path: root/Documentation/RCU/checklist.txt
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Diffstat (limited to 'Documentation/RCU/checklist.txt')
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt
index e118a7c1a092..49e27cc19385 100644
--- a/Documentation/RCU/checklist.txt
+++ b/Documentation/RCU/checklist.txt
@@ -177,3 +177,9 @@ over a rather long period of time, but improvements are always welcome!
If you want to wait for some of these other things, you might
instead need to use synchronize_irq() or synchronize_sched().
+12. Any lock acquired by an RCU callback must be acquired elsewhere
+ with irq disabled, e.g., via spin_lock_irqsave(). Failing to
+ disable irq on a given acquisition of that lock will result in
+ deadlock as soon as the RCU callback happens to interrupt that
+ acquisition's critical section.