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Date: Tue, 30 Jan 2024 22:53:45 +0900
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Subject: Re: [PATCHv5 1/1] block: introduce content activity based ioprio
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To: Zhaoyang Huang <huangzhaoyang@gmail.com>
Cc: "zhaoyang.huang" <zhaoyang.huang@unisoc.com>,
 Andrew Morton <akpm@linux-foundation.org>, Jens Axboe <axboe@kernel.dk>,
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From: Damien Le Moal <dlemoal@kernel.org>
Organization: Western Digital Research
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On 1/30/24 22:28, Zhaoyang Huang wrote:
>> That information does not belong to the ioprio. And which scheduler acts on a
>> number of pages anyway ? The scheduler sees requests and BIOs. It can determine
>> the number of pages they have if that is an information it needs to make
>> scheduling decisison. Using ioprio to pass that information down is a dirty hack.
> No. IO scheduler acts on IOPRIO_CLASS which is transferred from the
> page's activity by the current method. I will implement another
> version of iterating pages before submit_bio and feed back to the list

Then why are you modifying the ioprio user API to add the 7 bits of activity ?
If the scheduler only needs the priority class, then only set that and do not
touch the user facing API.

-- 
Damien Le Moal
Western Digital Research