[src/uebayasi-xip]: src/share/man/man9 Refer to cpu_switchto(9) instead of no...

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

details:   https://anonhg.NetBSD.org/src/rev/d6d892b25ebb
branches:  uebayasi-xip
changeset: 751653:d6d892b25ebb
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Tue Apr 13 05:41:54 2010 +0000

description:
Refer to cpu_switchto(9) instead of nonexistent cpu_switch(x).

diffstat:

 share/man/man9/cpu_lwp_fork.9 |  102 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 102 insertions(+), 0 deletions(-)

diffs (106 lines):

diff -r af2e771ae2e0 -r d6d892b25ebb share/man/man9/cpu_lwp_fork.9
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/share/man/man9/cpu_lwp_fork.9     Tue Apr 13 05:41:54 2010 +0000
@@ -0,0 +1,102 @@
+.\"     $NetBSD: cpu_lwp_fork.9,v 1.4.2.2 2010/04/13 05:41:54 jruoho Exp $
+.\"
+.\" Copyright (c) 2002, 2005, 2006 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Gregory McGarry; and Rui Paulo.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd April 13, 2010
+.Dt CPU_LWP_FORK 9
+.Os
+.Sh NAME
+.Nm cpu_lwp_fork ,
+.Nm child_return ,
+.Nm proc_trampoline
+.Nd finish a fork operation
+.Sh SYNOPSIS
+.In sys/proc.h
+.Ft void
+.Fn cpu_lwp_fork "struct lwp *l1" "struct lwp *l2" "void *stack" \
+"size_t stacksize" "void (*func)(void *)" "void *arg"
+.Ft void
+.Fn child_return "void *arg"
+.Sh DESCRIPTION
+.Fn cpu_lwp_fork
+is the machine-dependent portion of
+.Fn fork1
+which finishes a fork operation, with child lwp
+.Fa l2
+nearly set up.
+It copies and updates the PCB and trap frame from the parent
+.Fa l1 ,
+making the child ready to run.
+.Pp
+.Fn cpu_lwp_fork
+rigs the child's kernel stack so that it will start in
+.Fn proc_trampoline .
+.Fn proc_trampoline
+does not have a normal calling sequence and is entered by
+.Fn cpu_switch .
+If an alternate user-level stack is requested (with non-zero values
+in both the
+.Fa stack
+and
+.Fa stacksize
+arguments), the user stack pointer is set up accordingly.
+.Pp
+After being entered by
+.Fn cpu_switch
+and while running in user context (within the kernel)
+.Fn proc_trampoline
+will invoke the function
+.Fa func
+with the argument
+.Fa arg .
+If a kernel thread is being created, the return path and argument
+are specified with
+.Fa func
+and
+.Fa arg .
+If a user process is being created,
+.Fn fork1
+will pass
+.Fn child_return
+and
+.Fa l2
+to
+.Fn cpu_lwp_fork
+as
+.Fa func
+and
+.Fa arg
+respectively.
+This causes the newly-created child process to go directly to user
+level with an apparent return value of 0 from
+.Xr fork 2 ,
+while the parent process returns normally.
+.Sh SEE ALSO
+.Xr fork 2 ,
+.Xr cpu_switchto 9 ,
+.Xr fork1 9