• Josef Bacik's avatar
    Btrfs: make fsync latency less sucky · 5039eddc
    Josef Bacik authored
    
    
    Looking into some performance related issues with large amounts of metadata
    revealed that we can have some pretty huge swings in fsync() performance.  If we
    have a lot of delayed refs backed up (as you will tend to do with lots of
    metadata) fsync() will wander off and try to run some of those delayed refs
    which can result in reading from disk and such.  Since the actual act of fsync()
    doesn't create any delayed refs there is no need to make it throttle on delayed
    ref stuff, that will be handled by other people.  With this patch we get much
    smoother fsync performance with large amounts of metadata.  Thanks,
    Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
    Signed-off-by: default avatarChris Mason <clm@fb.com>
    5039eddc