feat: Added NetBSD man pages

1 files changed, 222 insertions, 0 deletions

diff --git a/static/netbsd/man9/kthread.9 b/static/netbsd/man9/kthread.9
new file mode 100644
index 00000000..342c2a8e
--- /dev/null
+++ b/static/netbsd/man9/kthread.9
@@ -0,0 +1,222 @@
+.\"     $NetBSD: kthread.9,v 1.30 2020/08/01 09:50:42 wiz Exp $
+.\"
+.\" Copyright (c) 2000, 2007, 2008 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Gregory McGarry, and by Andrew Doran.
+.\"
+.\" 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 21, 2015
+.Dt KTHREAD 9
+.Os
+.Sh NAME
+.Nm kthread_create ,
+.Nm kthread_exit ,
+.Nm kthread_join ,
+.Nm kthread_fpu_enter ,
+.Nm kthread_fpu_exit
+.Nd kernel threads
+.Sh SYNOPSIS
+.In sys/kthread.h
+.Ft int
+.Fn kthread_create "pri_t pri" "int flags" "struct cpu_info *ci" \
+"void (*func)(void *)" "void *arg" "lwp_t **newlp" "const char *fmt" "..."
+.Ft void
+.Fn kthread_exit "int ecode"
+.Ft int
+.Fn kthread_join "lwp_t *l"
+.Ft int
+.Fn kthread_fpu_enter
+.Ft void
+.Fn kthread_fpu_exit "int s"
+.Sh DESCRIPTION
+Kernel threads are light-weight processes which execute entirely
+within the kernel.
+.Pp
+Any process can request the creation of a new kernel thread.
+Kernel threads are not swapped out during memory congestion.
+The VM space and limits are shared with proc0 (usually swapper).
+.Pp
+If the machine has any per-CPU floating-point units or SIMD vector
+units that are normally available to user threads, they can be used by
+kthreads between
+.Fn kthread_fpu_enter
+and
+.Fn kthread_fpu_exit .
+.Sh FUNCTIONS
+.Bl -tag -width compact
+.It Fn kthread_create "pri" "flags" "ci" "func" "arg" "newlp" "fmt" "..."
+Create a kernel thread.
+The arguments are as follows.
+.Bl -tag -width compact
+.It Fa pri
+Priority level for the thread.
+If no priority level is desired specify
+.Dv PRI_NONE ,
+causing
+.Fn kthread_create
+to select the default priority level.
+.It Fa flags
+Flags that can be logically ORed together to alter the thread's behaviour.
+.It Fa ci
+If
+.No non- Ns Dv NULL ,
+the thread will be created bound to the CPU specified by
+.Fa ci ,
+meaning that it will only ever execute on that CPU.
+By default, the threads are free to execute on any CPU in the system.
+.It Fa func
+A function to be called when the thread begins executing.
+This function must not return.
+If the thread runs to completion, it must call
+.Fn kthread_exit
+to properly terminate itself.
+.It Fa arg
+An argument to be passed to
+.Fn func .
+May be
+.Dv NULL
+if not required.
+.It Fa newlp
+A pointer to receive the new LWP structure for the kernel thread.
+May be
+.Dv NULL ,
+unless
+.Dv KTHREAD_MUSTJOIN
+is specified in
+.Fa flags .
+.It Fa fmt
+A string containing format information used to display the kernel
+thread name.
+Must not be
+.Dv NULL .
+.El
+.Pp
+The following
+.Va flags
+are defined.
+.Bl -tag -width KTHREAD_MUSTJOIN
+.It Dv KTHREAD_IDLE
+Causes the thread to be created in the
+.Dv LSIDL
+(idle) state.
+By default, the threads are created in the
+.Dv LSRUN
+(runnable) state, meaning they will begin execution shortly after creation.
+.It Dv KTHREAD_MPSAFE
+Specifies that the thread does its own locking and so is multiprocessor safe.
+If not specified, the global kernel lock will be held whenever the thread is
+running (unless explicitly dropped by the thread).
+.It Dv KTHREAD_INTR
+Specifies that the thread services device interrupts.
+This flag is intended for kernel internal use and should not normally be
+specified.
+.It Dv KTHREAD_TS
+Causes the kthread to be created in the
+.Dv SCHED_OTHER
+class (timeshared).
+The thread's priority will be dynamically adjusted by the scheduler.
+Increased activity by the kthread will cause its priority to fall;
+decreased activity will cause its priority to rise.
+By default, kthreads are created in the
+.Dv SCHED_RR
+class, with a fixed
+priority specified by
+.Ar pri .
+Threads in the
+.Dv SCHED_RR
+class do not have their priority dynamically
+adjusted by the scheduler.
+.It Dv KTHREAD_MUSTJOIN
+Indicates that created kthread must be joined.
+In such case
+.Fn kthread_exit
+will wait until
+.Fn kthread_join
+will be called.
+.El
+.It Fn kthread_exit "ecode"
+Exit from a kernel thread.
+Must only be called by a kernel thread.
+.It Fn kthread_join "l"
+Suspend execution of calling thread until the target kthread terminates.
+Conceptually the function can be compared to the user space
+.Xr pthread_join 3 ,
+however it must be called only once for kernel thread which was
+created using the
+.Dv KTHREAD_MUSTJOIN
+flag and would wait on
+.Fa kthread_exit .
+.It Fn kthread_fpu_enter
+Allow the current kthread to use any machine-dependent per-CPU
+floating-point units or SIMD vector units normally available to user
+threads.
+Returns a cookie that must be passed to
+.Fn kthread_fpu_exit
+when done.
+.Pp
+Matching pairs of
+.Fn kthread_fpu_enter
+and
+.Fn kthread_fpu_exit
+may be nested.
+.It Fn kthread_fpu_exit "s"
+Restore the current kthread's access to machine-dependent per-CPU
+floating-point units or SIMD vector units to what it was before the
+call to
+.Fn kthread_fpu_enter
+that returned
+.Fa s .
+.Pp
+On the last
+.Fn kthread_fpu_exit ,
+zero all the units' registers to avoid leaking secrets \(em such units
+are often used for cryptography.
+.El
+.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;
+or the limit
+.Dv RLIMIT_NPROC
+on the total number of processes under execution by this
+user id would be exceeded.
+.El
+.Sh CODE REFERENCES
+The kthread framework itself is implemented within the file
+.Pa sys/kern/kern_kthread.c .
+Data structures and function prototypes for the framework are located in
+.Pa sys/sys/kthread.h .
+.Sh SEE ALSO
+.Xr condvar 9 ,
+.Xr driver 9 ,
+.Xr softint 9 ,
+.Xr workqueue 9
+.Sh HISTORY
+The kthread framework appeared in
+.Nx 1.4 .