[PATCH tip/core/rcu 17/26] lockdep: Complain only once about RCU in extended quiescent state

From: paulmck
Date: Mon Jun 22 2020 - 20:22:46 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxxxxxxx
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
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