Messages in this thread Patch in this message | | | From | Johannes Weiner <> | Subject | [patch v2] vmscan: protect zone rotation stats by lru lock | Date | Mon, 01 Dec 2008 03:00:35 +0100 |
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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> --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Applies to your tree, Linus, and should probably go into .28.
--- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1243,32 +1243,32 @@ static void shrink_active_list(unsigned /* page_referenced clears PageReferenced */ if (page_mapping_inuse(page) && page_referenced(page, 0, sc->mem_cgroup)) pgmoved++; 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. * This helps balance scan pressure between file and anonymous * pages in get_scan_ratio. */ zone->recent_rotated[!!file] += pgmoved; /* * Move the pages to the [file or anon] inactive list. */ pagevec_init(&pvec, 1); 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); VM_BUG_ON(PageLRU(page)); SetPageLRU(page); VM_BUG_ON(!PageActive(page)); ClearPageActive(page);
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