Merge commit 'v3.2-rc6' into perf/core

Merge reason: Update with the latest fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9dd443d89d8b..2b8ba3aebf6e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -356,8 +356,8 @@ void prep_compound_page(struct page *page, unsigned long order)
 	__SetPageHead(page);
 	for (i = 1; i < nr_pages; i++) {
 		struct page *p = page + i;
-
 		__SetPageTail(p);
+		set_page_count(p, 0);
 		p->first_page = page;
 	}
 }
@@ -3377,9 +3377,15 @@ static void setup_zone_migrate_reserve(struct zone *zone)
 	unsigned long block_migratetype;
 	int reserve;
 
-	/* Get the start pfn, end pfn and the number of blocks to reserve */
+	/*
+	 * Get the start pfn, end pfn and the number of blocks to reserve
+	 * We have to be careful to be aligned to pageblock_nr_pages to
+	 * make sure that we always check pfn_valid for the first page in
+	 * the block.
+	 */
 	start_pfn = zone->zone_start_pfn;
 	end_pfn = start_pfn + zone->spanned_pages;
+	start_pfn = roundup(start_pfn, pageblock_nr_pages);
 	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
 							pageblock_order;