[PATCH: 005/012] Memory hotplug for new nodes v.2.(pgdat alloc caller for x86-64)

[PATCH: 005/012] Memory hotplug for new nodes v.2.(pgdat alloc caller for x86-64)

[Yasunori Goto]

This is code for calling pgdat allocation function for x86_64.
Basically it is same with ia64. 

But, decision of ZONE_DMA32 or ZONE_NORMAL is necessary.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>

Index: linux-2.6.15/arch/x86_64/mm/init.c
=================================--- linux-2.6.15.orig/arch/x86_64/mm/init.c	2006-02-16 20:21:29.000000000 +0900
+++ linux-2.6.15/arch/x86_64/mm/init.c	2006-02-16 21:34:29.000000000 +0900
@@ -26,6 +26,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/memory_hotplug.h>
+#include <linux/acpi.h>
 
 #include <asm/processor.h>
 #include <asm/system.h>
@@ -494,12 +495,27 @@
 
 int add_memory(u64 start, u64 size)
 {
-	struct pglist_data *pgdat = NODE_DATA(0);
-	struct zone *zone = pgdat->node_zones + MAX_NR_ZONES-2;
+	struct zone *zone;
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
-	int ret;
+	int ret, node, zone_type, new_pgdat = 0;
 
+	node = acpi_paddr_to_node(start, size);
+
+	if (node < 0)
+		node = 0; /* pxm is undefined in DSDT.
+			     This might be non NUMA case */
+
+	if (!node_online(node)) {
+		ret = new_pgdat_init(node, start_pfn, nr_pages);
+		if (ret)
+			goto error;
+		new_pgdat = 1;
+	}
+
+	zone_type = start_pfn < MAX_DMA32_PFN ?
+		    ZONE_DMA32 : ZONE_NORMAL;
+	zone = NODE_DATA(node)->node_zones + zone_type;
 	ret = __add_pages(zone, start_pfn, nr_pages);
 	if (ret)
 		goto error;
@@ -509,6 +525,9 @@
 	return ret;
 error:
 	printk("%s: Problem encountered in __add_pages!\n", __func__);
+	if (new_pgdat)
+		release_pgdat(NODE_DATA(node));
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(add_memory);

-- 
Yasunori Goto 

Re: [PATCH: 005/012] Memory hotplug for new nodes v.2.(pgdat alloc

[Dave Hansen]

On Fri, 2006-02-17 at 22:29 +0900, Yasunori Goto wrote:
> +       zone_type = start_pfn < MAX_DMA32_PFN ?
> +                   ZONE_DMA32 : ZONE_NORMAL; 

Please change this to something which we can more easily parse, such as
this:

	if (start_pfn < MAX_DMA32_PFN)
		zone_type = ZONE_DMA32;
	else
		zone_type = ZONE_NORMAL;

I think it is worth the extra two lines.

-- Dave