From: Arnd Bergmann <arnd@xxxxxxxx>
Both the CONFIG_TASKS_RCU and CONFIG_TASKS_RUDE_RCU options
are broken when RCU_TINY is enabled as well, as some functions
are missing a declaration.
In file included from kernel/rcu/update.c:649:
kernel/rcu/tasks.h:1271:21: error: no previous prototype for 'get_rcu_tasks_rude_gp_kthread' [-Werror=missing-prototypes]
1271 | struct task_struct *get_rcu_tasks_rude_gp_kthread(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/rcu/rcuscale.c:330:27: error: 'get_rcu_tasks_rude_gp_kthread' undeclared here (not in a function); did you mean 'get_rcu_tasks_trace_gp_kthread'?
330 | .rso_gp_kthread = get_rcu_tasks_rude_gp_kthread,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| get_rcu_tasks_trace_gp_kthread
In file included from /home/arnd/arm-soc/kernel/rcu/update.c:649:
kernel/rcu/tasks.h:1113:21: error: no previous prototype for 'get_rcu_tasks_gp_kthread' [-Werror=missing-prototypes]
1113 | struct task_struct *get_rcu_tasks_gp_kthread(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~
Also, building with CONFIG_TASKS_RUDE_RCU but not CONFIG_TASKS_RCU is
broken because of some missing stub functions:
kernel/rcu/rcuscale.c:322:27: error: 'tasks_scale_read_lock' undeclared here (not in a function); did you mean 'srcu_scale_read_lock'?
322 | .readlock = tasks_scale_read_lock,
| ^~~~~~~~~~~~~~~~~~~~~
| srcu_scale_read_lock
kernel/rcu/rcuscale.c:323:27: error: 'tasks_scale_read_unlock' undeclared here (not in a function); did you mean 'srcu_scale_read_unlock'?
323 | .readunlock = tasks_scale_read_unlock,
| ^~~~~~~~~~~~~~~~~~~~~~~
| srcu_scale_read_unlock
Move the declarations outside of the RCU_TINY #ifdef and duplicate the
shared stub functions to address all of the above.
Fixes: 88d7ff818f0ce ("rcuscale: Add RCU Tasks Rude testing")
Fixes: 755f1c5eb416b ("rcuscale: Measure RCU Tasks Trace grace-period kthread CPU time")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/rcu.h | 14 ++++++++------
kernel/rcu/rcuscale.c | 13 +++++++++++--
2 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 9829d8161b21..5befd8780dcd 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -505,18 +505,20 @@ 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
-# ifdef CONFIG_TASKS_RUDE_RCU
-struct task_struct *get_rcu_tasks_rude_gp_kthread(void);
-# endif // # ifdef CONFIG_TASKS_RUDE_RCU
#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
static inline void show_rcu_tasks_gp_kthreads(void) {}
#endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
void rcu_request_urgent_qs_task(struct task_struct *t);
#endif /* #else #ifdef CONFIG_TINY_RCU */
+#ifdef CONFIG_TASKS_RCU
+struct task_struct *get_rcu_tasks_gp_kthread(void);
+#endif // # ifdef CONFIG_TASKS_RCU
+
+#ifdef CONFIG_TASKS_RUDE_RCU
+struct task_struct *get_rcu_tasks_rude_gp_kthread(void);
+#endif // # ifdef CONFIG_TASKS_RUDE_RCU
+
#define RCU_SCHEDULER_INACTIVE 0
#define RCU_SCHEDULER_INIT 1
#define RCU_SCHEDULER_RUNNING 2
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 5ce3b4e7ce71..a0eae1900708 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -316,11 +316,20 @@ static struct rcu_scale_ops tasks_ops = {
* Definitions for RCU-tasks-rude scalability testing.
*/
+static int tasks_rude_scale_read_lock(void)
+{
+ return 0;
+}
+
+static void tasks_rude_scale_read_unlock(int idx)
+{
+}
+
static struct rcu_scale_ops tasks_rude_ops = {
.ptype = RCU_TASKS_RUDE_FLAVOR,
.init = rcu_sync_scale_init,
- .readlock = tasks_scale_read_lock,
- .readunlock = tasks_scale_read_unlock,
+ .readlock = tasks_rude_scale_read_lock,
+ .readunlock = tasks_rude_scale_read_unlock,
.get_gp_seq = rcu_no_completed,
.gp_diff = rcu_seq_diff,
.async = call_rcu_tasks_rude,
--
2.40.1
