[src/trunk]: src/usr.bin/rump_allserver Add note about block device properties.

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

details:   https://anonhg.NetBSD.org/src/rev/145e88ad6023
branches:  trunk
changeset: 762877:145e88ad6023
user:      pooka <pooka%NetBSD.org@localhost>
date:      Fri Mar 04 09:10:33 2011 +0000

description:
Add note about block device properties.

>From discussion with <riz>.

diffstat:

 usr.bin/rump_allserver/rump_allserver.1 |  8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diffs (22 lines):

diff -r af9a9bb0dab3 -r 145e88ad6023 usr.bin/rump_allserver/rump_allserver.1
--- a/usr.bin/rump_allserver/rump_allserver.1   Fri Mar 04 09:04:06 2011 +0000
+++ b/usr.bin/rump_allserver/rump_allserver.1   Fri Mar 04 09:10:33 2011 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: rump_allserver.1,v 1.17 2011/02/23 19:59:18 pooka Exp $
+.\"    $NetBSD: rump_allserver.1,v 1.18 2011/03/04 09:10:33 pooka Exp $
 .\"
 .\" Copyright (c) 2010 Antti Kantee.  All rights reserved.
 .\"
@@ -125,6 +125,12 @@
 .Dq reg
 for block device, character device and regular file, respectively.
 The default is a block device.
+.Pp
+Note: the contents of block devices are cached in the rump kernel's
+buffer cache.
+To avoid cache incoherency, it is advisable not to access a file
+through the host namespace while it is mapped as a block device in
+a running rump kernel.
 .El
 .Pp
 In case