Remove Userspace-RCU signal variant

The signal variant of Userspace-RCU has been deprecated upstream.
Remove the support for compiling with it from configure.ac.

diff --git a/configure.ac b/configure.ac
index 4837cc549ba44705a9ad6a1750acc5affa4ed7db..704ffa3dcdaae2b024039386c14976474fc0a067 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -204,10 +204,10 @@ AS_IF([test -z "$PKG_CONFIG"],
 #
 # Pick Userspace-RCU flavor (developer only option)
 #
-# [pairwise: --with-liburcu=membarrier, --with-liburcu=qsbr, --with-liburcu=mb, --with-liburcu=signal, --with-liburcu=bp]
+# [pairwise: --with-liburcu=membarrier, --with-liburcu=qsbr, --with-liburcu=mb, --with-liburcu=bp]
 AC_ARG_WITH([liburcu],
            [AS_HELP_STRING([--with-liburcu=FLAVOR],
-                            [Build with Userspace-RCU variant (developer-only option) (membarrier|qsbr|mb|signal|bp) [default=membarrier]]))],
+                            [Build with Userspace-RCU variant (developer-only option) (membarrier|qsbr|mb|bp) [default=membarrier]]))],
            [], [with_liburcu=membarrier])
 
 AC_MSG_CHECKING([liburcu flavor])
@@ -221,9 +221,6 @@ AS_CASE([$with_liburcu],
        [mb],
        [RCU_FLAVOR="liburcu-mb"
         AC_DEFINE([RCU_MB], [1], [Build with mb Userspace-RCU flavor])],
-       [signal],
-       [RCU_FLAVOR="liburcu-signal"
-        AC_DEFINE([RCU_SIGNAL], [1], [Build with signal Userspace-RCU flavor])],
        [bp],
        [RCU_FLAVOR="liburcu-bp"
         AC_DEFINE([RCU_BP], [1], [Build with bulletproof Userspace-RCU flavor])],