Update to match cpu_switchto reality.

2 files changed, 15 insertions, 42 deletions

diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index 65e2cc13ff8..cb616611478 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.131 2007/10/02 17:29:44 cnst Exp $
+#	$OpenBSD: Makefile,v 1.132 2007/10/10 16:21:29 art Exp $
 #	$NetBSD: Makefile,v 1.4 1996/01/09 03:23:01 thorpej Exp $
 
 #	Makefile for section 9 (kernel function and variable) manual pages.
@@ -112,7 +112,7 @@ MLINKS+=crypto.9 crypto_register.9 \
 	crypto.9 crypto_kdispatch.9 \
 	crypto.9 crypto_getreq.9 \
 	crypto.9 crypto_freereq.9
-MLINKS+=ctxsw.9 cpu_switch.9 ctxsw.9 mi_switch.9
+MLINKS+=ctxsw.9 cpu_switchto.9 ctxsw.9 mi_switch.9
 MLINKS+=disk.9 disk_init.9 disk.9 disk_attach.9 disk.9 disk_detatch.9 \
 	disk.9 disk_busy.9 disk.9 disk_unbusy.9
 MLINKS+=disklabel.9 readdisklabel.9 disklabel.9 writedisklabel.9 \
diff --git a/share/man/man9/ctxsw.9 b/share/man/man9/ctxsw.9
index 5e48791e9e0..acbaad0a17e 100644
--- a/share/man/man9/ctxsw.9
+++ b/share/man/man9/ctxsw.9
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ctxsw.9,v 1.12 2007/09/14 16:16:08 mk Exp $
+.\"	$OpenBSD: ctxsw.9,v 1.13 2007/10/10 16:21:29 art Exp $
 .\"	$NetBSD: ctxsw.9,v 1.9 1999/03/06 22:09:29 mycroft Exp $
 .\"
 .\" Copyright (c) 1996 The NetBSD Foundation, Inc.
@@ -35,12 +35,12 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: September 14 2007 $
+.Dd $Mdocdate: October 10 2007 $
 .Dt CTXSW 9
 .Os
 .Sh NAME
 .Nm mi_switch ,
-.Nm cpu_switch
+.Nm cpu_switchto
 .Nd switch to another process context
 .Sh SYNOPSIS
 .Fd #include <sys/param.h>
@@ -48,7 +48,7 @@
 .Ft void
 .Fn mi_switch "void"
 .Ft void
-.Fn cpu_switch "void"
+.Fn cpu_switchto "struct proc *old" "struct proc *new"
 .Sh DESCRIPTION
 The
 .Fn mi_switch
@@ -96,49 +96,22 @@ For a process which accumulated longer than 10 minutes of
 CPU time, its nice level is raised to 4.
 After these administrative tasks are done,
 .Fn mi_switch
-hands over control to the machine dependent routine
-.Fn cpu_switch "void" ,
+chooses the next process to run and hands over control to the machine
+dependent routine
+.Fn cpu_switchto ,
 which will perform the actual process context switch.
 .Pp
-.Fn cpu_switch
-will make a choice amongst the processes which are ready to run from a
-priority queue data-structure.
-The priority queue consists of an array
-.Va qs[NQS]
-of queue header structures each of which identifies a list of runnable
-processes of equal priority
-.Pq see Aq Pa sys/proc.h .
-A single word
-.Va whichqs
-containing a bit mask identifying non-empty queues assists in selecting
-a process quickly.
-.Fn cpu_switch
-must remove the first process from the list on the queue
-with the highest priority
-(lower indices in
-.Va qs
-indicate higher priority),
-and assign the address of its process structure to the global variable
-.Va curproc .
-If no processes are available on the run queues,
-.Fn cpu_switch
-shall go into an
-.Dq idle
-loop.
-The idle loop must allow interrupts to be taken that will eventually cause
-processes to appear again on the run queues.
-The variable
-.Va curproc
-should be
+.Fn cpu_switchto
+will save the context of the old process and switch to the new one.
+A special case is when the old process is
 .Dv NULL
-while
-.Fn cpu_switch
-waits for this to happen.
+which means that the old process has exited and doesn't need to be
+saved.
 .Pp
 Note that
 .Fn mi_switch
 and thus
-.Fn cpu_switch
+.Fn cpu_switchto
 should be called at
 .Xr splhigh 9 .
 .Sh SEE ALSO