From 86051ca5eaf5e560113ec7673462804c54284456 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 29 Apr 2008 00:58:21 -0700 Subject: [PATCH] mm: fix usemap initialization usemap must be initialized only when pfn is within zone. If not, it corrupts memory. And this patch also reduces the number of calls to set_pageblock_migratetype() from (pfn & (pageblock_nr_pages -1) to !(pfn & (pageblock_nr_pages-1) it should be called once per pageblock. Signed-off-by: KAMEZAWA Hiroyuki Acked-by: Mel Gorman Cc: Hugh Dickins Cc: Shi Weihua Cc: Balbir Singh Cc: Pavel Emelyanov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d1cf4f05dcda..88eb59dd7ac6 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2524,7 +2524,9 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, struct page *page; unsigned long end_pfn = start_pfn + size; unsigned long pfn; + struct zone *z; + z = &NODE_DATA(nid)->node_zones[zone]; for (pfn = start_pfn; pfn < end_pfn; pfn++) { /* * There can be holes in boot-time mem_map[]s @@ -2542,7 +2544,6 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, init_page_count(page); reset_page_mapcount(page); SetPageReserved(page); - /* * Mark the block movable so that blocks are reserved for * movable at startup. This will force kernel allocations @@ -2551,8 +2552,15 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, * kernel allocations are made. Later some blocks near * the start are marked MIGRATE_RESERVE by * setup_zone_migrate_reserve() + * + * bitmap is created for zone's valid pfn range. but memmap + * can be created for invalid pages (for alignment) + * check here not to call set_pageblock_migratetype() against + * pfn out of zone. */ - if ((pfn & (pageblock_nr_pages-1))) + if ((z->zone_start_pfn <= pfn) + && (pfn < z->zone_start_pfn + z->spanned_pages) + && !(pfn & (pageblock_nr_pages - 1))) set_pageblock_migratetype(page, MIGRATE_MOVABLE); INIT_LIST_HEAD(&page->lru); @@ -4464,6 +4472,8 @@ void set_pageblock_flags_group(struct page *page, unsigned long flags, pfn = page_to_pfn(page); bitmap = get_pageblock_bitmap(zone, pfn); bitidx = pfn_to_bitidx(zone, pfn); + VM_BUG_ON(pfn < zone->zone_start_pfn); + VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) if (flags & value) -- 2.20.1