• Jens Axboe's avatar
    blk-mq: make the polling code adaptive · 64f1c21e
    Jens Axboe authored
    The previous commit introduced the hybrid sleep/poll mode. Take
    that one step further, and use the completion latencies to
    automatically sleep for half the mean completion time. This is
    a good approximation.
    This changes the 'io_poll_delay' sysfs file a bit to expose the
    various options. Depending on the value, the polling code will
    behave differently:
    -1	Never enter hybrid sleep mode
     0	Use half of the completion mean for the sleep delay
    >0	Use this specific value as the sleep delay
    Signed-off-by: default avatarJens Axboe <axboe@fb.com>
    Tested-By: default avatarStephen Bates <sbates@raithlin.com>
    Reviewed-By: default avatarStephen Bates <sbates@raithlin.com>
blk-sysfs.c 21.8 KB