The patch titled Subject: huge_memory: convert do_huge_pmd_wp_page() to use a folio has been added to the -mm mm-unstable branch. Its filename is huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: huge_memory: convert do_huge_pmd_wp_page() to use a folio Date: Fri, 2 Sep 2022 20:46:38 +0100 Removes many calls to compound_head(). Does not remove the assumption that a folio may not be larger than a PMD. Link: https://lkml.kernel.org/r/20220902194653.1739778-43-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/huge_memory.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) --- a/mm/huge_memory.c~huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio +++ a/mm/huge_memory.c @@ -1305,6 +1305,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm { const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; struct vm_area_struct *vma = vmf->vma; + struct folio *folio; struct page *page; unsigned long haddr = vmf->address & HPAGE_PMD_MASK; pmd_t orig_pmd = vmf->orig_pmd; @@ -1326,46 +1327,48 @@ vm_fault_t do_huge_pmd_wp_page(struct vm } page = pmd_page(orig_pmd); + folio = page_folio(page); VM_BUG_ON_PAGE(!PageHead(page), page); /* Early check when only holding the PT lock. */ if (PageAnonExclusive(page)) goto reuse; - if (!trylock_page(page)) { - get_page(page); + if (!folio_trylock(folio)) { + folio_get(folio); spin_unlock(vmf->ptl); - lock_page(page); + folio_lock(folio); spin_lock(vmf->ptl); if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) { spin_unlock(vmf->ptl); - unlock_page(page); - put_page(page); + folio_unlock(folio); + folio_put(folio); return 0; } - put_page(page); + folio_put(folio); } /* Recheck after temporarily dropping the PT lock. */ if (PageAnonExclusive(page)) { - unlock_page(page); + folio_unlock(folio); goto reuse; } /* - * See do_wp_page(): we can only reuse the page exclusively if there are - * no additional references. Note that we always drain the LRU - * pagevecs immediately after adding a THP. + * See do_wp_page(): we can only reuse the folio exclusively if + * there are no additional references. Note that we always drain + * the LRU pagevecs immediately after adding a THP. */ - if (page_count(page) > 1 + PageSwapCache(page) * thp_nr_pages(page)) + if (folio_ref_count(folio) > + 1 + folio_test_swapcache(folio) * folio_nr_pages(folio)) goto unlock_fallback; - if (PageSwapCache(page)) - try_to_free_swap(page); - if (page_count(page) == 1) { + if (folio_test_swapcache(folio)) + folio_free_swap(folio); + if (folio_ref_count(folio) == 1) { pmd_t entry; page_move_anon_rmap(page, vma); - unlock_page(page); + folio_unlock(folio); reuse: if (unlikely(unshare)) { spin_unlock(vmf->ptl); @@ -1380,7 +1383,7 @@ reuse: } unlock_fallback: - unlock_page(page); + folio_unlock(folio); spin_unlock(vmf->ptl); fallback: __split_huge_pmd(vma, vmf->pmd, vmf->address, false, NULL); _ Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are tools-fix-compilation-after-gfp_typesh-split.patch mm-fix-vm_bug_on-in-__delete_from_swap_cache.patch vmscan-check-folio_test_private-not-folio_get_private.patch support-highmem-pages-in-vmap_pages_range_noflush.patch mm-add-vma-iterator.patch mmap-use-the-vma-iterator-in-count_vma_pages_range.patch proc-remove-vma-rbtree-use-from-nommu.patch arm64-remove-mmap-linked-list-from-vdso.patch parisc-remove-mmap-linked-list-from-cache-handling.patch powerpc-remove-mmap-linked-list-walks.patch s390-remove-vma-linked-list-walks.patch x86-remove-vma-linked-list-walks.patch xtensa-remove-vma-linked-list-walks.patch cxl-remove-vma-linked-list-walk.patch optee-remove-vma-linked-list-walk.patch um-remove-vma-linked-list-walk.patch