• Steven Whitehouse's avatar
    GFS2: Kill two daemons with one patch · 97cc1025
    Steven Whitehouse authored
    This patch removes the two daemons, gfs2_scand and gfs2_glockd
    and replaces them with a shrinker which is called from the VM.
    
    The net result is that GFS2 responds better when there is memory
    pressure, since it shrinks the glock cache at the same rate
    as the VFS shrinks the dcache and icache. There are no longer
    any time based criteria for shrinking glocks, they are kept
    until such time as the VM asks for more memory and then we
    demote just as many glocks as required.
    
    There are potential future changes to this code, including the
    possibility of sorting the glocks which are to be written back
    into inode number order, to get a better I/O ordering. It would
    be very useful to have an elevator based workqueue implementation
    for this, as that would automatically deal with the read I/O cases
    at the same time.
    
    This patch is my answer to Andrew Morton's remark, made during
    the initial review of GFS2, asking why GFS2 needs so many kernel
    threads, the answer being that it doesn't :-) This patch is a
    net loss of about 200 lines of code.
    Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    97cc1025
glock.h 4.01 KB