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References: <20240205055705.7078-1-zhaoyang.huang@unisoc.com> <ZcCJbtX3xwBRCqYJ@casper.infradead.org>
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From: Zhaoyang Huang <huangzhaoyang@gmail.com>
Date: Mon, 5 Feb 2024 15:13:15 +0800
Message-ID: <CAGWkznF2EeLFyKqDP1EMgKz333TyS-pA8+9-KdDLTuZyD1C==w@mail.gmail.com>
Subject: Re: [PATCHv7 1/1] block: introduce content activity based ioprio
To: Matthew Wilcox <willy@infradead.org>
Cc: "zhaoyang.huang" <zhaoyang.huang@unisoc.com>, Jens Axboe <axboe@kernel.dk>, 
	Yu Zhao <yuzhao@google.com>, linux-block@vger.kernel.org, 
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, 
	steve.kang@unisoc.com
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On Mon, Feb 5, 2024 at 3:08=E2=80=AFPM Matthew Wilcox <willy@infradead.org>=
 wrote:
>
> On Mon, Feb 05, 2024 at 01:57:05PM +0800, zhaoyang.huang wrote:
> > +/*
> > + * bio_set_active_ioprio() is helper function for fs to adjust the bio=
's ioprio via
> > + * calculating the content's activity which measured from MGLRU.
> > + * The file system should call this function before submit_bio for the=
 buffered
> > + * read/write/sync.
> > + */
> > +#ifdef CONFIG_BLK_CONT_ACT_BASED_IOPRIO
> > +void bio_set_active_ioprio(struct bio *bio)
> > +{
> > +     struct bio_vec bv;
> > +     struct bvec_iter iter;
> > +     struct page *page;
> > +     int class, level, hint;
> > +     int activity =3D 0;
> > +     int cnt =3D 0;
> > +
> > +     class =3D IOPRIO_PRIO_CLASS(bio->bi_ioprio);
> > +     level =3D IOPRIO_PRIO_LEVEL(bio->bi_ioprio);
> > +     hint =3D IOPRIO_PRIO_HINT(bio->bi_ioprio);
> > +     /*apply legacy ioprio policy on RT task*/
> > +     if (task_is_realtime(current)) {
> > +             bio->bi_ioprio =3D IOPRIO_PRIO_VALUE_HINT(IOPRIO_CLASS_RT=
, level, hint);
> > +             return;
> > +     }
> > +     bio_for_each_bvec(bv, bio, iter) {
> > +             page =3D bv.bv_page;
>
> I gave you the prototype:
>
> : No, stop this.  What the filesystem needs to do is not
> : s/bio_add_folio/act_bio_add_folio/.  There needs to be an API to set th=
e
> : bio prio; something like:
> :
> :         bio_set_active_prio(bio, folio);
>
> Do not iterate over the bio.  Use the folio provided to set the prio.
ok. I should miss the above information. I will update them in the next ver=
sion
>
> Or is there some reason this doesn't work?