This commit causes RCU Tasks Trace to output the CPU time consumed by
its grace-period kthread. The CPU time is whatever is in the designated
task's current->stime field, and thus is controlled by whatever CPU-time
accounting scheme is in effect.
This output appears in microseconds as follows on the console:
rcu_scale: Grace-period kthread CPU time: 42367.037
[ paulmck: Apply Willy Tarreau feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/rcu.h | 3 +++
kernel/rcu/rcuscale.c | 1 +
kernel/rcu/tasks.h | 6 ++++++
3 files changed, 10 insertions(+)
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 98c1544cf572..d58bc0e86769 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -505,6 +505,9 @@ void rcu_async_relax(void);
void rcupdate_announce_bootup_oddness(void);
#ifdef CONFIG_TASKS_RCU_GENERIC
void show_rcu_tasks_gp_kthreads(void);
+# ifdef CONFIG_TASKS_RCU
+struct task_struct *get_rcu_tasks_gp_kthread(void);
+# endif // # ifdef CONFIG_TASKS_RCU
#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
static inline void show_rcu_tasks_gp_kthreads(void) {}
#endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 7fba3ab66e35..35e06c86acc9 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -298,6 +298,7 @@ static struct rcu_scale_ops tasks_ops = {
.gp_barrier = rcu_barrier_tasks,
.sync = synchronize_rcu_tasks,
.exp_sync = synchronize_rcu_tasks,
+ .rso_gp_kthread = get_rcu_tasks_gp_kthread,
.name = "tasks"
};
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 990a6cf5fa35..0f03de023097 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -1042,6 +1042,12 @@ void show_rcu_tasks_classic_gp_kthread(void)
EXPORT_SYMBOL_GPL(show_rcu_tasks_classic_gp_kthread);
#endif // !defined(CONFIG_TINY_RCU)
+struct task_struct *get_rcu_tasks_gp_kthread(void)
+{
+ return rcu_tasks.kthread_ptr;
+}
+EXPORT_SYMBOL_GPL(get_rcu_tasks_gp_kthread);
+
/*
* Contribute to protect against tasklist scan blind spot while the
* task is exiting and may be removed from the tasklist. See
--
2.40.1
