rcu: Move rcu_print_task_exp_stall() to tree_exp.h
Because expedited CPU stall warnings are contained within the
kernel/rcu/tree_exp.h file, rcu_print_task_exp_stall() should live
there too. This commit carries out the required code motion.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 4c2a018..7be3e08 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -10,6 +10,7 @@
#include <linux/lockdep.h>
static void rcu_exp_handler(void *unused);
+static int rcu_print_task_exp_stall(struct rcu_node *rnp);
/*
* Record the start of an expedited grace period.
@@ -670,6 +671,27 @@ static void sync_sched_exp_online_cleanup(int cpu)
{
}
+/*
+ * Scan the current list of tasks blocked within RCU read-side critical
+ * sections, printing out the tid of each that is blocking the current
+ * expedited grace period.
+ */
+static int rcu_print_task_exp_stall(struct rcu_node *rnp)
+{
+ struct task_struct *t;
+ int ndetected = 0;
+
+ if (!rnp->exp_tasks)
+ return 0;
+ t = list_entry(rnp->exp_tasks->prev,
+ struct task_struct, rcu_node_entry);
+ list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) {
+ pr_cont(" P%d", t->pid);
+ ndetected++;
+ }
+ return ndetected;
+}
+
#else /* #ifdef CONFIG_PREEMPT_RCU */
/* Invoked on each online non-idle CPU for expedited quiescent state. */
@@ -709,6 +731,16 @@ static void sync_sched_exp_online_cleanup(int cpu)
WARN_ON_ONCE(ret);
}
+/*
+ * Because preemptible RCU does not exist, we never have to check for
+ * tasks blocked within RCU read-side critical sections that are
+ * blocking the current expedited grace period.
+ */
+static int rcu_print_task_exp_stall(struct rcu_node *rnp)
+{
+ return 0;
+}
+
#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
/**