X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=configure.ac;h=4f61599cfa0e5cf786b68ff3e5840024adafdf4d;hb=97707db5a1d8e2bd9b3be01ef4b5085deaf9dbd4;hp=c95feac27d1145f89030116b9d425b6d3c821e26;hpb=82f3d47ca95b6a662c2a75e61e9e014a1e3866f7;p=elogind.git

diff --git a/configure.ac b/configure.ac
index c95feac27..4f61599cf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -20,7 +20,7 @@
 AC_PREREQ([2.64])
 
 AC_INIT([elogind],
-        [231.1],
+        [231.4],
         [https://github.com/elogind/elogind/issues],
         [elogind],
         [https://github.com/elogind/elogind])
@@ -111,20 +111,52 @@ fi
 
 
 # ------------------------------------------------------------------------------
-# Find running cgroup controller
+# Let users set the cgroup controller to use, in case the target controller
+# isn't currently running the show.
+# Example: Gentoo Linux, user wants to switch from systemd to openrc+elogind,
+#          and emerges elogind before having booted the machine with openrc.
+#          See: https://github.com/elogind/elogind/issues/18
 with_cgroupctrl=
-AS_IF(  [test -f /proc/self/cgroup], [
-        # If the init system is a cgroup controler, it will be position 1.
-        # Secondary controllers, like cgmanager, do not work.
-        with_cgroupctrl=`grep "^1:name=" /proc/self/cgroup | cut -d ':' -f 2`
-        AS_IF(  [test -z "$with_cgroupctrl"], [
-                # Try to be our own cgroup controller
-                with_cgroupctrl="name=elogind"
+AC_ARG_WITH([cgroup-controller],
+            AS_HELP_STRING([--with-cgroup-controller=name],
+            [Set the name of the cgroup controller to use.
+             Use this when the autodetection fails, or you plan to use your system with a different controller than the one in place now.
+             The value 'auto' (default) detects the running controller.
+             The values 'none' and 'elogind' will cause elogind to be its own (very limited) controller.
+             When elogind shall be its own controller, there *MUST NOT* be any other controller running!
+             Another popular controller would be 'openrc'.]),
+            [with_cgroupctrl=$withval],
+            [with_cgroupctrl=auto])
+
+# ------------------------------------------------------------------------------
+# Find running cgroup controller, if none was set
+AS_IF(  [test "x$with_cgroupctrl" = "xauto"], [
+        AS_IF([test -f /proc/self/cgroup], [
+                # If the init system is a cgroup controler, it will be position 1.
+                # Secondary controllers, like cgmanager, do not work.
+                with_cgroupctrl=`grep "^1:name=" /proc/self/cgroup | \
+                        sed -n 's/.*=//p' | sed -e 's/:.*$//'`
+                AS_IF(  [test -z "$with_cgroupctrl"], [
+                        # Try to be our own cgroup controller
+                        with_cgroupctrl="elogind"
+                        ])
+        ], [
+                # 'auto' but no cgroup fs is a problem.
+                with_cgroupctrl=""
         ])
 ])
-AS_IF(  [test -z "$with_cgroupctrl"],
-        AC_MSG_ERROR([No running cgroup controller found]))
 
+# If the user specified 'none', switch to 'elogind'.
+# 'none' is allowed, as this means "there is no controller now"
+AS_IF(  [test "x$with_cgroupctrl" = "xnone"], [with_cgroupctrl=elogind])
+
+# If this was not possible, /proc/self/cgroup not mounted yet, and 'auto'
+# chosen, error out.
+AS_IF(  [test -z "$with_cgroupctrl"],
+        AC_MSG_ERROR([No running cgroup controller found]), [
+        # Otherwise add the 'name=' prefix
+        with_cgroupctrl="name=$with_cgroupctrl"
+])
 
 # ------------------------------------------------------------------------------
 address_sanitizer_cflags=