Index: sys/kern/subr_log.c
===================================================================
--- sys/kern/subr_log.c	(revision 210019)
+++ sys/kern/subr_log.c	(working copy)
@@ -87,7 +87,7 @@
 /* Times per second to check for a pending syslog wakeup. */
 static int	log_wakeups_per_second = 5;
 SYSCTL_INT(_kern, OID_AUTO, log_wakeups_per_second, CTLFLAG_RW,
-    &log_wakeups_per_second, 0, "");
+    &log_wakeups_per_second, 0, "Times per second to check for a pending syslog wakeup");
 
 /*ARGSUSED*/
 static	int
Index: sys/kern/kern_thread.c
===================================================================
--- sys/kern/kern_thread.c	(revision 210019)
+++ sys/kern/kern_thread.c	(working copy)
@@ -72,7 +72,7 @@
 
 int max_threads_hits;
 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD,
-	&max_threads_hits, 0, "");
+	&max_threads_hits, 0, "max_threads_per_proc rearched counter");
 
 TAILQ_HEAD(, thread) zombie_threads = TAILQ_HEAD_INITIALIZER(zombie_threads);
 static struct mtx zombie_lock;
Index: sys/kern/kern_shutdown.c
===================================================================
--- sys/kern/kern_shutdown.c	(revision 210019)
+++ sys/kern/kern_shutdown.c	(working copy)
@@ -603,7 +603,7 @@
 static int poweroff_delay = POWEROFF_DELAY;
 
 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
-	&poweroff_delay, 0, "");
+	&poweroff_delay, 0, "Delay before poweroff to write disks caches (usecs)");
 
 static void
 poweroff_wait(void *junk, int howto)
@@ -623,7 +623,7 @@
  */
 static int kproc_shutdown_wait = 60;
 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
-    &kproc_shutdown_wait, 0, "");
+    &kproc_shutdown_wait, 0, "Shutdown wait for system procs and threads");
 
 void
 kproc_shutdown(void *arg, int howto)
Index: sys/kern/vfs_syscalls.c
===================================================================
--- sys/kern/vfs_syscalls.c	(revision 210019)
+++ sys/kern/vfs_syscalls.c	(working copy)
@@ -878,7 +878,11 @@
 static int chroot_allow_open_directories = 1;
 
 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
-     &chroot_allow_open_directories, 0, "");
+     &chroot_allow_open_directories, 0, "This sysctl determines if we will allow a process to chroot(2) if it\n"
+	"has a directory open:\n"
+	"0: disallowed for all processes\n"
+	"1: allowed for processes that were not already chroot(2)'ed\n"
+	"2: allowed for all processes");
 
 /*
  * Change notion of root (``/'') directory.