From fda6d4de064a9d37414df36d45836898fff5e165 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Tue, 20 Aug 2024 17:49:13 +0800 Subject: [PATCH] mm: khugepaged: expand the is_refcount_suitable() to support file folios 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@linux.alibaba.com Link: https://lkml.kernel.org/r/eae4cb3195ebbb654bfb7967cb7261d4e4e7c7fa.1724140601.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang Acked-by: David Hildenbrand Cc: Barry Song <21cnbao@gmail.com> Cc: Hugh Dickins Cc: Matthew Wilcox Cc: Ryan Roberts Cc: Yang Shi Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/khugepaged.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index cdd1d8655a76..76f05215ee87 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -546,12 +546,14 @@ static void release_pte_pages(pte_t *pte, 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(struct mm_struct *mm, unsigned long addr, break; } - if (folio_ref_count(folio) != - 1 + folio_mapcount(folio) + folio_test_private(folio)) { + if (!is_refcount_suitable(folio)) { result = SCAN_PAGE_COUNT; break; }