The patch titled
Subject: mm: consider all swapped back pages in used-once logic
has been removed from the -mm tree. Its filename was
mm-consider-all-swapped-back-pages-in-used-once-logic.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
From: Michal Hocko <[email protected]>
Subject: mm: consider all swapped back pages in used-once logic
Commit 64574746 ("vmscan: detect mapped file pages used only once") made
mapped pages have another round in inactive list because they might be
just short lived and so we could consider them again next time. This
heuristic helps to reduce pressure on the active list with a streaming IO
worklods.
This patch fixes a regression introduced by this commit for heavy shmem
based workloads because unlike Anon pages, which are excluded from this
heuristic because they are usually long lived, shmem pages are handled as
a regular page cache.
This doesn't work quite well, unfortunately, if the workload is mostly
backed by shmem (in memory database sitting on 80% of memory) with a
streaming IO in the background (backup - up to 20% of memory). Anon
inactive list is full of (dirty) shmem pages when watermarks are hit.
Shmem pages are kept in the inactive list (they are referenced) in the
first round and it is hard to reclaim anything else so we reach lower
scanning priorities very quickly which leads to an excessive swap out.
Let's fix this by excluding all swap backed pages (they tend to be long
lived wrt. the regular page cache anyway) from used-once heuristic and
rather activate them if they are referenced.
The customer's workload is shmem backed database (80% of RAM) and they are
measuring transactions/s with an IO in the background (20%). Transactions
touch more or less random rows in the table. The transaction rate fell by
a factor of 3 (in the worst case) because of commit 64574746. This patch
restores the previous numbers.
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Cc: <[email protected]> [2.6.34+]
Signed-off-by: Andrew Morton <[email protected]>
---
mm/vmscan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/vmscan.c~mm-consider-all-swapped-back-pages-in-used-once-logic
mm/vmscan.c
--- a/mm/vmscan.c~mm-consider-all-swapped-back-pages-in-used-once-logic
+++ a/mm/vmscan.c
@@ -657,7 +657,7 @@ static enum page_references page_check_r
return PAGEREF_RECLAIM;
if (referenced_ptes) {
- if (PageAnon(page))
+ if (PageSwapBacked(page))
return PAGEREF_ACTIVATE;
/*
* All mapped pages start out with page table
_
Patches currently in -mm which might be from [email protected] are
origin.patch
hugetlb-rename-max_hstate-to-hugetlb_max_hstate.patch
hugetlbfs-dont-use-err_ptr-with-vm_fault-values.patch
hugetlbfs-add-an-inline-helper-for-finding-hstate-index.patch
hugetlbfs-add-an-inline-helper-for-finding-hstate-index-fix.patch
hugetlb-use-mmu_gather-instead-of-a-temporary-linked-list-for-accumulating-pages.patch
hugetlb-use-mmu_gather-instead-of-a-temporary-linked-list-for-accumulating-pages-fix.patch
hugetlb-use-mmu_gather-instead-of-a-temporary-linked-list-for-accumulating-pages-fix-fix.patch
hugetlb-avoid-taking-i_mmap_mutex-in-unmap_single_vma-for-hugetlb.patch
hugetlb-simplify-migrate_huge_page.patch
hugetlb-simplify-migrate_huge_page-fix.patch
memcg-add-hugetlb-extension.patch
memcg-add-hugetlb-extension-fix.patch
memcg-add-hugetlb-extension-fix-fix.patch
hugetlb-add-charge-uncharge-calls-for-hugetlb-alloc-free.patch
memcg-track-resource-index-in-cftype-private.patch
hugetlbfs-add-memcg-control-files-for-hugetlbfs.patch
hugetlbfs-add-memcg-control-files-for-hugetlbfs-use-scnprintf-instead-of-sprintf.patch
hugetlbfs-add-memcg-control-files-for-hugetlbfs-use-scnprintf-instead-of-sprintf-fix.patch
hugetlbfs-add-memcg-control-files-for-hugetlbfs-add-failcnt-support-for-hugetlb-extension.patch
hugetlbfs-add-a-list-for-tracking-in-use-hugetlb-pages.patch
memcg-move-hugetlb-resource-count-to-parent-cgroup-on-memcg-removal.patch
memcg-move-hugetlb-resource-count-to-parent-cgroup-on-memcg-removal-fix.patch
memcg-move-hugetlb-resource-count-to-parent-cgroup-on-memcg-removal-fix-fix.patch
hugetlb-migrate-memcg-info-from-oldpage-to-new-page-during-migration.patch
memcg-add-memory-controller-documentation-for-hugetlb-management.patch
memcg-fix-error-code-in-hugetlb_force_memcg_empty.patch
memcg-use-res_counter_uncharge_until-in-mem_cgroup_move_hugetlb_parent.patch
memcg-move-charges-to-root-cgroup-if-use_hierarchy=0-in-mem_cgroup_move_hugetlb_parent.patch
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