{
pid_t ppid;
+
+ /*
+ * TODO: when we eventually add RCU subsystem instrumentation,
+ * taking the rcu read lock here will trigger RCU tracing
+ * recursively. We should modify the kernel synchronization so
+ * it synchronizes both for RCU and RCU sched, and rely on
+ * rcu_read_lock_sched_notrace.
+ */
+
rcu_read_lock();
ppid = task_tgid_nr(current->real_parent);
rcu_read_unlock();