lkml.org 
[lkml]   [2022]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2 20/28] gup: Convert gup_pte_range() to use a folio
    Date
    We still call try_grab_folio() once per PTE; a future patch could
    optimise to just adjust the reference count for each page within
    the folio.

    Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
    ---
    mm/gup.c | 16 +++++++---------
    1 file changed, 7 insertions(+), 9 deletions(-)

    diff --git a/mm/gup.c b/mm/gup.c
    index c3e514172eaf..27cc097ec05d 100644
    --- a/mm/gup.c
    +++ b/mm/gup.c
    @@ -2235,7 +2235,8 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
    ptem = ptep = pte_offset_map(&pmd, addr);
    do {
    pte_t pte = ptep_get_lockless(ptep);
    - struct page *head, *page;
    + struct page *page;
    + struct folio *folio;

    /*
    * Similar to the PMD case below, NUMA hinting must take slow
    @@ -2262,22 +2263,20 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
    VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
    page = pte_page(pte);

    - head = try_grab_compound_head(page, 1, flags);
    - if (!head)
    + folio = try_grab_folio(page, 1, flags);
    + if (!folio)
    goto pte_unmap;

    if (unlikely(page_is_secretmem(page))) {
    - put_compound_head(head, 1, flags);
    + gup_put_folio(folio, 1, flags);
    goto pte_unmap;
    }

    if (unlikely(pte_val(pte) != pte_val(*ptep))) {
    - put_compound_head(head, 1, flags);
    + gup_put_folio(folio, 1, flags);
    goto pte_unmap;
    }

    - VM_BUG_ON_PAGE(compound_head(page) != head, page);
    -
    /*
    * We need to make the page accessible if and only if we are
    * going to access its content (the FOLL_PIN case). Please
    @@ -2291,10 +2290,9 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
    goto pte_unmap;
    }
    }
    - SetPageReferenced(page);
    + folio_set_referenced(folio);
    pages[*nr] = page;
    (*nr)++;
    -
    } while (ptep++, addr += PAGE_SIZE, addr != end);

    ret = 1;
    --
    2.33.0
    \
     
     \ /
      Last update: 2022-01-10 05:25    [W:4.283 / U:0.732 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site