From: Zqiang <qiang1.zhang@intel.com>
Date: Tue, 12 Jul 2022 08:26:05 +0000 (+0800)
Subject: rcu-tasks: Convert RCU_LOCKDEP_WARN() to WARN_ONCE()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7ed95b080334e1c9ee13a727fae80cf3f8a2dcb4;p=linux.git

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 60c9eacac25bb..ae8396032b5da 100644
--- 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. */