rcu-tasks: Convert RCU_LOCKDEP_WARN() to WARN_ONCE()

[ Upstream commit fcd53c8a4dfa38bafb89efdd0b0f718f3a03f884 ]

Kernels built with CONFIG_PROVE_RCU=y and CONFIG_DEBUG_LOCK_ALLOC=y
attempt to emit a warning when the synchronize_rcu_tasks_generic()
function is called during early boot while the rcu_scheduler_active
variable is RCU_SCHEDULER_INACTIVE.  However the warnings is not
actually be printed because the debug_lockdep_rcu_enabled() returns
false, exactly because the rcu_scheduler_active variable is still equal
to RCU_SCHEDULER_INACTIVE.

This commit therefore replaces RCU_LOCKDEP_WARN() with WARN_ONCE()
to force these warnings to actually be printed.

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 60c9eac..ae83960 100644 (file)
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -171,7 +171,7 @@ static void call_rcu_tasks_generic(struct rcu_head *rhp, rcu_callback_t func,
 static void synchronize_rcu_tasks_generic(struct rcu_tasks *rtp)
 {
        /* Complain if the scheduler has not started.  */
-       RCU_LOCKDEP_WARN(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE,
+       WARN_ONCE(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE,
                         "synchronize_rcu_tasks called too soon");
 
        /* Wait for the grace period. */