[PATCH tip/core/rcu 1/7] sched: Un-hide lockdep_tasklist_lock_is_held() for !LOCKDEP

From: paulmck
Date: Thu Nov 05 2020 - 18:24:58 EST


From: Jakub Kicinski <kuba@xxxxxxxxxx>

Currently, variables used only within lockdep expressions are flagged as
unused, requiring that these variables' declarations be decorated with
either #ifdef or __maybe_unused. This results in ugly code. This commit
therefore causes the lockdep_tasklist_lock_is_held() function to be
visible even when lockdep is not enabled, thus removing the need for
these decorations. This approach further relies on dead-code elimination
to remove any references to functions or variables that are not available
in non-lockdep kernels.

Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
include/linux/sched/task.h | 2 --
1 file changed, 2 deletions(-)

diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 85fb2f3..c0f71f2 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -47,9 +47,7 @@ extern spinlock_t mmlist_lock;
extern union thread_union init_thread_union;
extern struct task_struct init_task;

-#ifdef CONFIG_PROVE_RCU
extern int lockdep_tasklist_lock_is_held(void);
-#endif /* #ifdef CONFIG_PROVE_RCU */

extern asmlinkage void schedule_tail(struct task_struct *prev);
extern void init_idle(struct task_struct *idle, int cpu);
--
2.9.5