• NeilBrown's avatar
    md: remove plug_cnt feature of plugging. · 0021b7bc
    NeilBrown authored
    This seemed like a good idea at the time, but after further thought I
    cannot see it making a difference other than very occasionally and
    testing to try to exercise the case it is most likely to help did not
    show any performance difference by removing it.
    
    So remove the counting of active plugs and allow 'pending writes' to
    be activated at any time, not just when no plugs are active.
    
    This is only relevant when there is a write-intent bitmap, and the
    updating of the bitmap will likely introduce enough delay that
    the single-threading of bitmap updates will be enough to collect large
    numbers of updates together.
    
    Removing this will make it easier to centralise the unplug code, and
    will clear the other for other unplug enhancements which have a
    measurable effect.
    Signed-off-by: default avatarNeilBrown <neilb@suse.de>
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
    0021b7bc
md.h 20.9 KB