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Commit 2a1dc509 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
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vmscan: protect zone rotation stats by lru lock 



The zone's rotation statistics must not be accessed without the
corresponding LRU lock held.  Fix an unprotected write in
shrink_active_list().

Acked-by: default avatarRik van Riel <riel@redhat.com>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarJohannes Weiner <hannes@saeurebad.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 33b07db9

mm/vmscan.c

+1 −1
Original line number Diff line number Diff line
@@ -1248,6 +1248,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, 
		list_add(&page->lru, &l_inactive);

	}



	spin_lock_irq(&zone->lru_lock);

	/*

	 * Count referenced pages from currently used mappings as

	 * rotated, even though they are moved to the inactive list.
@@ -1263,7 +1264,6 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, 


	pgmoved = 0;

	lru = LRU_BASE + file * LRU_FILE;

	spin_lock_irq(&zone->lru_lock);

	while (!list_empty(&l_inactive)) {

		page = lru_to_page(&l_inactive);

		prefetchw_prev_lru_page(page, &l_inactive, flags);