• Shaohua Li's avatar
    writeback: move inodes from one super_block together · 5c03449d
    Shaohua Li authored
    __mark_inode_dirty adds inode to wb dirty list in random order. If a disk has
    several partitions, writeback might keep spindle moving between partitions.
    To reduce the move, better write big chunk of one partition and then move to
    another. Inodes from one fs usually are in one partion, so idealy move indoes
    from one fs together should reduce spindle move. This patch tries to address
    this. Before per-bdi writeback is added, the behavior is write indoes
    from one fs first and then another, so the patch restores previous behavior.
    The loop in the patch is a bit ugly, should we add a dirty list for each
    superblock in bdi_writeback?
    
    Test in a two partition disk with attached fio script shows about 3% ~ 6%
    improvement.
    Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
    Reviewed-by: default avatarWu Fengguang <fengguang.wu@intel.com>
    Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
    5c03449d
fs-writeback.c 32.3 KB