From: Kemeng Shi <shikemeng@huawei.com>
To: <tj@kernel.org>, <josef@toxicpanda.com>, <axboe@kernel.dk>
Cc: <cgroups@vger.kernel.org>, <linux-block@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 2/3] block: Correct comment for scale_cookie_change
Date: Tue, 1 Nov 2022 17:38:34 +0800 [thread overview]
Message-ID: <d92907aa-2e57-dd68-c6ce-b8065cd25770@huawei.com> (raw)
In-Reply-To: <20221018111240.22612-3-shikemeng@huawei.com>
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@huawei.com>
> ---
> 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
next prev parent reply other threads:[~2022-11-01 9:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-18 11:12 [PATCH v2 0/3] A few cleanup patches for blk-iolatency.c Kemeng Shi
2022-10-18 11:12 ` [PATCH v2 1/3] block: Remove redundant parent blkcg_gp check in check_scale_change Kemeng Shi
2022-10-18 11:12 ` [PATCH v2 2/3] block: Correct comment for scale_cookie_change Kemeng Shi
2022-11-01 9:38 ` Kemeng Shi [this message]
2022-11-02 14:11 ` Josef Bacik
2022-10-18 11:12 ` [PATCH v2 3/3] block: Replace struct rq_depth with unsigned int in struct iolatency_grp Kemeng Shi
2022-11-01 14:17 ` [PATCH v2 0/3] A few cleanup patches for blk-iolatency.c Jens Axboe
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