+# Allow overriding storage used for TLS variables.
+AC_ARG_ENABLE([compiler-tls],
+ AS_HELP_STRING([--disable-compiler-tls], [Use pthread_getspecific() to emulate Thread Local Storage (TLS) variables.]),
+ [def_compiler_tls=$enableval],
+ [def_compiler_tls="yes"])
+
+# If not overridden, use ax_tls.m4 to check if TLS is available.
+AS_IF([test "x$def_compiler_tls" = "xyes"],
+ [AX_TLS([def_tls_detect=$ac_cv_tls], [:])],
+ [:])
+
+AS_IF([test "x$def_tls_detect" = "x"],
+ [:],
+ [AC_DEFINE_UNQUOTED([CONFIG_RCU_TLS], $def_tls_detect)])