diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h index 384e29f6bef0..bcdc57eea270 100644 --- a/include/trace/events/huge_memory.h +++ b/include/trace/events/huge_memory.h @@ -25,6 +25,7 @@ EM( SCAN_PAGE_LRU, "page_not_in_lru") \ EM( SCAN_PAGE_LOCK, "page_locked") \ EM( SCAN_PAGE_ANON, "page_not_anon") \ + EM( SCAN_PAGE_LAZYFREE, "page_lazyfree") \ EM( SCAN_PAGE_COMPOUND, "page_compound") \ EM( SCAN_ANY_PROCESS, "no_process_for_page") \ EM( SCAN_VMA_NULL, "vma_null") \ diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 8ee3c44bc851..13b0fe50dfc5 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -46,6 +46,7 @@ enum scan_result { SCAN_PAGE_LRU, SCAN_PAGE_LOCK, SCAN_PAGE_ANON, + SCAN_PAGE_LAZYFREE, SCAN_PAGE_COMPOUND, SCAN_ANY_PROCESS, SCAN_VMA_NULL, @@ -577,6 +578,16 @@ static enum scan_result __collapse_huge_page_isolate(struct vm_area_struct *vma, folio = page_folio(page); VM_BUG_ON_FOLIO(!folio_test_anon(folio), folio); + /* + * If the vma has the VM_DROPPABLE flag, the collapse will + * preserve the lazyfree property without needing to skip. + */ + if (cc->is_khugepaged && !(vma->vm_flags & VM_DROPPABLE) && + folio_test_lazyfree(folio) && !pte_dirty(pteval)) { + result = SCAN_PAGE_LAZYFREE; + goto out; + } + /* See hpage_collapse_scan_pmd(). */ if (folio_maybe_mapped_shared(folio)) { ++shared; @@ -1325,6 +1336,16 @@ static enum scan_result hpage_collapse_scan_pmd(struct mm_struct *mm, } folio = page_folio(page); + /* + * If the vma has the VM_DROPPABLE flag, the collapse will + * preserve the lazyfree property without needing to skip. + */ + if (cc->is_khugepaged && !(vma->vm_flags & VM_DROPPABLE) && + folio_test_lazyfree(folio) && !pte_dirty(pteval)) { + result = SCAN_PAGE_LAZYFREE; + goto out_unmap; + } + if (!folio_test_anon(folio)) { result = SCAN_PAGE_ANON; goto out_unmap;