From 344c790e3821dac37eb742ddd0b611a300f78b9a Mon Sep 17 00:00:00 2001 From: Adam Litke Date: Tue, 2 Sep 2008 14:35:38 -0700 Subject: [PATCH] mm: make setup_zone_migrate_reserve() aware of overlapping nodes I have gotten to the root cause of the hugetlb badness I reported back on August 15th. My system has the following memory topology (note the overlapping node): Node 0 Memory: 0x8000000-0x44000000 Node 1 Memory: 0x0-0x8000000 0x44000000-0x80000000 setup_zone_migrate_reserve() scans the address range 0x0-0x8000000 looking for a pageblock to move onto the MIGRATE_RESERVE list. Finding no candidates, it happily continues the scan into 0x8000000-0x44000000. When a pageblock is found, the pages are moved to the MIGRATE_RESERVE list on the wrong zone. Oops. setup_zone_migrate_reserve() should skip pageblocks in overlapping nodes. Signed-off-by: Adam Litke Acked-by: Mel Gorman Cc: Dave Hansen Cc: Nishanth Aravamudan Cc: Andy Whitcroft Cc: [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index af982f7cdb2a..feb791648a1f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -694,6 +694,9 @@ static int move_freepages(struct zone *zone, #endif for (page = start_page; page <= end_page;) { + /* Make sure we are not inadvertently changing nodes */ + VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); + if (!pfn_valid_within(page_to_pfn(page))) { page++; continue; @@ -2516,6 +2519,10 @@ static void setup_zone_migrate_reserve(struct zone *zone) continue; page = pfn_to_page(pfn); + /* Watch out for overlapping nodes */ + if (page_to_nid(page) != zone_to_nid(zone)) + continue; + /* Blocks with reserved pages will never free, skip them. */ if (PageReserved(page)) continue; -- 2.20.1