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To:     rcu@vger.kernel.org
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        "Paul E. McKenney" <paulmck@kernel.org>,
        Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>
Subject: [PATCH tip/core/rcu 17/26] lockdep: Complain only once about RCU in extended quiescent state
Date:   Mon, 22 Jun 2020 17:21:38 -0700
Message-Id: <20200623002147.25750-17-paulmck@kernel.org>
In-Reply-To: <20200623002128.GA25456@paulmck-ThinkPad-P72>
References: <20200623002128.GA25456@paulmck-ThinkPad-P72>
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From: "Paul E. McKenney" <paulmck@kernel.org>

Currently, lockdep_rcu_suspicious() complains twice about RCU read-side
critical sections being invoked from within extended quiescent states,
for example:

	RCU used illegally from idle CPU!
	rcu_scheduler_active = 2, debug_locks = 1
	RCU used illegally from extended quiescent state!

This commit therefore saves a couple lines of code and one line of
console-log output by eliminating the first of these two complaints.

Link: https://lore.kernel.org/lkml/87wo4wnpzb.fsf@nanos.tec.linutronix.de
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/locking/lockdep.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 29a8de4..0a7549d 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -5851,9 +5851,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 	pr_warn("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
 	       !rcu_lockdep_current_cpu_online()
 			? "RCU used illegally from offline CPU!\n"
-			: !rcu_is_watching()
-				? "RCU used illegally from idle CPU!\n"
-				: "",
+			: "",
 	       rcu_scheduler_active, debug_locks);
 
 	/*
-- 
2.9.5