Add a prioritization field to the devstat_add_entry() call so that

peripheral drivers can determine where in the devstat(9) list they are
inserted.

This requires recompilation of libdevstat, systat, vmstat, rpc.rstatd, and
any ports that depend on the devstat code, since the size of the devstat
structure has changed.  The devstat version number has been incremented as
well to reflect the change.

This sorts devices in the devstat list in "more interesting" to "less
interesting" order.  So, for instance, da devices are now more important
than floppy drives, and so will appear before floppy drives in the default
output from systat, iostat, vmstat, etc.

The order of devices is, for now, kept in a central table in devicestat.h.
If individual drivers were able to make a meaningful decision on what
priority they should be at attach time, we could consider splitting the
priority information out into the various drivers.  For now, though, they
have no way of knowing that, so it's easier to put them in an easy to find
table.

Also, move the checkversion() call in vmstat(8) to a more logical place.

Thanks to Bruce and David O'Brien for suggestions, for reviewing this, and
for putting up with the long time it has taken me to commit it.  Bruce did
object somewhat to the central priority table (he would rather the
priorities be distributed in each driver), so his objection is duly noted
here.

Reviewed by:	bde, obrien

1 files changed, 39 insertions, 3 deletions

diff --git a/share/man/man9/devstat.9 b/share/man/man9/devstat.9
index 25a3088..779d9c9 100644
--- a/share/man/man9/devstat.9
+++ b/share/man/man9/devstat.9
@@ -1,5 +1,5 @@
 .\"
-.\" Copyright (c) 1998 Kenneth D. Merry.
+.\" Copyright (c) 1998, 1999 Kenneth D. Merry.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$Id$
+.\"	$Id: devstat.9,v 1.1 1998/09/15 06:49:18 gibbs Exp $
 .\"
 .Dd May 22, 1998
 .Dt DEVSTAT 9
@@ -43,6 +43,7 @@
 .Fa "u_int32_t block_size"
 .Fa "devstat_support_flags flags"
 .Fa "devstat_type_flags device_type"
+.Fa "devstat_priority priority"
 .Fc
 .Ft void
 .Fn devstat_remove_entry "struct devstat *ds"
@@ -56,7 +57,7 @@
 .Fa "devstat_trans_flags flags"
 .Fc
 .Sh DESCRIPTION
-The devstat subsystem is basically an interface for recording device
+The devstat subsystem is an interface for recording device
 statistics, as its name implies.  The idea is to keep reasonably detailed
 statistics while utilizing a minimum amount of CPU time to record them.
 Thus, no statistical calculations are actually performed in the kernel
@@ -94,6 +95,13 @@ The device type.  This is broken into three sections:  base device type
 (e.g. direct access, CDROM, sequential access), interface type (IDE, SCSI
 or other) and a passthrough flag to indicate pasthrough devices.  See below
 for a complete list of types.
+.It priority
+The device priority.  The priority is used to determine how devices are
+sorted within 
+.Nm devstat's
+list of devices.  Devices are sorted first by priority (highest to lowest),
+and then by attach order.  See below for a complete list of available
+priorities.
 .El
 .Pp
 .Fn devstat_remove_entry
@@ -219,6 +227,12 @@ This is the device type.  It consists of three parts:  the device type
 (e.g. direct access, CDROM, sequential access, etc.), the interface (IDE,
 SCSI or other) and whether or not the device in question is a passthrough
 driver.  See below for a complete list of device types.
+.It priority
+This is the priority.  This is the first parameter used to determine where
+to insert a device in the
+.Nm devstat
+list.  The second parameter is attach order.  See below for a list of
+available priorities.
 .El
 .Pp
 Each device is given a device type.  Passthrough devices have the same
@@ -259,6 +273,28 @@ typedef enum {
 } devstat_type_flags;
 .Ed
 .Pp
+Devices have a priority associated with them, which controls roughly where
+they are placed in the
+.Nm devstat
+list.  The priorities are as follows:
+.Bd -literal -offset indent
+typedef enum {
+	DEVSTAT_PRIORITY_MIN	= 0x000,
+	DEVSTAT_PRIORITY_OTHER	= 0x020,
+	DEVSTAT_PRIORITY_PASS	= 0x030,
+	DEVSTAT_PRIORITY_FD	= 0x040,
+	DEVSTAT_PRIORITY_WFD	= 0x050,
+	DEVSTAT_PRIORITY_SA	= 0x060,
+	DEVSTAT_PRIORITY_OCD	= 0x070,
+	DEVSTAT_PRIORITY_WCD	= 0x080,
+	DEVSTAT_PRIORITY_CD	= 0x090,
+	DEVSTAT_PRIORITY_WD	= 0x100,
+	DEVSTAT_PRIORITY_DA	= 0x110,
+	DEVSTAT_PRIORITY_CCD	= 0x120,
+	DEVSTAT_PRIORITY_MAX	= 0xfff
+} devstat_priority;
+.Ed
+.Pp
 Each device has associated with it flags to indicate what operations are
 supported or not supported.  The
 .Va devstat_support_flags