESS_ONCE(t->rcu_tasks_holdout) || t->rcu_tasks_nvcsw != ACCESS_ONCE(t->nvcsw) || - !ACCESS_ONCE(t->on_rq)) { + !ACCESS_ONCE(t->on_rq) || + (IS_ENABLED(CONFIG_NO_HZ_FULL) && + !is_idle_task(t) && t->rcu_tasks_idle_cpu >= 0)) { ACCESS_ONCE(t->rcu_tasks_holdout) = false; list_del_rcu(&t->rcu_tasks_holdout_list); put_task_struct(t); |