From 76cdd58e558669366adfaded436fda01b30cce3e Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 14 May 2008 16:05:52 -0700 Subject: memory_hotplug: always initialize pageblock bitmap Trying to online a new memory section that was added via memory hotplug sometimes results in crashes when the new pages are added via __free_page. Reason for that is that the pageblock bitmap isn't initialized and hence contains random stuff. That means that get_pageblock_migratetype() returns also random stuff and therefore list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); in __free_one_page() tries to do a list_add to something that isn't even necessarily a list. This happens since 86051ca5eaf5e560113ec7673462804c54284456 ("mm: fix usemap initialization") which makes sure that the pageblock bitmap gets only initialized for pages present in a zone. Unfortunately for hot-added memory the zones "grow" after the memmap and the pageblock memmap have been initialized. Which means that the new pages have an unitialized bitmap. To solve this the calls to grow_zone_span() and grow_pgdat_span() are moved to __add_zone() just before the initialization happens. The patch also moves the two functions since __add_zone() is the only caller and I didn't want to add a forward declaration. Signed-off-by: Heiko Carstens Cc: Andy Whitcroft Cc: Dave Hansen Cc: Gerald Schaefer Cc: KAMEZAWA Hiroyuki Cc: Yasunori Goto Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index bdd5c432c426..63835579323a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2862,8 +2862,6 @@ __meminit int init_currently_empty_zone(struct zone *zone, zone->zone_start_pfn = zone_start_pfn; - memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); - zone_init_free_lists(zone); return 0; @@ -3433,6 +3431,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, ret = init_currently_empty_zone(zone, zone_start_pfn, size, MEMMAP_EARLY); BUG_ON(ret); + memmap_init(size, nid, j, zone_start_pfn); zone_start_pfn += size; } } -- cgit v1.2.2