Similar to the anonymous folios collapse, we should also check the 'max_ptes_none' when trying to collapse shmem/file folios, which is also intended as preparation for shmem mTHP collapse in the following patches.
Signed-off-by: Baolin Wang <[email protected]> --- mm/khugepaged.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index b12187709f6d..631459172e19 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -2234,6 +2234,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr, struct file *file, pgoff_t start, struct collapse_control *cc) { + const unsigned int max_ptes_none = collapse_max_ptes_none(cc, NULL, HPAGE_PMD_ORDER); struct address_space *mapping = file->f_mapping; struct page *dst; struct folio *folio, *tmp, *new_folio; @@ -2299,7 +2300,13 @@ static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr, goto xa_locked; } } - nr_none++; + + if (++nr_none > max_ptes_none) { + result = SCAN_EXCEED_NONE_PTE; + count_vm_event(THP_SCAN_EXCEED_NONE_PTE); + goto xa_locked; + } + index++; continue; } -- 2.47.3
