rcu-tasks: Add RCU tasks to rcutorture writer stall output

This commit adds state for each RCU-tasks flavor to the rcutorture
writer stall output.  The initial state is minimal, but you have to
start somewhere.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ paulmck: Fixes based on feedback from kbuild test robot. ]

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 72903867833e6ba9e2bdde1bf64b5f6d59541cd3..e1089fdf8626d4ba7858225c39904457e3993449 100644 (file)
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -431,6 +431,7 @@ bool rcu_gp_is_expedited(void);  /* Internal RCU use. */
 void rcu_expedite_gp(void);
 void rcu_unexpedite_gp(void);
 void rcupdate_announce_bootup_oddness(void);
+void show_rcu_tasks_gp_kthreads(void);
 void rcu_request_urgent_qs_task(struct task_struct *t);
 #endif /* #else #ifdef CONFIG_TINY_RCU */
 

diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index b7e3e1d28a5ccc1565195ce1405cfa96f78d565b..e4f89425d2c41d6ec2a8482083843c9a17ab2eee 100644 (file)
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -219,6 +219,16 @@ static void __init rcu_tasks_bootup_oddness(void)
 
 #endif /* #ifndef CONFIG_TINY_RCU */
 
+/* Dump out rcutorture-relevant state common to all RCU-tasks flavors. */
+static void show_rcu_tasks_generic_gp_kthread(struct rcu_tasks *rtp, char *s)
+{
+       pr_info("%s %c%c %s\n",
+               rtp->kname,
+               ".k"[!!data_race(rtp->kthread_ptr)],
+               ".C"[!!data_race(rtp->cbs_head)],
+               s);
+}
+
 #ifdef CONFIG_TASKS_RCU
 
 ////////////////////////////////////////////////////////////////////////
@@ -482,7 +492,14 @@ static int __init rcu_spawn_tasks_kthread(void)
 }
 core_initcall(rcu_spawn_tasks_kthread);
 
-#endif /* #ifdef CONFIG_TASKS_RCU */
+static void show_rcu_tasks_classic_gp_kthread(void)
+{
+       show_rcu_tasks_generic_gp_kthread(&rcu_tasks, "");
+}
+
+#else /* #ifdef CONFIG_TASKS_RCU */
+static void show_rcu_tasks_classic_gp_kthread(void) { }
+#endif /* #else #ifdef CONFIG_TASKS_RCU */
 
 #ifdef CONFIG_TASKS_RUDE_RCU
 
@@ -578,7 +595,14 @@ static int __init rcu_spawn_tasks_rude_kthread(void)
 }
 core_initcall(rcu_spawn_tasks_rude_kthread);
 
-#endif /* #ifdef CONFIG_TASKS_RUDE_RCU */
+static void show_rcu_tasks_rude_gp_kthread(void)
+{
+       show_rcu_tasks_generic_gp_kthread(&rcu_tasks_rude, "");
+}
+
+#else /* #ifdef CONFIG_TASKS_RUDE_RCU */
+static void show_rcu_tasks_rude_gp_kthread(void) {}
+#endif /* #else #ifdef CONFIG_TASKS_RUDE_RCU */
 
 ////////////////////////////////////////////////////////////////////////
 //
@@ -982,10 +1006,27 @@ static int __init rcu_spawn_tasks_trace_kthread(void)
 }
 core_initcall(rcu_spawn_tasks_trace_kthread);
 
+static void show_rcu_tasks_trace_gp_kthread(void)
+{
+       char buf[32];
+
+       sprintf(buf, "N%d", atomic_read(&trc_n_readers_need_end));
+       show_rcu_tasks_generic_gp_kthread(&rcu_tasks_trace, buf);
+}
+
 #else /* #ifdef CONFIG_TASKS_TRACE_RCU */
 void exit_tasks_rcu_finish_trace(struct task_struct *t) { }
+static inline void show_rcu_tasks_trace_gp_kthread(void) {}
 #endif /* #else #ifdef CONFIG_TASKS_TRACE_RCU */
 
+void show_rcu_tasks_gp_kthreads(void)
+{
+       show_rcu_tasks_classic_gp_kthread();
+       show_rcu_tasks_rude_gp_kthread();
+       show_rcu_tasks_trace_gp_kthread();
+}
+
 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
 static inline void rcu_tasks_bootup_oddness(void) {}
+void show_rcu_tasks_gp_kthreads(void) {}
 #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */

diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index c65c9759e0384b67a5a455b52084c4b65fa91fb2..e1c68a74574f7ad3a22bc4786d7264aace2021a9 100644 (file)
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -649,7 +649,7 @@ void show_rcu_gp_kthreads(void)
                if (rcu_segcblist_is_offloaded(&rdp->cblist))
                        show_rcu_nocb_state(rdp);
        }
-       /* sched_show_task(rcu_state.gp_kthread); */
+       show_rcu_tasks_gp_kthreads();
 }
 EXPORT_SYMBOL_GPL(show_rcu_gp_kthreads);