Re: [PATCH v2 2/3] block: Correct comment for scale_cookie_change

From: Kemeng Shi
Date: Tue Nov 01 2022 - 05:40:13 EST


Friendly ping.

on 10/18/2022 7:12 PM, Kemeng Shi wrote:
> 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: Kemeng Shi <shikemeng@xxxxxxxxxx>
> ---
> block/blk-iolatency.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index b24d7b788ba3..2c574f98c8d1 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -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)
> {
>

--
Best wishes
Kemeng Shi