Add compiler barriers to read-side for mutex ordering

[urcu.git] / urcu-qsbr-static.h

diff --git a/urcu-qsbr-static.h b/urcu-qsbr-static.h
index 041361799b89694b8f9e8c9f7af0d142d040a44e..147eb18b94357ee885216d3db65f252d54143944 100644 (file)
--- a/urcu-qsbr-static.h
+++ b/urcu-qsbr-static.h
@@ -187,10 +187,12 @@ static inline void _rcu_thread_offline(void)
        STORE_SHARED(rcu_reader.ctr, 0);
        smp_mb();       /* write rcu_reader.ctr before read futex */
        wake_up_gp();
+       barrier();      /* Ensure the compiler does not reorder us with mutex */
 }
 
 static inline void _rcu_thread_online(void)
 {
+       barrier();      /* Ensure the compiler does not reorder us with mutex */
        _STORE_SHARED(rcu_reader.ctr, LOAD_SHARED(rcu_gp_ctr));
        smp_mb();
 }