--- cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c	(revision 348482)
+++ cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c	(working copy)
@@ -89,7 +89,7 @@ 
 #include <libshare.h>
 #define	MAXISALEN	257	/* based on sysinfo(2) man page */
 
-static int mount_tp_nthr = 512; /* tpool threads for multi-threaded mounting */
+static int mount_tp_nthr = 1; /* tpool threads for multi-threaded mounting */
 
 static void zfs_mount_task(void *);
 static int zfs_share_proto(zfs_handle_t *, zfs_share_proto_t *);