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Commit 08fc468f authored by KOSAKI Motohiro's avatar KOSAKI Motohiro Committed by Linus Torvalds
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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: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
Reviewed-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Reviewed-by: default avatarMinchan Kim <minchan.kim@gmail.com>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 47185052

mm/vmscan.c

+11 −6
Original line number Original line Diff line number Diff line
@@ -1051,7 +1051,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, 




			/* Check that we have not crossed a zone boundary. */

			/* Check that we have not crossed a zone boundary. */

			if (unlikely(page_zone_id(cursor_page) != zone_id))

			if (unlikely(page_zone_id(cursor_page) != zone_id))

				continue;

				break;





			/*

			/*

			 * If we don't have enough swap space, reclaiming of

			 * If we don't have enough swap space, reclaiming of
@@ -1060,7 +1060,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, 
			 */

			 */

			if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&

			if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&

			    !PageSwapCache(cursor_page))

			    !PageSwapCache(cursor_page))

				continue;

				break;





			if (__isolate_lru_page(cursor_page, mode, file) == 0) {

			if (__isolate_lru_page(cursor_page, mode, file) == 0) {

				list_move(&cursor_page->lru, dst);

				list_move(&cursor_page->lru, dst);
@@ -1071,11 +1071,16 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, 
					nr_lumpy_dirty++;

					nr_lumpy_dirty++;

				scan++;

				scan++;

			} else {

			} else {

				if (mode == ISOLATE_BOTH &&

				/* the page is freed already. */

						page_count(cursor_page))

				if (!page_count(cursor_page))

					nr_lumpy_failed++;

					continue;

				break;

			}

			}

		}

		}



		/* If we break out of the loop above, lumpy reclaim failed */

		if (pfn < end_pfn)

			nr_lumpy_failed++;

	}

	}





	*scanned = scan;

	*scanned = scan;