• Curt Wohlgemuth's avatar
    ext4: use dedicated slab caches for group_info structures · fb1813f4
    Curt Wohlgemuth authored
    ext4_group_info structures are currently allocated with kmalloc().
    With a typical 4K block size, these are 136 bytes each -- meaning
    they'll each consume a 256-byte slab object.  On a system with many
    ext4 large partitions, that's a lot of wasted kernel slab space.
    (E.g., a single 1TB partition will have about 8000 block groups, using
    about 2MB of slab, of which nearly 1MB is wasted.)
    
    This patch creates an array of slab pointers created as needed --
    depending on the superblock block size -- and uses these slabs to
    allocate the group info objects.
    
    Google-Bug-Id: 2980809
    Signed-off-by: default avatarCurt Wohlgemuth <curtw@google.com>
    Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
    fb1813f4
mballoc.c 128 KB