From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: [patch v2] vmscan: protect zone rotation stats by lru lock Message-Id: Date: Mon, 01 Dec 2008 03:00:35 +0100 Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: Andrew Morton , Rik van Riel , KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: 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 Reviewed-by: KOSAKI Motohiro Signed-off-by: Johannes Weiner --- 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); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org