From 08fc468f4eaf6683bae5bdb94743a09d8630cb80 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 26 Oct 2010 14:21:44 -0700 Subject: vmscan: isolate_lru_pages(): stop neighbour search if neighbour cannot be isolated isolate_lru_pages() does not just isolate LRU tail pages, but also isolates neighbour pages of the eviction page. The neighbour search does not stop even if neighbours cannot be isolated which is excessive as the lumpy reclaim will no longer result in a successful higher order allocation. This patch stops the PFN neighbour pages if an isolation fails and moves on to the next block. Signed-off-by: KOSAKI Motohiro Signed-off-by: Mel Gorman Reviewed-by: Wu Fengguang Reviewed-by: Minchan Kim Reviewed-by: KAMEZAWA Hiroyuki Cc: Johannes Weiner Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'mm') diff --git a/mm/vmscan.c b/mm/vmscan.c index cec8081bbd9..130ad0239f5 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1051,7 +1051,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, /* Check that we have not crossed a zone boundary. */ if (unlikely(page_zone_id(cursor_page) != zone_id)) - continue; + break; /* * If we don't have enough swap space, reclaiming of @@ -1059,8 +1059,8 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, * pointless. */ if (nr_swap_pages <= 0 && PageAnon(cursor_page) && - !PageSwapCache(cursor_page)) - continue; + !PageSwapCache(cursor_page)) + break; if (__isolate_lru_page(cursor_page, mode, file) == 0) { list_move(&cursor_page->lru, dst); @@ -1071,11 +1071,16 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, nr_lumpy_dirty++; scan++; } else { - if (mode == ISOLATE_BOTH && - page_count(cursor_page)) - nr_lumpy_failed++; + /* the page is freed already. */ + if (!page_count(cursor_page)) + continue; + break; } } + + /* If we break out of the loop above, lumpy reclaim failed */ + if (pfn < end_pfn) + nr_lumpy_failed++; } *scanned = scan; -- cgit v1.2.3-18-g5258