coredump-remove-vma-linked-list-walk.patch exec-use-vma-iterator-instead-of-linked-list.patch fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end.patch acct-use-vma-iterator-instead-of-linked-list.patch perf-use-vma-iterator.patch sched-use-maple-tree-iterator-to-walk-vmas.patch fork-use-vma-iterator.patch mm-khugepaged-stop-using-vma-linked-list.patch mm-ksm-use-vma-iterators-instead-of-vma-linked-list.patch mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch mm-pagewalk-use-vma_find-instead-of-vma-linked-list.patch i915-use-the-vma-iterator.patch nommu-remove-uses-of-vma-linked-list.patch mm-vmscan-fix-a-lot-of-comments.patch mm-add-the-first-tail-page-to-struct-folio.patch mm-reimplement-folio_order-and-folio_nr_pages.patch mm-add-split_folio.patch mm-add-folio_add_lru_vma.patch shmem-convert-shmem_writepage-to-use-a-folio-throughout.patch shmem-convert-shmem_delete_from_page_cache-to-take-a-folio.patch shmem-convert-shmem_replace_page-to-use-folios-throughout.patch mm-swapfile-remove-page_swapcount.patch mm-swapfile-convert-try_to_free_swap-to-folio_free_swap.patch mm-swap-convert-__read_swap_cache_async-to-use-a-folio.patch mm-swap-convert-add_to_swap_cache-to-take-a-folio.patch mm-swap-convert-put_swap_page-to-put_swap_folio.patch mm-convert-do_swap_page-to-use-a-folio.patch mm-convert-do_swap_pages-swapcache-variable-to-a-folio.patch memcg-convert-mem_cgroup_swapin_charge_page-to-mem_cgroup_swapin_charge_folio.patch shmem-convert-shmem_mfill_atomic_pte-to-use-a-folio.patch shmem-convert-shmem_replace_page-to-shmem_replace_folio.patch swap-add-swap_cache_get_folio.patch shmem-eliminate-struct-page-from-shmem_swapin_folio.patch shmem-convert-shmem_getpage_gfp-to-shmem_get_folio_gfp.patch shmem-convert-shmem_fault-to-use-shmem_get_folio_gfp.patch shmem-convert-shmem_read_mapping_page_gfp-to-use-shmem_get_folio_gfp.patch shmem-add-shmem_get_folio.patch shmem-convert-shmem_get_partial_folio-to-use-shmem_get_folio.patch shmem-convert-shmem_write_begin-to-use-shmem_get_folio.patch shmem-convert-shmem_file_read_iter-to-use-shmem_get_folio.patch shmem-convert-shmem_fallocate-to-use-a-folio.patch shmem-convert-shmem_symlink-to-use-a-folio.patch shmem-convert-shmem_get_link-to-use-a-folio.patch khugepaged-call-shmem_get_folio.patch userfaultfd-convert-mcontinue_atomic_pte-to-use-a-folio.patch shmem-remove-shmem_getpage.patch swapfile-convert-try_to_unuse-to-use-a-folio.patch swapfile-convert-__try_to_reclaim_swap-to-use-a-folio.patch swapfile-convert-unuse_pte_range-to-use-a-folio.patch mm-convert-do_swap_page-to-use-swap_cache_get_folio.patch mm-remove-lookup_swap_cache.patch swap_state-convert-free_swap_cache-to-use-a-folio.patch swap-convert-swap_writepage-to-use-a-folio.patch mm-convert-do_wp_page-to-use-a-folio.patch huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch madvise-convert-madvise_free_pte_range-to-use-a-folio.patch uprobes-use-folios-more-widely-in-__replace_page.patch ksm-use-a-folio-in-replace_page.patch mm-convert-do_swap_page-to-use-folio_free_swap.patch memcg-convert-mem_cgroup_swap_full-to-take-a-folio.patch mm-remove-try_to_free_swap.patch rmap-convert-page_move_anon_rmap-to-use-a-folio.patch migrate-convert-__unmap_and_move-to-use-folios.patch migrate-convert-unmap_and_move_huge_page-to-use-folios.patch huge_memory-convert-split_huge_page_to_list-to-use-a-folio.patch huge_memory-convert-unmap_page-to-unmap_folio.patch mm-convert-page_get_anon_vma-to-folio_get_anon_vma.patch rmap-remove-page_unlock_anon_vma_read.patch uprobes-use-new_folio-in-__replace_page.patch mm-convert-lock_page_or_retry-to-folio_lock_or_retry.patch