Allowing changing Userspace-RCU variant only in developer mode

The Userspace-RCU variants other than membarrier is untested and at
least in QSBR case it's broken.  Allow changing the Userspace-RCU
variant only in the developer's mode.

diff --git a/configure.ac b/configure.ac
index cce13b499fedd8051916547e33c1f3024b1123eb..4837cc549ba44705a9ad6a1750acc5affa4ed7db 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -207,7 +207,7 @@ AS_IF([test -z "$PKG_CONFIG"],
 # [pairwise: --with-liburcu=membarrier, --with-liburcu=qsbr, --with-liburcu=mb, --with-liburcu=signal, --with-liburcu=bp]
 AC_ARG_WITH([liburcu],
            [AS_HELP_STRING([--with-liburcu=FLAVOR],
-                            [Build with Userspace-RCU variant (membarrier|qsbr|mb|signal|bp) [default=membarrier]]))],
+                            [Build with Userspace-RCU variant (developer-only option) (membarrier|qsbr|mb|signal|bp) [default=membarrier]]))],
            [], [with_liburcu=membarrier])
 
 AC_MSG_CHECKING([liburcu flavor])
@@ -229,6 +229,9 @@ AS_CASE([$with_liburcu],
         AC_DEFINE([RCU_BP], [1], [Build with bulletproof Userspace-RCU flavor])],
        [AC_MSG_ERROR([Invalid Userspace-RCU flavor picked])])
 
+AS_IF([test "$with_liburcu" != "membarrier" && test "$enable_developer" != "yes"],
+      [AC_MSG_ERROR([Changing Userspace-RCU variant is allowed only in developer mode])])
+
 AC_MSG_RESULT([$RCU_FLAVOR])
 
 #