diff options
| -rw-r--r-- | include/linux/rcupdate.h | 1 | ||||
| -rw-r--r-- | kernel/rcu/update.c | 7 |
2 files changed, 6 insertions, 2 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index a8af79738a0e..3bc5de08c0b7 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -45,6 +45,7 @@ #include <linux/bug.h> #include <linux/compiler.h> #include <linux/ktime.h> +#include <linux/irqflags.h> #include <asm/barrier.h> diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 3e888cd5a594..f0d8322bc3ec 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -528,6 +528,7 @@ static int rcu_task_stall_timeout __read_mostly = HZ * 60 * 10; module_param(rcu_task_stall_timeout, int, 0644); static void rcu_spawn_tasks_kthread(void); +static struct task_struct *rcu_tasks_kthread_ptr; /* * Post an RCU-tasks callback. First call must be from process context @@ -537,6 +538,7 @@ void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func) { unsigned long flags; bool needwake; + bool havetask = READ_ONCE(rcu_tasks_kthread_ptr); rhp->next = NULL; rhp->func = func; @@ -545,7 +547,9 @@ void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func) *rcu_tasks_cbs_tail = rhp; rcu_tasks_cbs_tail = &rhp->next; raw_spin_unlock_irqrestore(&rcu_tasks_cbs_lock, flags); - if (needwake) { + /* We can't create the thread unless interrupts are enabled. */ + if ((needwake && havetask) || + (!havetask && !irqs_disabled_flags(flags))) { rcu_spawn_tasks_kthread(); wake_up(&rcu_tasks_cbs_wq); } @@ -790,7 +794,6 @@ static int __noreturn rcu_tasks_kthread(void *arg) static void rcu_spawn_tasks_kthread(void) { static DEFINE_MUTEX(rcu_tasks_kthread_mutex); - static struct task_struct *rcu_tasks_kthread_ptr; struct task_struct *t; if (READ_ONCE(rcu_tasks_kthread_ptr)) { |