On Thu, 2 Nov 2006, Horms wrote:
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?
It's a bit unlikely it's the correct fix. As you can see, the add_active_range() is already able to merge contiguous ranges. If the calls imply there is a one page hole, then there is a one page hole. If the caller is wrong and there isn't a one-page hole, then fix the caller walking the map. Power for example currently merges large numbers of adjacent regions that are registered separetly.
--
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) *
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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