[src/trunk]: src/lib/librumpuser Join today's manpage mania by updating this ...

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

details:   https://anonhg.NetBSD.org/src/rev/db5df3b822b7
branches:  trunk
changeset: 752577:db5df3b822b7
user:      pooka <pooka%NetBSD.org@localhost>
date:      Mon Mar 01 17:20:44 2010 +0000

description:
Join today's manpage mania by updating this to reflect the current
situation a "little" better.

diffstat:

 lib/librumpuser/rumpuser.3 |  42 ++++++++++++++++++++++++++++--------------
 1 files changed, 28 insertions(+), 14 deletions(-)

diffs (67 lines):

diff -r 32e9d4573816 -r db5df3b822b7 lib/librumpuser/rumpuser.3
--- a/lib/librumpuser/rumpuser.3        Mon Mar 01 17:06:18 2010 +0000
+++ b/lib/librumpuser/rumpuser.3        Mon Mar 01 17:20:44 2010 +0000
@@ -1,6 +1,6 @@
-.\"     $NetBSD: rumpuser.3,v 1.1 2010/02/26 18:54:20 pooka Exp $
+.\"     $NetBSD: rumpuser.3,v 1.2 2010/03/01 17:20:44 pooka Exp $
 .\"
-.\" Copyright (c) 2008 Antti Kantee.  All rights reserved.
+.\" Copyright (c) 2010 Antti Kantee.  All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
@@ -23,28 +23,42 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd July 28, 2008
+.Dd March 1, 2010
 .Dt RUMPUSER 3
 .Os
 .Sh NAME
 .Nm rumpuser
-.Nd rump user namespace helper routines
+.Nd rump hypervisor interface
 .Sh LIBRARY
 rump User Library (librumpuser, \-lrumpuser)
 .Sh SYNOPSIS
 .In rump/rumpuser.h
 .Sh DESCRIPTION
 .Nm
-is a user namespace helper library for runnable userspace meta programs.
-From rump emulation code compiled with
-.Dv -D_KERNEL
-is it not possible to directly call routines such as system calls
-for reading and writing files or devices.
-This is where
+is the hypervisor interface for
+.Xr rump 3
+style kernel virtualization.
+A virtual rump kernel can make calls to the host operating system
+libraries and kernel (system calls) using
 .Nm
-comes into play by providing a bridge between the two namespaces.
-Another example of its services is a way to call pthread routines,
-used for emulating kernel threads and synchronization mechanisms
-in rump.
+interfaces.
+Any "slow" hypervisor calls such as file I/O, sychronization wait,
+or sleep will cause rump to unschedule the calling kernel thread
+from the virtual CPU and free it for other consumers.
+When the hypervisor call returns to the kernel, a new scheduling
+operation takes place.
+.Pp
+For example, rump implements kernel threads directly as hypervisor
+calls to host
+.Xr pthread 3 .
+This avoids the common virtualization drawback of multiple overlapping
+and possibly conflicting implementations of same functionality in
+the software stack.
+.Pp
+The
+.Nm
+interface is still under development and interface documentation
+is available only in source form from
+.Pa src/lib/librumpuser .
 .Sh SEE ALSO
 .Xr rump 3