add rc_cgroup option to allow disabling of cgroup default setup

Currently, cgroups are still in development, so we are not setting them
up by default. However, this default will be changed in the future.

This commit message and patch were updated by
William Hubbs <williamh@gentoo.org>.

X-Gentoo-Bug: 395079
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=395079

etc/rc.conf.Linux

@@ -22,3 +22,9 @@ rc_sys="@RC_SYS_DEFAULT@"
 # consolefont, numlock, etc ...)
 rc_tty_number=12
 
+# openrc can set up linux control groups the way the documentation in
+# the kernel recommends creating them.
+# Currently, this option is disabled by default, but it will be enabled
+# in the future, so if you would like to see how control groups will be
+# created, uncomment this line.
+#rc_cgroups="YES"

init.d/sysfs.in

@@ -64,6 +64,7 @@ mount_misc()
 
 mount_cgroups()
 {
+	yesno ${rc_cgroups:-NO} || return 0
 	if [ ! -e /proc/cgroups ]; then
 		return 0
 	fi