From: Baolin Wang baolin.wang@linux.alibaba.com
mainline inclusion from mainline-v6.12-rc1 commit fda6d4de064a9d37414df36d45836898fff5e165 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAXCD2
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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.172414060... Signed-off-by: Baolin Wang baolin.wang@linux.alibaba.com Acked-by: David Hildenbrand david@redhat.com Cc: Barry Song 21cnbao@gmail.com Cc: Hugh Dickins hughd@google.com Cc: Matthew Wilcox willy@infradead.org Cc: Ryan Roberts ryan.roberts@arm.com Cc: Yang Shi shy828301@gmail.com Cc: Zi Yan ziy@nvidia.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Nanyong Sun sunnanyong@huawei.com --- mm/khugepaged.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index d585ee8357da..007684e8b888 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -555,12 +555,14 @@ 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; }
@@ -2300,8 +2302,7 @@ 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; }