Fix: only define membarrier system call on Linux

[urcu.git] / urcu / arch / x86.h

diff --git a/urcu/arch/x86.h b/urcu/arch/x86.h
index b4d3694fdffb896fa3773f30ad8d0777ae9836a4..aac8ca1384b63f4ce321680cffbcaca661a0f16c 100644 (file)
--- a/urcu/arch/x86.h
+++ b/urcu/arch/x86.h
@@ -91,15 +91,13 @@ static inline caa_cycles_t caa_get_cycles(void)
 }
 
 /*
- * Define the membarrier system call number if not yet available in the
- * system headers.
+ * On Linux, define the membarrier system call number if not yet available in
+ * the system headers.
  */
+#if (defined(__linux__) && !defined(__NR_membarrier))
 #if (CAA_BITS_PER_LONG == 32)
-#ifndef __NR_membarrier
 #define __NR_membarrier                375
-#endif
 #else
-#ifndef __NR_membarrier
 #define __NR_membarrier                324
 #endif
 #endif