Re: [PATCH 2/3] add dev_to_node()

[Ravikiran G Thirumalai <kiran@scalex86.org>]

On Sun, Nov 05, 2006 at 12:53:23AM +0100, Christoph Hellwig wrote:
> On Sat, Nov 04, 2006 at 06:06:48PM -0500, Dave Jones wrote:
> > On Sat, Nov 04, 2006 at 11:56:29PM +0100, Christoph Hellwig wrote:
> > 
> > This will break the compile for !NUMA if someone ends up doing a bisect
> > and lands here as a bisect point.
> > 
> > You introduce this nice wrapper..
> 
> The dev_to_node wrapper is not enough as we can't assign to (-1) for
> the non-NUMA case.  So I added a second macro, set_dev_node for that.
> 
> The patch below compiles and works on numa and non-NUMA platforms.
> 
> 

Hi Christoph,
dev_to_node does not work as expected on x86_64 (and i386).  This is because
node value returned by pcibus_to_node is initialized after a struct device
is created with current x86_64 code.

We need the node value initialized before the call to pci_scan_bus_parented,
as the generic devices are allocated and initialized
off pci_scan_child_bus, which gets called from pci_scan_bus_parented
The following patch does that using "pci_sysdata" introduced by the PCI
domain patches in -mm.

Signed-off-by: Alok N Kataria <alok.kataria@calsoftinc.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>

Index: linux-2.6.19-rc4mm2/arch/i386/pci/acpi.c
===================================================================
--- linux-2.6.19-rc4mm2.orig/arch/i386/pci/acpi.c	2006-11-06 11:03:50.000000000 -0800
+++ linux-2.6.19-rc4mm2/arch/i386/pci/acpi.c	2006-11-06 22:04:14.000000000 -0800
@@ -9,6 +9,7 @@ struct pci_bus * __devinit pci_acpi_scan
 {
 	struct pci_bus *bus;
 	struct pci_sysdata *sd;
+	int pxm;
 
 	/* Allocate per-root-bus (not per bus) arch-specific data.
 	 * TODO: leak; this memory is never freed.
@@ -30,15 +31,21 @@ struct pci_bus * __devinit pci_acpi_scan
 	}
 #endif /* CONFIG_PCI_DOMAINS */
 
+	sd->node = -1;
+
+	pxm = acpi_get_pxm(device->handle);
+#ifdef CONFIG_ACPI_NUMA
+	if (pxm >= 0)
+		sd->node = pxm_to_node(pxm);
+#endif
+
 	bus = pci_scan_bus_parented(NULL, busnum, &pci_root_ops, sd);
 	if (!bus)
 		kfree(sd);
 
 #ifdef CONFIG_ACPI_NUMA
 	if (bus != NULL) {
-		int pxm = acpi_get_pxm(device->handle);
 		if (pxm >= 0) {
-			sd->node = pxm_to_node(pxm);
 			printk("bus %d -> pxm %d -> node %d\n",
 				busnum, pxm, sd->node);
 		}