• Vlastimil Babka's avatar
    mm, page_owner: copy page owner info during migration · d435edca
    Vlastimil Babka authored
    The page_owner mechanism stores gfp_flags of an allocation and stack
    trace that lead to it.  During page migration, the original information
    is practically replaced by the allocation of free page as the migration
    target.  Arguably this is less useful and might lead to all the
    page_owner info for migratable pages gradually converge towards
    compaction or numa balancing migrations.  It has also lead to
    inaccuracies such as one fixed by commit e2cfc911 ("mm/page_owner:
    set correct gfp_mask on page_owner").
    
    This patch thus introduces copying the page_owner info during migration.
    However, since the fact that the page has been migrated from its
    original place might be useful for debugging, the next patch will
    introduce a way to track that information as well.
    Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
    Acked-by: default avatarMichal Hocko <mhocko@suse.com>
    Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
    Cc: Minchan Kim <minchan@kernel.org>
    Cc: Sasha Levin <sasha.levin@oracle.com>
    Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
    d435edca
migrate.c 47.8 KB