+ /* Close the read side of the KUC pipe. This should be done
+ * before unregistering to avoid deadlock: a ldlm_cb thread
+ * enters libcfs_kkuc_group_put() acquires kg_sem and blocks
+ * in pipe_write() due to full pipe; then we attempt to
+ * unregister and block on kg_sem. */
+ libcfs_ukuc_stop(&ct->kuc);
+