The patch titled
Subject: mm: page_alloc: allowing mTHP compaction to capture the freed page directly
has been added to the -mm mm-unstable branch. Its filename is
mm-page_alloc-allowing-mthp-compaction-to-capture-the-freed-page-directly.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-allowing-mthp-compaction-to-capture-the-freed-page-directly.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Subject: mm: page_alloc: allowing mTHP compaction to capture the freed page directly
Date: Fri, 12 Apr 2024 11:27:04 +0800
Currently, compaction_capture() does not allow lower-order allocations to
directly capture the movable free pages, even though lower-order
allocations might also be requesting movable pages, that can lead to more
compaction scanning. And, with the enablement of mTHP, such situations
will become more common.
Thus allowing lower-order (mTHP) allocations of movable page types
directly capture the movable free pages can avoid unnecessary compaction
scanning, meanwhile that won't pollute the movable pageblock. With
testing 1M mTHP compaction, it can be seen that compaction scanning is
significantly reduced.
mm-unstable patched
Ops Compaction pages isolated 116598741.00 120946702.00
Ops Compaction migrate scanned 1764870054.00 1488621550.00
Ops Compaction free scanned 7707879039.00 4986299318.00
Ops Compact scan efficiency 22.90 29.85
Ops Compaction cost 73797.69 72933.48
Link: https://lkml.kernel.org/r/8118a5d66a034736a48433beddaca60ed78577c4.1712892329.git.baolin.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-allowing-mthp-compaction-to-capture-the-freed-page-directly
+++ a/mm/page_alloc.c
@@ -595,12 +595,14 @@ compaction_capture(struct capture_contro
return false;
/*
- * Do not let lower order allocations pollute a movable pageblock.
+ * Do not let lower order allocations pollute a movable pageblock
+ * unless compaction is also requesting movable pages.
* This might let an unmovable request use a reclaimable pageblock
* and vice-versa but no more than normal fallback logic which can
* have trouble finding a high-order free page.
*/
- if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
+ if (order < pageblock_order && migratetype == MIGRATE_MOVABLE &&
+ capc->cc->migratetype != MIGRATE_MOVABLE)
return false;
capc->page = page;
_
Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are
mm-page_alloc-fix-freelist-movement-during-block-conversion-fix.patch
mm-page_alloc-consolidate-free-page-accounting-fix-3.patch
mm-record-the-migration-reason-for-struct-migration_target_control.patch
mm-hugetlb-make-the-hugetlb-migration-strategy-consistent.patch
docs-hugetlbpagerst-add-hugetlb-migration-description.patch
mm-factor-out-the-numa-mapping-rebuilding-into-a-new-helper.patch
mm-support-multi-size-thp-numa-balancing.patch
mm-support-multi-size-thp-numa-balancing-v3.patch
mm-huge_memory-add-the-missing-folio_test_pmd_mappable-for-thp-split-statistics.patch
mm-page_alloc-use-the-correct-thp-order-for-thp-pcp.patch
mm-set-pageblock_order-to-hpage_pmd_order-in-case-with-config_hugetlb_page-but-thp-enabled.patch
mm-page_alloc-allowing-mthp-compaction-to-capture-the-freed-page-directly.patch
