[PATCH 06/11] rcu: Make srcu_read_lock_held() call common lockdep-enabled function

From: Frederic Weisbecker
Date: Fri Oct 07 2011 - 12:22:39 EST

A common debug_lockdep_rcu_enabled() function is used to check whether
RCU lockdep splats should be reported, but srcu_read_lock() does not
use it. This commit therefore brings srcu_read_lock_held() up to date.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
include/linux/srcu.h | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index 553c003..05d34cf 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -84,6 +84,9 @@ long srcu_batches_completed(struct srcu_struct *sp);
* this assumes we are in an SRCU read-side critical section unless it can
* prove otherwise.
+ * Checks debug_lockdep_rcu_enabled() to prevent false positives during boot
+ * and while lockdep is disabled.
+ *
* Note that if the CPU is in the idle loop from an RCU point of view
* (ie: that we are in the section between rcu_idle_enter() and rcu_idle_exit())
* then srcu_read_lock_held() returns false even if the CPU did an srcu_read_lock().
@@ -101,7 +104,7 @@ static inline int srcu_read_lock_held(struct srcu_struct *sp)
if (rcu_is_cpu_idle())
return 0;

- if (!debug_locks)
+ if (!debug_lockdep_rcu_enabled())
return 1;

return lock_is_held(&sp->dep_map);

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