Commit d100313f authored Oct 16, 2007 by Mel Gorman Committed by Linus Torvalds Oct 16, 2007

Fix calculation in move_freepages_block for counting pages



move_freepages_block() returns the number of blocks moved.  This value is used
to determine if a block of pages should be stolen for the exclusive use of a
migrate type or not.  However, the value returned is being used correctly.
This patch fixes the calculation to return the number of base pages that have
been moved.

This should be considered a fix to the patch
move-free-pages-between-lists-on-steal.patch

Credit to Andy Whitcroft for spotting the problem.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 64c5e135

mm/page_alloc.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -718,7 +718,7 @@ int move_freepages(struct zone *zone,
		{
		struct page *page;
		unsigned long order;
		int blocks_moved = 0;
		int pages_moved = 0;

		#ifndef CONFIG_HOLES_IN_ZONE
		/*
		@@ -747,10 +747,10 @@ int move_freepages(struct zone *zone,
		list_add(&page->lru,
		&zone->free_area[order].free_list[migratetype]);
		page += 1 << order;
		blocks_moved++;
		pages_moved += 1 << order;
		}

		return blocks_moved;
		return pages_moved;
		}

		int move_freepages_block(struct zone zone, struct page page, int migratetype)
		@@ -833,7 +833,7 @@ static struct page __rmqueue_fallback(struct zone zone, int order,
		start_migratetype);

		/* Claim the whole block if over half of it is free */
		if ((pages << current_order) >= (1 << (MAX_ORDER-2)))
		if (pages >= (1 << (MAX_ORDER-2)))
		set_pageblock_migratetype(page,
		start_migratetype);

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