The new dev sysctl tree

[Maxime Henrion]

	Hi all,


Dag-Erling recently committed some code that makes it extremely easy
and convenient to have per-devices sysctl.  I changed the fxp(4)
driver to use this new framework for its sysctls, which allows to
remove a bit of code from this driver.

However, there is a significant drawback.  For instance, what used to
be "hw.fxp0.int_delay" is now called (on my box) :
"dev.root0.nexus0.acpi0.pcib0.pci0.fxp0.int_delay".  Obviously, this
is really too long to be convenient to use.  Furthermore, the name of
this sysctl is not unique anymore.  This is particularly annoying in
some cases.  For instance, if someone needs to boot without acpi while
he's using it the rest of the time, the sysctl won't be named the same.

So I made a patch to flatten this sysctl tree.  This doesn't cause any
conflict since attached drivers' names are unique.  As a consequence,
we lose the hierarchy information from the sysctl tree, however I
believe this isn't a problem since we can get this information with
devinfo(8) already.  If for some reason, we really need the hierarchy
information in this sysctl tree, I can easily add a .parent sysctl to
each device node.

I'm attaching the patch that flattens the sysctl tree to this mail.

Opinions are of course welcome, but please, this isn't a call for yet
another bikeshed of hell, so keep to the point.

Cheers,
Maxime
-------------- next part --------------
Index: subr_bus.c
===================================================================
RCS file: /space2/ncvs/src/sys/kern/subr_bus.c,v
retrieving revision 1.146
diff -u -p -r1.146 subr_bus.c
--- subr_bus.c	26 May 2004 16:36:32 -0000	1.146
+++ subr_bus.c	31 May 2004 23:58:00 -0000
@@ -241,22 +241,13 @@ device_sysctl_handler(SYSCTL_HANDLER_ARG
 static void
 device_sysctl_init(device_t dev)
 {
-	struct sysctl_oid_list *parent_node;
 
-	if (dev->parent) {
-		if (dev->parent->sysctl_tree == NULL)
-			device_sysctl_init(dev->parent);
-		parent_node = SYSCTL_CHILDREN(dev->parent->sysctl_tree);
-	} else {
-		parent_node = SYSCTL_STATIC_CHILDREN(_dev);
-	}
-	if (dev->sysctl_tree != NULL) {
-		sysctl_move_oid(dev->sysctl_tree, parent_node);
+	if (dev->sysctl_tree != NULL)
 		return;
-	}
 	sysctl_ctx_init(&dev->sysctl_ctx);
-	dev->sysctl_tree = SYSCTL_ADD_NODE(&dev->sysctl_ctx, parent_node,
-	    OID_AUTO, dev->nameunit, CTLFLAG_RD, 0, "");
+	dev->sysctl_tree = SYSCTL_ADD_NODE(&dev->sysctl_ctx,
+	    SYSCTL_STATIC_CHILDREN(_dev), OID_AUTO, dev->nameunit,
+	    CTLFLAG_RD, 0, "");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%class", CTLFLAG_RD,
 	    dev, DEVICE_SYSCTL_CLASS, device_sysctl_handler, "A",