Allow forcing the use of sys membarrier

[urcu.git] / src / urcu.c

diff --git a/src/urcu.c b/src/urcu.c
index ccd9706dda6fe6a8b6bfcba2fced7893054cf3ae..a81b12913e92d86b8eea95203f8d9054de8dda52 100644 (file)
--- a/src/urcu.c
+++ b/src/urcu.c
@@ -77,7 +77,9 @@ enum membarrier_cmd {
 
 #ifdef RCU_MEMBARRIER
 static int init_done;
-int rcu_has_sys_membarrier;
+#ifndef CONFIG_RCU_FORCE_SYS_MEMBARRIER
+int rcu_has_sys_membarrier_memb;
+#endif
 
 void __attribute__((constructor)) rcu_init(void);
 #endif
@@ -160,7 +162,7 @@ static void mutex_unlock(pthread_mutex_t *mutex)
 #ifdef RCU_MEMBARRIER
 static void smp_mb_master(void)
 {
-       if (caa_likely(rcu_has_sys_membarrier))
+       if (caa_likely(rcu_has_sys_membarrier_memb))
                (void) membarrier(MEMBARRIER_CMD_SHARED, 0);
        else
                cmm_smp_mb();
@@ -532,6 +534,23 @@ void rcu_unregister_thread(void)
 }
 
 #ifdef RCU_MEMBARRIER
+
+#ifdef CONFIG_RCU_FORCE_SYS_MEMBARRIER
+static
+void rcu_sys_membarrier_status(int available)
+{
+       if (!available)
+               abort();
+}
+#else
+static
+void rcu_sys_membarrier_status(int available)
+{
+       if (available)
+               rcu_has_sys_membarrier_memb = 1;
+}
+#endif
+
 void rcu_init(void)
 {
        int ret;
@@ -540,9 +559,7 @@ void rcu_init(void)
                return;
        init_done = 1;
        ret = membarrier(MEMBARRIER_CMD_QUERY, 0);
-       if (ret >= 0 && (ret & MEMBARRIER_CMD_SHARED)) {
-               rcu_has_sys_membarrier = 1;
-       }
+       rcu_sys_membarrier_status(ret >= 0 && (ret & MEMBARRIER_CMD_SHARED));
 }
 #endif