Subject: [merged] mm-vmscan-do-not-swap-anon-pages-just-because-freefile-is-low.patch removed from -mm tree
To: hannes@xxxxxxxxxxx,aquini@xxxxxxxxxx,hughd@xxxxxxxxxx,mgorman@xxxxxxx,riel@xxxxxxxxxx,stable@xxxxxxxxxx,suleiman@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Wed, 09 Apr 2014 10:55:29 -0700
The patch titled
Subject: mm: vmscan: do not swap anon pages just because free+file is low
has been removed from the -mm tree. Its filename was
mm-vmscan-do-not-swap-anon-pages-just-because-freefile-is-low.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: vmscan: do not swap anon pages just because free+file is low
Page reclaim force-scans / swaps anonymous pages when file cache drops
below the high watermark of a zone in order to prevent what little cache
remains from thrashing.
However, on bigger machines the high watermark value can be quite large
and when the workload is dominated by a static anonymous/shmem set, the
file set might just be a small window of used-once cache. In such
situations, the VM starts swapping heavily when instead it should be
recycling the no longer used cache.
This is a longer-standing problem, but it's more likely to trigger after
81c0a2bb515f ("mm: page_alloc: fair zone allocator policy") because file
pages can no longer accumulate in a single zone and are dispersed into
smaller fractions among the available zones.
To resolve this, do not force scan anon when file pages are low but
instead rely on the scan/rotation ratios to make the right prediction.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Rafael Aquini <aquini@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Suleiman Souhlal <suleiman@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxx> [3.12+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)
diff -puN mm/vmscan.c~mm-vmscan-do-not-swap-anon-pages-just-because-freefile-is-low mm/vmscan.c
--- a/mm/vmscan.c~mm-vmscan-do-not-swap-anon-pages-just-because-freefile-is-low
+++ a/mm/vmscan.c
@@ -1862,7 +1862,7 @@ static void get_scan_count(struct lruvec
struct zone *zone = lruvec_zone(lruvec);
unsigned long anon_prio, file_prio;
enum scan_balance scan_balance;
- unsigned long anon, file, free;
+ unsigned long anon, file;
bool force_scan = false;
unsigned long ap, fp;
enum lru_list lru;
@@ -1916,20 +1916,6 @@ static void get_scan_count(struct lruvec
get_lru_size(lruvec, LRU_INACTIVE_FILE);
/*
- * If it's foreseeable that reclaiming the file cache won't be
- * enough to get the zone back into a desirable shape, we have
- * to swap. Better start now and leave the - probably heavily
- * thrashing - remaining file pages alone.
- */
- if (global_reclaim(sc)) {
- free = zone_page_state(zone, NR_FREE_PAGES);
- if (unlikely(file + free <= high_wmark_pages(zone))) {
- scan_balance = SCAN_ANON;
- goto out;
- }
- }
-
- /*
* There is enough inactive page cache, do not reclaim
* anything from the anonymous working set right now.
*/
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
origin.patch
pagewalk-update-page-table-walker-core.patch
pagewalk-add-walk_page_vma.patch
smaps-redefine-callback-functions-for-page-table-walker.patch
clear_refs-redefine-callback-functions-for-page-table-walker.patch
pagemap-redefine-callback-functions-for-page-table-walker.patch
numa_maps-redefine-callback-functions-for-page-table-walker.patch
memcg-redefine-callback-functions-for-page-table-walker.patch
arch-powerpc-mm-subpage-protc-use-walk_page_vma-instead-of-walk_page_range.patch
pagewalk-remove-argument-hmask-from-hugetlb_entry.patch
mempolicy-apply-page-table-walker-on-queue_pages_range.patch
debugging-keep-track-of-page-owners.patch
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