From: Peter Xu <peterx@xxxxxxxxxx> Subject: mm: rework swap handling of zap_pte_range Clean the code up by merging the device private/exclusive swap entry handling with the rest, then we merge the pte clear operation too. struct* page is defined in multiple places in the function, move it upward. free_swap_and_cache() is only useful for !non_swap_entry() case, put it into the condition. No functional change intended. Link: https://lkml.kernel.org/r/20220216094810.60572-5-peterx@xxxxxxxxxx Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: "Kirill A . Shutemov" <kirill@xxxxxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Alistair Popple <apopple@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) --- a/mm/memory.c~mm-rework-swap-handling-of-zap_pte_range +++ a/mm/memory.c @@ -1361,6 +1361,8 @@ again: arch_enter_lazy_mmu_mode(); do { pte_t ptent = *pte; + struct page *page; + if (pte_none(ptent)) continue; @@ -1368,8 +1370,6 @@ again: break; if (pte_present(ptent)) { - struct page *page; - page = vm_normal_page(vma, addr, ptent); if (unlikely(!should_zap_page(details, page))) continue; @@ -1403,28 +1403,21 @@ again: entry = pte_to_swp_entry(ptent); if (is_device_private_entry(entry) || is_device_exclusive_entry(entry)) { - struct page *page = pfn_swap_entry_to_page(entry); - + page = pfn_swap_entry_to_page(entry); if (unlikely(!should_zap_page(details, page))) continue; - pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); rss[mm_counter(page)]--; - if (is_device_private_entry(entry)) page_remove_rmap(page, false); - put_page(page); - continue; - } - - if (!non_swap_entry(entry)) { + } else if (!non_swap_entry(entry)) { /* Genuine swap entry, hence a private anon page */ if (!should_zap_cows(details)) continue; rss[MM_SWAPENTS]--; + if (unlikely(!free_swap_and_cache(entry))) + print_bad_pte(vma, addr, ptent, NULL); } else if (is_migration_entry(entry)) { - struct page *page; - page = pfn_swap_entry_to_page(entry); if (!should_zap_page(details, page)) continue; @@ -1436,8 +1429,6 @@ again: /* We should have covered all the swap entry types */ WARN_ON_ONCE(1); } - if (unlikely(!free_swap_and_cache(entry))) - print_bad_pte(vma, addr, ptent, NULL); pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); } while (pte++, addr += PAGE_SIZE, addr != end); _
