The patch titled
Subject: mm: khugepaged: expand the is_refcount_suitable() to support file folios
has been added to the -mm mm-unstable branch. Its filename is
mm-khugepaged-expand-the-is_refcount_suitable-to-support-file-folios.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-expand-the-is_refcount_suitable-to-support-file-folios.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: khugepaged: expand the is_refcount_suitable() to support file folios
Date: Tue, 20 Aug 2024 17:49:13 +0800
Patch series "support shmem mTHP collapse", v2.
Shmem already supports mTHP allocation[1], and this patchset adds support
for shmem mTHP collapse, as well as adding relevant test cases.
This patch (of 5):
Expand the is_refcount_suitable() to support reference checks for file
folios, as preparation for supporting shmem mTHP collapse.
Link: https://lkml.kernel.org/r/cover.1724140601.git.baolin.wang@xxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/eae4cb3195ebbb654bfb7967cb7261d4e4e7c7fa.1724140601.git.baolin.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Barry Song <21cnbao@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/khugepaged.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
--- a/mm/khugepaged.c~mm-khugepaged-expand-the-is_refcount_suitable-to-support-file-folios
+++ a/mm/khugepaged.c
@@ -546,12 +546,14 @@ static void release_pte_pages(pte_t *pte
static bool is_refcount_suitable(struct folio *folio)
{
- int expected_refcount;
+ int expected_refcount = folio_mapcount(folio);
- expected_refcount = folio_mapcount(folio);
- if (folio_test_swapcache(folio))
+ if (!folio_test_anon(folio) || folio_test_swapcache(folio))
expected_refcount += folio_nr_pages(folio);
+ if (folio_test_private(folio))
+ expected_refcount++;
+
return folio_ref_count(folio) == expected_refcount;
}
@@ -2285,8 +2287,7 @@ static int hpage_collapse_scan_file(stru
break;
}
- if (folio_ref_count(folio) !=
- 1 + folio_mapcount(folio) + folio_test_private(folio)) {
+ if (!is_refcount_suitable(folio)) {
result = SCAN_PAGE_COUNT;
break;
}
_
Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are
mm-shmem-simplify-the-suitable-huge-orders-validation-for-tmpfs.patch
mm-shmem-rename-shmem_is_huge-to-shmem_huge_global_enabled.patch
mm-shmem-move-shmem_huge_global_enabled-into-shmem_allowable_huge_orders.patch
mm-swap-extend-swap_shmem_alloc-to-support-batch-swap_map_shmem-flag-setting.patch
mm-shmem-extend-shmem_partial_swap_usage-to-support-large-folio-swap.patch
mm-filemap-use-xa_get_order-to-get-the-swap-entry-order.patch
mm-shmem-use-swap_free_nr-to-free-shmem-swap-entries.patch
mm-shmem-support-large-folio-allocation-for-shmem_replace_folio.patch
mm-shmem-drop-folio-reference-count-using-nr_pages-in-shmem_delete_from_page_cache.patch
mm-shmem-split-large-entry-if-the-swapin-folio-is-not-large.patch
mm-shmem-support-large-folio-swap-out.patch
mm-khugepaged-expand-the-is_refcount_suitable-to-support-file-folios.patch
mm-khugepaged-use-the-number-of-pages-in-the-folio-to-check-the-reference-count.patch
mm-khugepaged-support-shmem-mthp-copy.patch
mm-khugepaged-support-shmem-mthp-collapse.patch
selftests-mm-support-shmem-mthp-collapse-testing.patch
