• Andrew Morton's avatar
    [PATCH] pdflush exclusion · 17a74e88
    Andrew Morton authored
    Use the pdflush exclusion infrastructure to ensure that only one
    pdlfush thread is ever performing writeback against a particular
    request_queue.
    
    This works rather well.  It requires a lot of activity against a lot of
    disks to cause more pdflush threads to start up.  Possibly the
    thread-creation logic is a little weak: it starts more threads when a
    pdflush thread goes back to sleep.  It may be better to start new
    threads within pdlfush_operation().
    
    All non-request_queue-backed address_spaces share the global
    default_backing_dev_info structure.  So at present only a single
    pdflush instance will be available for background writeback of *all*
    NFS filesystems (for example).
    
    If there is benefit in concurrent background writeback for multiple NFS
    mounts then NFS would need to create per-mount backing_dev_info
    structures and install those into new inode's address_spaces in some
    manner.
    17a74e88
page-writeback.c 14.7 KB