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authorPaul E. McKenney <paulmck@kernel.org>2021-07-19 11:52:12 -0700
committerPaul E. McKenney <paulmck@kernel.org>2021-08-06 13:41:49 -0700
commit521c89b3a4022269c75b35062358d1dae4ebfa79 (patch)
tree38ed225f1b20fe03e3f3641f03b7f0a599bb0e8d /kernel
parent508958259bb3d9ca4ec37f0abdb211e9a6f3daa2 (diff)
rcu: Print human-readable message for schedule() in RCU reader
The WARN_ON_ONCE() invocation within the CONFIG_PREEMPT=y version of rcu_note_context_switch() triggers when there is a voluntary context switch in an RCU read-side critical section, but there is quite a gap between the output of that WARN_ON_ONCE() and this RCU-usage error. This commit therefore converts the WARN_ON_ONCE() to a WARN_ONCE() that explicitly describes the problem in its message. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/rcu/tree_plugin.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 83a702a4e296..e8b45ab72a79 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -346,7 +346,7 @@ void rcu_note_context_switch(bool preempt)
trace_rcu_utilization(TPS("Start context switch"));
lockdep_assert_irqs_disabled();
- WARN_ON_ONCE(!preempt && rcu_preempt_depth() > 0);
+ WARN_ONCE(!preempt && rcu_preempt_depth() > 0, "Voluntary context switch within RCU read-side critical section!");
if (rcu_preempt_depth() > 0 &&
!t->rcu_read_unlock_special.b.blocked) {