From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kemeng Shi Subject: Re: [PATCH v2 2/3] block: Correct comment for scale_cookie_change Date: Tue, 1 Nov 2022 17:38:34 +0800 Message-ID: References: <20221018111240.22612-1-shikemeng@huawei.com> <20221018111240.22612-3-shikemeng@huawei.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20221018111240.22612-3-shikemeng-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, josef-DigfWCa+lFGyeJad7bwFQA@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org 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 > --- > 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