• Jens Axboe's avatar
    null_blk: add blocking mode · db5bcf87
    Jens Axboe authored
    This adds a new module parameter to null_blk, blocking. If set, null_blk
    will set the BLK_MQ_F_BLOCKING flag, indicating that it sometimes/always
    needs to block in its ->queue_rq() function.  The intent is to help find
    regressions in blocking drivers, since not many of them exist.
    
    If null_blk is loaded with submit_queues > 1 and blocking=1, this
    shows the regression recently fixed by bf4907c0.
    Reviewed-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
    Signed-off-by: default avatarJens Axboe <axboe@fb.com>
    db5bcf87
null_blk.c 19.1 KB