[src/trunk]: src/share/man/man9 Clarify reference counting of uvm_map.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/634dc54baea8
branches:  trunk
changeset: 834622:634dc54baea8
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 20 14:29:05 2018 +0000

description:
Clarify reference counting of uvm_map.

diffstat:

 share/man/man9/uvm_map.9 |  20 +++++++++++++++-----
 1 files changed, 15 insertions(+), 5 deletions(-)

diffs (35 lines):

diff -r f08095d33e28 -r 634dc54baea8 share/man/man9/uvm_map.9
--- a/share/man/man9/uvm_map.9  Mon Aug 20 14:23:27 2018 +0000
+++ b/share/man/man9/uvm_map.9  Mon Aug 20 14:29:05 2018 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: uvm_map.9,v 1.10 2017/05/20 08:00:47 wiz Exp $
+.\"    $NetBSD: uvm_map.9,v 1.11 2018/08/20 14:29:05 riastradh Exp $
 .\"
 .\" Copyright (c) 1998 Matthew R. Green
 .\" All rights reserved.
@@ -136,11 +136,21 @@
 The start address of the map will be returned in
 .Fa startp .
 .El
-Note that
+If
+.Fa uobj
+is supplied, then
 .Fn uvm_map
-does not add a reference to
-.Fa uobj ;
-it is the caller's responsibility to do so.
+.Em consumes
+the caller's reference to
+.Fa uobj
+on success;
+.Fn uvm_unmap
+will release it when removing this mapping.
+On failure,
+.Fn uvm_map
+leaves the reference count of
+.Fa uobj
+unmodified.
 .Pp
 .Fa align
 specifies alignment of mapping unless