Commit 6891f968 authored by Kemeng Shi's avatar Kemeng Shi Committed by Jens Axboe
Browse files

block: Correct comment for scale_cookie_change 



Default queue depth of iolatency_grp is unlimited, so we scale down
quickly(once by half) in scale_cookie_change. Remove the "subtract
1/16th" part which is not the truth and add the actual way we
scale down.

Signed-off-by: default avatarKemeng Shi <shikemeng@huawei.com>
Link: https://lore.kernel.org/r/20221018111240.22612-3-shikemeng@huawei.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent db5896e9

block/blk-iolatency.c

+4 −2
Original line number Diff line number Diff line
@@ -364,9 +364,11 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat, 
}



/*

 * Change the queue depth of the iolatency_grp.  We add/subtract 1/16th of the

 * Change the queue depth of the iolatency_grp.  We add 1/16th of the

 * queue depth at a time so we don't get wild swings and hopefully dial in to

 * fairer distribution of the overall queue depth.

 * fairer distribution of the overall queue depth.  We halve the queue depth

 * at a time so we can scale down queue depth quickly from default unlimited

 * to target.

 */

static void scale_change(struct iolatency_grp *iolat, bool up)

{