Re: 05e0caad3b7bd0d0fbeff980bca22f186241a501 breaks ia64 kdump

[Horms <horms@verge.net.au>]

On Wed, Nov 01, 2006 at 09:38:38AM +0000, Mel Gorman wrote:
> 
> Plan C
> 
> Call add_active_ranges() for the the PFN ranges initmem reside in.
> Look at free_initmem() to see how to get the virtual address of the
> range is found and make the appropriate conversion. A variation is to
> call add_active_ranges() for the PFN range the whole kernel resides in
> if you have that information for the crash kernel.

I've made a version of this approach that seems to work.
I had to update add_active_range so that it merges
ranges that are not overlapping, but do create a continous range.
Is this a correct thing to do?

-- 
Horms
  H: http://www.vergenet.net/~horms/
  W: http://www.valinux.co.jp/en/

Index: linux-2.6/mm/page_alloc.c
=================================--- linux-2.6.orig/mm/page_alloc.c	2006-11-02 16:17:17.000000000 +0900
+++ linux-2.6/mm/page_alloc.c	2006-11-02 16:17:22.000000000 +0900
@@ -2407,7 +2407,7 @@
 			return;
 
 		/* Merge forward if suitable */
-		if (start_pfn <= early_node_map[i].end_pfn &&
+		if (start_pfn <= early_node_map[i].end_pfn + 1 &&
 				end_pfn > early_node_map[i].end_pfn) {
 			early_node_map[i].end_pfn = end_pfn;
 			return;
@@ -2415,7 +2415,7 @@
 
 		/* Merge backward if suitable */
 		if (start_pfn < early_node_map[i].end_pfn &&
-				end_pfn >= early_node_map[i].start_pfn) {
+				end_pfn + 1 >= early_node_map[i].start_pfn) {
 			early_node_map[i].start_pfn = start_pfn;
 			return;
 		}
Index: linux-2.6/arch/ia64/mm/discontig.c
=================================--- linux-2.6.orig/arch/ia64/mm/discontig.c	2006-11-02 16:17:59.000000000 +0900
+++ linux-2.6/arch/ia64/mm/discontig.c	2006-11-02 16:18:03.000000000 +0900
@@ -689,6 +689,8 @@
 	arch_sparse_init();
 
 	efi_memmap_walk(filter_rsvd_memory, count_node_pages);
+	add_active_range(0, ia64_tpa(_text) >> PAGE_SHIFT,
+	                 (ia64_tpa(_end) -1 ) >> PAGE_SHIFT);
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
 	vmalloc_end -= PAGE_ALIGN(ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) *