The patch titled Subject: mm/gup: refactor record_subpages() to find 1st small page has been added to the -mm mm-unstable branch. Its filename is mm-gup-refactor-record_subpages-to-find-1st-small-page.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-gup-refactor-record_subpages-to-find-1st-small-page.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: Peter Xu <peterx@xxxxxxxxxx> Subject: mm/gup: refactor record_subpages() to find 1st small page Date: Wed, 27 Mar 2024 11:23:26 -0400 All the fast-gup functions take a tail page to operate, always need to do page mask calculations before feeding that into record_subpages(). Merge that logic into record_subpages(), so that it will do the nth_page() calculation. Link: https://lkml.kernel.org/r/20240327152332.950956-8-peterx@xxxxxxxxxx Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Andrew Jones <andrew.jones@xxxxxxxxx> Cc: Aneesh Kumar K.V (IBM) <aneesh.kumar@xxxxxxxxxx> Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: James Houghton <jthoughton@xxxxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx> Cc: Muchun Song <muchun.song@xxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/gup.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) --- a/mm/gup.c~mm-gup-refactor-record_subpages-to-find-1st-small-page +++ a/mm/gup.c @@ -2787,13 +2787,16 @@ static int __gup_device_huge_pud(pud_t p } #endif -static int record_subpages(struct page *page, unsigned long addr, - unsigned long end, struct page **pages) +static int record_subpages(struct page *page, unsigned long sz, + unsigned long addr, unsigned long end, + struct page **pages) { + struct page *start_page; int nr; + start_page = nth_page(page, (addr & (sz - 1)) >> PAGE_SHIFT); for (nr = 0; addr != end; nr++, addr += PAGE_SIZE) - pages[nr] = nth_page(page, nr); + pages[nr] = nth_page(start_page, nr); return nr; } @@ -2828,8 +2831,8 @@ static int gup_hugepte(pte_t *ptep, unsi /* hugepages are never "special" */ VM_BUG_ON(!pfn_valid(pte_pfn(pte))); - page = nth_page(pte_page(pte), (addr & (sz - 1)) >> PAGE_SHIFT); - refs = record_subpages(page, addr, end, pages + *nr); + page = pte_page(pte); + refs = record_subpages(page, sz, addr, end, pages + *nr); folio = try_grab_folio(page, refs, flags); if (!folio) @@ -2902,8 +2905,8 @@ static int gup_huge_pmd(pmd_t orig, pmd_ pages, nr); } - page = nth_page(pmd_page(orig), (addr & ~PMD_MASK) >> PAGE_SHIFT); - refs = record_subpages(page, addr, end, pages + *nr); + page = pmd_page(orig); + refs = record_subpages(page, PMD_SIZE, addr, end, pages + *nr); folio = try_grab_folio(page, refs, flags); if (!folio) @@ -2946,8 +2949,8 @@ static int gup_huge_pud(pud_t orig, pud_ pages, nr); } - page = nth_page(pud_page(orig), (addr & ~PUD_MASK) >> PAGE_SHIFT); - refs = record_subpages(page, addr, end, pages + *nr); + page = pud_page(orig); + refs = record_subpages(page, PUD_SIZE, addr, end, pages + *nr); folio = try_grab_folio(page, refs, flags); if (!folio) @@ -2986,8 +2989,8 @@ static int gup_huge_pgd(pgd_t orig, pgd_ BUILD_BUG_ON(pgd_devmap(orig)); - page = nth_page(pgd_page(orig), (addr & ~PGDIR_MASK) >> PAGE_SHIFT); - refs = record_subpages(page, addr, end, pages + *nr); + page = pgd_page(orig); + refs = record_subpages(page, PGDIR_SIZE, addr, end, pages + *nr); folio = try_grab_folio(page, refs, flags); if (!folio) _ Patches currently in -mm which might be from peterx@xxxxxxxxxx are mm-hmm-process-pud-swap-entry-without-pud_huge.patch mm-gup-cache-p4d-in-follow_p4d_mask.patch mm-gup-check-p4d-presence-before-going-on.patch mm-x86-change-pxd_huge-behavior-to-exclude-swap-entries.patch mm-sparc-change-pxd_huge-behavior-to-exclude-swap-entries.patch mm-arm-use-macros-to-define-pmd-pud-helpers.patch mm-arm-redefine-pmd_huge-with-pmd_leaf.patch mm-arm64-merge-pxd_huge-and-pxd_leaf-definitions.patch mm-powerpc-redefine-pxd_huge-with-pxd_leaf.patch mm-gup-merge-pxd-huge-mapping-checks.patch mm-treewide-replace-pxd_huge-with-pxd_leaf.patch mm-treewide-remove-pxd_huge.patch mm-arm-remove-pmd_thp_or_huge.patch mm-document-pxd_leaf-api.patch selftests-mm-run_vmtestssh-fix-hugetlb-mem-size-calculation.patch mm-kconfig-config_pgtable_has_huge_leaves.patch mm-hugetlb-declare-hugetlbfs_pagecache_present-non-static.patch mm-make-hpage_pxd_-macros-even-if-thp.patch mm-introduce-vma_pgtable_walk_beginend.patch mm-arch-provide-pud_pfn-fallback.patch mm-gup-drop-folio_fast_pin_allowed-in-hugepd-processing.patch mm-gup-refactor-record_subpages-to-find-1st-small-page.patch mm-gup-handle-hugetlb-for-no_page_table.patch mm-gup-cache-pudp-in-follow_pud_mask.patch mm-gup-handle-huge-pud-for-follow_pud_mask.patch mm-gup-handle-huge-pmd-for-follow_pmd_mask.patch mm-gup-handle-hugepd-for-follow_page.patch mm-gup-handle-hugetlb-in-the-generic-follow_page_mask-code.patch