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: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2008-12-01 03:00:35 +01:00 committed by Linus Torvalds
parent 33b07db9f3
commit 2a1dc50974

View file

@ -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);