Index: share/man/man9/timeout.9
===================================================================
--- share/man/man9/timeout.9	(revision 254669)
+++ share/man/man9/timeout.9	(working copy)
@@ -38,6 +38,7 @@
 .Nm callout_handle_init ,
 .Nm callout_init ,
 .Nm callout_init_mtx ,
+.Nm callout_init_rm ,
 .Nm callout_init_rw ,
 .Nm callout_stop ,
 .Nm callout_drain ,
@@ -73,6 +74,8 @@ struct callout_handle handle = CALLOUT_HANDLE_INIT
 .Fn callout_init "struct callout *c" "int mpsafe"
 .Ft void
 .Fn callout_init_mtx "struct callout *c" "struct mtx *mtx" "int flags"
+.Fn void
+.Fn callout_init_rm "struct callout *c" "struct rmlock *rm" "int flags"
 .Ft void
 .Fn callout_init_rw "struct callout *c" "struct rwlock *rw" "int flags"
 .Ft int
@@ -203,6 +206,7 @@ Thus they are protected from re-entrancy.
 The functions
 .Fn callout_init ,
 .Fn callout_init_mtx ,
+.Fn callout_init_rm ,
 .Fn callout_init_rw ,
 .Fn callout_stop ,
 .Fn callout_drain ,
@@ -252,15 +256,25 @@ after the callout function returns.
 .Pp
 The
 .Fn callout_init_rw
-function serves the need of using rwlocks in conjunction with callouts.
-The function does basically the same as
+and the 
+.Fn callout_init_rm
+fuctions serve the need of using rwlocks and rmlocks in conjunction
+with callouts.
+The functions do basically the same as
 .Fn callout_init_mtx
 with the possibility of specifying an extra
 .Fa rw
+or
+.Fa rm
 argument.
-The usable lock classes are currently limited to mutexes and rwlocks,
-because callout handlers run in softclock swi, so they cannot sleep nor
-acquire sleepable locks like sx or lockmgr.
+If an
+.Fa rm
+argument is specified, the lock should be created without passing the
+.It Dv RM_SLEEPABLE
+flags.
+The usable lock classes are currently limited to mutexes, rwlocks and
+non-sleepable rmlocks, because callout handlers run in softclock swi,
+so they cannot sleep nor acquire sleepable locks like sx or lockmgr.
 The following
 .Fa flags
 may be specified:
Index: sys/sys/callout.h
===================================================================
--- sys/sys/callout.h	(revision 254669)
+++ sys/sys/callout.h	(working copy)
@@ -71,6 +71,9 @@ void	_callout_init_lock(struct callout *, struct l
 #define	callout_init_mtx(c, mtx, flags)					\
 	_callout_init_lock((c), ((mtx) != NULL) ? &(mtx)->lock_object :	\
 	    NULL, (flags))
+#define	callout_init_rm(c, rm, flags)
+	_callout_init_lock((c), ((rm != NULL) ? &(rm)->lock_object : \
+	    NULL, (flags))
 #define	callout_init_rw(c, rw, flags)					\
 	_callout_init_lock((c), ((rw) != NULL) ? &(rw)->lock_object :	\
 	   NULL, (flags))