+
+bool cg_is_unified_systemd_controller_wanted(void) {
+ static thread_local int wanted = -1;
+ int r, unified;
+
+ /* If the unified hierarchy is requested in full, no need to
+ * bother with this. */
+ if (cg_is_unified_wanted())
+ return 0;
+
+ /* If the hierarchy is already mounted, then follow whatever
+ * was chosen for it. */
+ unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
+ if (unified >= 0)
+ return unified;
+
+ /* Otherwise, let's see what the kernel command line has to
+ * say. Since checking that is expensive, let's cache the
+ * result. */
+ if (wanted >= 0)
+ return wanted;
+
+ r = get_proc_cmdline_key("systemd.legacy_systemd_cgroup_controller", NULL);
+ if (r > 0) {
+ wanted = false;
+ } else {
+ _cleanup_free_ char *value = NULL;
+
+ r = get_proc_cmdline_key("systemd.legacy_systemd_cgroup_controller=", &value);
+ if (r < 0)
+ return true;
+
+ if (r == 0)
+ wanted = true;
+ else
+ wanted = parse_boolean(value) <= 0;
+ }
+
+ return wanted;
+}
+
+bool cg_is_legacy_systemd_controller_wanted(void) {
+ return cg_is_legacy_wanted() && !cg_is_unified_systemd_controller_wanted();