Commit c277331d authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

mm: page_alloc: clear PG_locked before checking flags on free 



da456f14 "page allocator: do not disable interrupts in free_page_mlock()" moved
the PG_mlocked clearing after the flag sanity checking which makes mlocked
pages always trigger 'bad page'.  Fix this by clearing the bit up front.

Reported--and-debugged-by: default avatarPeter Chubb <peter.chubb@nicta.com.au>
Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMel Gorman <mel@csn.ul.ie>
Tested-by: default avatarMaxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9063c61f

mm/page_alloc.c

+4 −5
Original line number Diff line number Diff line
@@ -488,7 +488,6 @@ static inline void __free_one_page(struct page *page, 
 */

static inline void free_page_mlock(struct page *page)

{

	__ClearPageMlocked(page);

	__dec_zone_page_state(page, NR_MLOCK);

	__count_vm_event(UNEVICTABLE_MLOCKFREED);

}
@@ -558,7 +557,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) 
	unsigned long flags;

	int i;

	int bad = 0;

	int clearMlocked = PageMlocked(page);

	int wasMlocked = TestClearPageMlocked(page);



	kmemcheck_free_shadow(page, order);
@@ -576,7 +575,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) 
	kernel_map_pages(page, 1 << order, 0);



	local_irq_save(flags);

	if (unlikely(clearMlocked))

	if (unlikely(wasMlocked))

		free_page_mlock(page);

	__count_vm_events(PGFREE, 1 << order);

	free_one_page(page_zone(page), page, order,
@@ -1022,7 +1021,7 @@ static void free_hot_cold_page(struct page *page, int cold) 
	struct zone *zone = page_zone(page);

	struct per_cpu_pages *pcp;

	unsigned long flags;

	int clearMlocked = PageMlocked(page);

	int wasMlocked = TestClearPageMlocked(page);



	kmemcheck_free_shadow(page, 0);
@@ -1041,7 +1040,7 @@ static void free_hot_cold_page(struct page *page, int cold) 
	pcp = &zone_pcp(zone, get_cpu())->pcp;

	set_page_private(page, get_pageblock_migratetype(page));

	local_irq_save(flags);

	if (unlikely(clearMlocked))

	if (unlikely(wasMlocked))

		free_page_mlock(page);

	__count_vm_event(PGFREE);

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