diff options
Diffstat (limited to 'kernel/rcu/update.c')
| -rw-r--r-- | kernel/rcu/update.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index aef8109152ce..bad7dbd4c2e3 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -371,7 +371,7 @@ static DEFINE_RAW_SPINLOCK(rcu_tasks_cbs_lock); DEFINE_SRCU(tasks_rcu_exit_srcu); /* Control stall timeouts. Disable with <= 0, otherwise jiffies till stall. */ -static int rcu_task_stall_timeout __read_mostly = HZ * 60 * 3; +static int rcu_task_stall_timeout __read_mostly = HZ * 60 * 10; module_param(rcu_task_stall_timeout, int, 0644); /* Post an RCU-tasks callback. */ @@ -445,8 +445,9 @@ void rcu_barrier_tasks(void) } EXPORT_SYMBOL_GPL(rcu_barrier_tasks); -/* See if the current task has stopped holding out, remove from list if so. */ -static void check_holdout_task(struct task_struct *t) +/* See if tasks are still holding out, complain if so. */ +static void check_holdout_task(struct task_struct *t, + bool needreport, bool *firstreport) { if (!ACCESS_ONCE(t->rcu_tasks_holdout) || t->rcu_tasks_nvcsw != ACCESS_ONCE(t->nvcsw) || @@ -454,7 +455,15 @@ static void check_holdout_task(struct task_struct *t) ACCESS_ONCE(t->rcu_tasks_holdout) = false; list_del_rcu(&t->rcu_tasks_holdout_list); put_task_struct(t); + return; } + if (!needreport) + return; + if (*firstreport) { + pr_err("INFO: rcu_tasks detected stalls on tasks:\n"); + *firstreport = false; + } + sched_show_task(t); } /* RCU-tasks kthread that detects grace periods and invokes callbacks. */ @@ -462,6 +471,7 @@ static int __noreturn rcu_tasks_kthread(void *arg) { unsigned long flags; struct task_struct *g, *t; + unsigned long lastreport; struct rcu_head *list; struct rcu_head *next; LIST_HEAD(rcu_tasks_holdouts); @@ -540,13 +550,24 @@ static int __noreturn rcu_tasks_kthread(void *arg) * of holdout tasks, removing any that are no longer * holdouts. When the list is empty, we are done. */ + lastreport = jiffies; while (!list_empty(&rcu_tasks_holdouts)) { + bool firstreport; + bool needreport; + int rtst; + schedule_timeout_interruptible(HZ); + rtst = ACCESS_ONCE(rcu_task_stall_timeout); + needreport = rtst > 0 && + time_after(jiffies, lastreport + rtst); + if (needreport) + lastreport = jiffies; + firstreport = true; WARN_ON(signal_pending(current)); rcu_read_lock(); list_for_each_entry_rcu(t, &rcu_tasks_holdouts, rcu_tasks_holdout_list) - check_holdout_task(t); + check_holdout_task(t, needreport, &firstreport); rcu_read_unlock(); } |