Allow forcing the use of sys membarrier

[urcu.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index 7a992edf6946e5464e76c61cd56ae74203542a8f..8ac0c4172682668f70fd1e9d158d8c15f2b931e7 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -25,6 +25,15 @@ AH_TEMPLATE([CONFIG_RCU_COMPAT_ARCH], [Compatibility mode for i386 which lacks c
 AH_TEMPLATE([CONFIG_RCU_ARM_HAVE_DMB], [Use the dmb instruction if available for use on ARM.])
 AH_TEMPLATE([CONFIG_RCU_TLS], [TLS provided by the compiler.])
 AH_TEMPLATE([CONFIG_RCU_HAVE_CLOCK_GETTIME], [clock_gettime() is detected.])
+AH_TEMPLATE([CONFIG_RCU_FORCE_SYS_MEMBARRIER], [Require the operating system to support the membarrier system call for default and bulletproof flavors.])
+
+# Allow requiring the operating system to support the membarrier system
+# call. Applies to default and bulletproof flavors.
+AC_ARG_ENABLE([sys-membarrier-fallback],
+       AS_HELP_STRING([--disable-sys-membarrier-fallback], [Abort if sys-membarrier is needed but not available rather than using a fallback.]),
+       [def_sys_membarrier_fallback=$enableval],
+       [def_sys_membarrier_fallback="yes"])
+AS_IF([test "x$def_sys_membarrier_fallback" != "xyes"], [AC_DEFINE([CONFIG_RCU_FORCE_SYS_MEMBARRIER], [1])])
 
 # Allow overriding storage used for TLS variables.
 AC_ARG_ENABLE([compiler-tls],