From fb37fdfab5a723c289f1be430cf28ba8dedb48a7 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 16 Jun 2009 15:31:40 -0700 Subject: [PATCH] vmscan: low order lumpy reclaim also should use PAGEOUT_IO_SYNC Commit 68a36317e46b1e149e792918ea09dcf9b06b050e ("more aggressively use lumpy reclaim") increased how aggressive lumpy reclaim was by isolating both active and inactive pages for asynchronous lumpy reclaim on costly-high-order pages and for cheap-high-order when memory pressure is high. However, if the system is under heavy pressure and there are dirty pages, asynchronous IO may not be sufficient to reclaim a suitable page in time. This patch causes the caller to enter synchronous lumpy reclaim for costly-high-order pages and for cheap-high-order pages when under memory pressure. Minchan.kim@gmail.com said: Andy added synchronous lumpy reclaim with 4ad510b7efc4fa7085959a8cffc3fb8111011210. At that time, lumpy reclaim is not agressive. His intension is just for high-order users.(above PAGE_ALLOC_COSTLY_ORDER). After some time, Rik added aggressive lumpy reclaim with 68a36317e46b1e149e792918ea09dcf9b06b050e. His intention was to do lumpy reclaim when high-order users and trouble getting a small set of contiguous pages. So we also have to add synchronous pageout for small set of contiguous pages. Cc: Lee Schermerhorn Cc: Andy Whitcroft Acked-by: Peter Zijlstra Cc: Rik van Riel Signed-off-by: KOSAKI Motohiro Reviewed-by: Minchan Kim Reviewed-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 95c08a8cc2ba4..a6b7d14812e6e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1061,6 +1061,19 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, unsigned long nr_scanned = 0; unsigned long nr_reclaimed = 0; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); + int lumpy_reclaim = 0; + + /* + * If we need a large contiguous chunk of memory, or have + * trouble getting a small set of contiguous pages, we + * will reclaim both active and inactive pages. + * + * We use the same threshold as pageout congestion_wait below. + */ + if (sc->order > PAGE_ALLOC_COSTLY_ORDER) + lumpy_reclaim = 1; + else if (sc->order && priority < DEF_PRIORITY - 2) + lumpy_reclaim = 1; pagevec_init(&pvec, 1); @@ -1073,19 +1086,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, unsigned long nr_freed; unsigned long nr_active; unsigned int count[NR_LRU_LISTS] = { 0, }; - int mode = ISOLATE_INACTIVE; - - /* - * If we need a large contiguous chunk of memory, or have - * trouble getting a small set of contiguous pages, we - * will reclaim both active and inactive pages. - * - * We use the same threshold as pageout congestion_wait below. - */ - if (sc->order > PAGE_ALLOC_COSTLY_ORDER) - mode = ISOLATE_BOTH; - else if (sc->order && priority < DEF_PRIORITY - 2) - mode = ISOLATE_BOTH; + int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE; nr_taken = sc->isolate_pages(sc->swap_cluster_max, &page_list, &nr_scan, sc->order, mode, @@ -1122,7 +1123,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, * but that should be acceptable to the caller */ if (nr_freed < nr_taken && !current_is_kswapd() && - sc->order > PAGE_ALLOC_COSTLY_ORDER) { + lumpy_reclaim) { congestion_wait(WRITE, HZ/10); /* -- 2.39.5