extern "C" {
#endif
+/* Default is RCU_MEMBARRIER */
+#if !defined(RCU_MEMBARRIER) && !defined(RCU_MB) && !defined(RCU_SIGNAL)
+#define RCU_MEMBARRIER
+#endif
+
+#ifdef RCU_MEMBARRIER
+#include <unistd.h>
+#include <sys/syscall.h>
+
+/* If the headers do not support SYS_membarrier, statically use RCU_MB */
+#ifdef SYS_membarrier
+# define MEMBARRIER_EXPEDITED (1 << 0)
+# define MEMBARRIER_DELAYED (1 << 1)
+# define membarrier(...) syscall(__NR_membarrier, __VA_ARGS__)
+#else
+# undef RCU_MEMBARRIER
+# define RCU_MB
+#endif
+#endif
+
/*
* This code section can only be included in LGPL 2.1 compatible source code.
* See below for the function call wrappers which can be used in code meant to
#define YIELD_WRITE (1 << 1)
/*
- * Updates without RCU_MB are much slower. Account this in
- * the delay.
+ * Updates with RCU_SIGNAL are much slower. Account this in the delay.
*/
-#ifdef RCU_MB
+#ifdef RCU_SIGNAL
/* maximum sleep delay, in us */
-#define MAX_SLEEP 50
-#else
#define MAX_SLEEP 30000
+#else
+#define MAX_SLEEP 50
#endif
extern unsigned int yield_active;
}
#endif
+#ifdef RCU_MEMBARRIER
+extern int has_sys_membarrier;
+
+static inline void smp_mb_light()
+{
+ if (likely(has_sys_membarrier))
+ barrier();
+ else
+ smp_mb();
+}
+#endif
+
#ifdef RCU_MB
static inline void smp_mb_light()
{
smp_mb();
}
-#else
+#endif
+
+#ifdef RCU_SIGNAL
static inline void smp_mb_light()
{
barrier();