[PATCH, RFC, -rt] Make lockdep-RCU insist on rcu_read_lock_bh()

From: Paul E. McKenney
Date: Thu Oct 06 2011 - 20:44:59 EST

rcu: Make -rt complain about lack of rcu_read_lock_bh()

Mainline permits local_bh_disable() to be used in place of
rcu_read_lock_bh(), but this fails for CONFIG_PREEMPT_RT_FULL. This
commit therefore makes rcu_read_lock_bh_held() insist on
rcu_read_lock_bh() for CONFIG_PREEMPT_RT_FULL.

Signed-off-by: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 5e0577b..e91a85d 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -89,7 +89,11 @@ int rcu_read_lock_bh_held(void)
if (!debug_lockdep_rcu_enabled())
return 1;
+ return lock_is_held(&rcu_bh_lock_map);
return in_softirq() || irqs_disabled();

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/