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Diffstat (limited to 'static/openbsd/man9/kthread.9')
| -rw-r--r-- | static/openbsd/man9/kthread.9 | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/static/openbsd/man9/kthread.9 b/static/openbsd/man9/kthread.9 new file mode 100644 index 00000000..5556b093 --- /dev/null +++ b/static/openbsd/man9/kthread.9 @@ -0,0 +1,97 @@ +.\" $OpenBSD: kthread.9,v 1.10 2013/11/18 20:21:50 deraadt Exp $ +.\" +.\" Copyright (c) 1999 Marc Espie +.\" All rights reserved. +.\" +.\" 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 AUTHOR ``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 AUTHOR 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 $Mdocdate: November 18 2013 $ +.Dt KTHREAD 9 +.Os +.Sh NAME +.Nm kthread_create , +.Nm kthread_exit , +.Nm kthread_create_deferred +.Nd kernel threads +.Sh SYNOPSIS +.In sys/kthread.h +.Ft int +.Fn kthread_create "void (*func)(void *)" "void *arg" "struct proc **newpp" "const char *name" +.Ft void +.Fn kthread_exit "int ecode" +.Ft void +.Fn kthread_create_deferred "void (*func)(void *)" "void *arg" +.Sh DESCRIPTION +Kernel threads are system light-weight processes: cloned from process 0 +(the swapper), sharing its memory map and limits, but with a copy of its +file descriptor table. +They don't receive broadcast nor group signals and they can't be swapped. +.Pp +Any process can call +.Fn kthread_create +to create a kernel thread. +The new process starts up executing +.Fa func +with argument +.Fa arg . +If +.Fa newpp +is not +.Dv NULL , +it is filled with the address of the new process. +.Fa name +is used to name the process. +.Pp +A kernel thread will terminate by calling +.Fn kthread_exit , +with exit code +.Fa ecode . +.Pp +Since the system has to be up and running for creating +new processes, device drivers that want to create kernel threads early +(e.g., at attach time) may use +.Fn kthread_create_deferred +instead. +The system will call back the function +.Fa func +with argument +.Fa arg +when it can create threads, so it is up to +.Fa func +to call +.Fn kthread_create +at that point. +.Sh RETURN VALUES +Upon successful completion, +.Fn kthread_create +returns 0. +Otherwise, the following error values are returned: +.Bl -tag -width [EAGAIN] +.It Bq Er EAGAIN +The limit on the total number of system processes would be exceeded. +.El +.Sh SEE ALSO +.Xr fork1 9 +.Sh BUGS +There is currently no way to use +.Va ecode +to any sensible purpose from +.Fn kthread_exit . |
