[tip: core/rcu] lockdep: Complain only once about RCU in extended quiescent state

tip-bot2 for Paul E. McKenney
2020-07-31T09:24:34Z

The following commit has been merged into the core/rcu branch of tip:

Commit-ID: d29e0b26b020422cc51b5b51733cc50fcf443965
Gitweb: https://git.kernel.org/tip/d29e0b26b020422cc51b5b51733cc50fcf443965
Author: Paul E. McKenney <paulmck@kernel.org>
AuthorDate: Thu, 28 May 2020 08:49:29 -07:00
Committer: Paul E. McKenney <paulmck@kernel.org>
CommitterDate: Mon, 29 Jun 2020 11:58:51 -07:00

lockdep: Complain only once about RCU in extended quiescent state

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);

/*