• Jens Axboe's avatar
    block: add sysfs knob for turning off disk entropy contributions · e2e1a148
    Jens Axboe authored
    There are two reasons for doing this:
    
    - On SSD disks, the completion times aren't as random as they
      are for rotational drives. So it's questionable whether they
      should contribute to the random pool in the first place.
    
    - Calling add_disk_randomness() has a lot of overhead.
    
    This adds /sys/block/<dev>/queue/add_random that will allow you to
    switch off on a per-device basis. The default setting is on, so there
    should be no functional changes from this patch.
    Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
    e2e1a148
blk-sysfs.c 14.5 KB