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From: Zhaoyang Huang <huangzhaoyang@gmail.com>
Date: Fri, 26 Jan 2024 09:14:30 +0800
Message-ID: <CAGWkznHdE_zJ1pnxf-0-D3M=8aBwn-gFNte333WbKPioygGdLA@mail.gmail.com>
Subject: Re: [PATCHv3 1/1] block: introduce content activity based ioprio
To: Damien Le Moal <dlemoal@kernel.org>
Cc: "zhaoyang.huang" <zhaoyang.huang@unisoc.com>, Andrew Morton <akpm@linux-foundation.org>, 
	Jens Axboe <axboe@kernel.dk>, Yu Zhao <yuzhao@google.com>, 
	Niklas Cassel <niklas.cassel@wdc.com>, "Martin K . Petersen" <martin.petersen@oracle.com>, 
	Hannes Reinecke <hare@suse.de>, Linus Walleij <linus.walleij@linaro.org>, linux-mm@kvack.org, 
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, 
	steve.kang@unisoc.com
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On Thu, Jan 25, 2024 at 6:10=E2=80=AFPM Zhaoyang Huang <huangzhaoyang@gmail=
com> wrote:
>
> On Thu, Jan 25, 2024 at 5:54=E2=80=AFPM Damien Le Moal <dlemoal@kernel.or=
g> wrote:
> >
> > On 1/25/24 18:37, Zhaoyang Huang wrote:
> > > Actually, the activity information comes from page's history (recorde=
d
> > > at page cache's slot) instead of user space in step(1) and can be
> > > associate with bio in step(2) or iterate the bio in step(3)
> > > page fault(or vfs)(1)
> > > |
> > > alloc_pages
> > > |
> > > add_page_to_pagecache(get the page's activity information)
> > > |
> > > fs_readpage
> > > |
> > > bio_add_page(2)
> > > |
> >
> > set your prio here. No change to the block layer needed. That is FS lan=
d.
> Yes, that is what I suggested in patchv3 which keeps the block layer
> clean by introducing a set of helper functions which wrap up the
> activity things for FS utilization.
Maybe I misunderstand Damien's opinion which suggests iterating the
bio->bvec here via a new API. I think it is more costly than counting
activities when adding pages to bio and need more modifications on
each fs.
> >
> > > submit_bio(3)
> >
> >
> > --
> > Damien Le Moal
> > Western Digital Research
> >