• Michel Lespinasse's avatar
    mm: accelerate mm_populate() treatment of THP pages · 240aadee
    Michel Lespinasse authored
    This change adds a follow_page_mask function which is equivalent to
    follow_page, but with an extra page_mask argument.
    
    follow_page_mask sets *page_mask to HPAGE_PMD_NR - 1 when it encounters
    a THP page, and to 0 in other cases.
    
    __get_user_pages() makes use of this in order to accelerate populating
    THP ranges - that is, when both the pages and vmas arrays are NULL, we
    don't need to iterate HPAGE_PMD_NR times to cover a single THP page (and
    we also avoid taking mm->page_table_lock that many times).
    Signed-off-by: default avatarMichel Lespinasse <walken@google.com>
    Cc: Andrea Arcangeli <aarcange@redhat.com>
    Cc: Rik van Riel <riel@redhat.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Cc: Hugh Dickins <hughd@google.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    240aadee
nommu.c 51.5 KB