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
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------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm/gup: refactor record_subpages() to find 1st small page
Date: Thu, 21 Mar 2024 18:07:56 -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/20240321220802.679544-7-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" <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
@@ -2778,13 +2778,16 @@ 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;
}
@@ -2819,8 +2822,8 @@ 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)
@@ -2893,8 +2896,8 @@ 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)
@@ -2937,8 +2940,8 @@ 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)
@@ -2977,8 +2980,8 @@ 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-memory-fix-missing-pte-marker-for-page-on-pte-zaps.patch
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
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-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
