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Document the kproc_kthread_add() call

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and fix a small detail of its implementation.
MFC after: 1 week
This commit is contained in:
Julian Elischer 2008-04-29 22:43:15 +00:00
parent a8f7b90ca0
commit c59b9a7659
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=178682
3 changed files with 76 additions and 1 deletions
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58
share/man/man9/kproc.9
View File

@ -57,6 +57,12 @@
.Fn kproc_suspend "struct proc *p" "int timo"
.Ft void
.Fn kproc_suspend_check "struct proc *p"
.Ft int
.Fo kproc_kthread_add
.Fa "void (*func)(void *)" "void *arg"
.Fa "struct proc **procptr" "struct thread **tdptr"
.Fa "int flags" "int pages" "char * procname" "const char *fmt" "..."
.Fc
.Sh DESCRIPTION
The function
.Fn kproc_start
@ -196,6 +202,58 @@ need to be suspended voluntarily during system shutdown so as not to interfere
with system shutdown activities.
The actual suspension of the kernel process is done with
.Fn kproc_suspend .
.Pp
The
.Fn kproc_kthread_add
function is much like the
.Fn kproc_create
function above except that if the kproc already exists,
then only a new thread (see
.Xr kthread 9 )
is created on the existing process.
The
.Fa func
argument specifies the function that the process should execute.
The
.Fa arg
argument is an arbitrary pointer that is passed in as the only argument to
.Fa func
when it is called by the new process.
The
.Fa procptr
pointer points to a
.Vt "struct proc "
pointer that is the location to be updated with the new proc pointer
if a new process is created, or if not
.Dv NULL ,
must contain the process pointer for the already exisiting process.
If this argument points to
.Dv NULL ,
then a new process is created and the field updated.
If not NULL, the
.Fa tdptr
pointer points to a
.Vt "struct thread "
pointer that is the location to be updated with the new thread pointer.
The
.Fa flags
argument specifies a set of flags as described in
.Xr rfork 2 .
The
.Fa pages
argument specifies the size of the new kernel thread's stack in pages.
If 0 is used, the default kernel stack size is allocated.
The procname argument is the name the new process should be given if it needs to be created.
It is
.Em NOT
a printf style format specifier but a simple string.
The rest of the arguments form a
.Xr printf 9
argument list that is used to build the name of the new thread and is stored
in the
.Va td_name
member of the new thread's
.Vt "struct thread" .
.Sh RETURN VALUES
The
.Fn kproc_create ,

16
share/man/man9/kthread.9
View File

@ -57,6 +57,12 @@
.Fn kthread_suspend "struct thread *td" "int timo"
.Ft void
.Fn kthread_suspend_check "struct thread *td"
.Ft int
.Fo kproc_kthread_add
.Fa "void (*func)(void *)" "void *arg"
.Fa "struct proc **procptr" "struct thread **tdptr"
.Fa "int flags" "int pages" "char * procname" "const char *fmt" "..."
.Fc
.Sh DESCRIPTION
The function
.Fn kthread_start
@ -151,6 +157,16 @@ member of the new thread's
.Vt "struct thread" .
.Pp
The
.Fn kproc_kthread_add
function is much like the
.Fn kthread_add
function above except that if the kproc does not already
exist, it is created.
This function is better documented in the
.Xr kproc 9
manual page.
.Pp
The
.Fn kthread_exit
function is used to terminate kernel threads.
It should be called by the main function of the kernel thread rather than

3
sys/kern/kern_kthread.c
View File

@ -403,7 +403,8 @@ kproc_kthread_add(void (*func)(void *), void *arg,
if (error)
return (error);
td = FIRST_THREAD_IN_PROC(*procptr);
*tdptr = td;
if (tdptr)
*tdptr = td;
va_start(ap, fmt);
vsnprintf(td->td_name, sizeof(td->td_name), fmt, ap);
va_end(ap);