Message-ID: <3ba1adc6-4fb4-036c-8eca-91f549471c49@kernel.dk>
Date:   Fri, 27 Jan 2023 13:10:08 -0700
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Subject: Re: [PATCH] block: Default to build the BFQ I/O scheduler
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To:     Ulf Hansson <ulf.hansson@linaro.org>
Cc:     linux-block@vger.kernel.org,
        Paolo Valente <paolo.valente@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        linux-kernel@vger.kernel.org
References: <20230127154339.157460-1-ulf.hansson@linaro.org>
 <5743fb1b-eb4b-d169-a467-ee618bcd75f5@kernel.dk>
 <CAPDyKFqFrB4h21F0901nBp-mpiP70nObOrCpRA0ZRfOD_kD5ug@mail.gmail.com>
From:   Jens Axboe <axboe@kernel.dk>
In-Reply-To: <CAPDyKFqFrB4h21F0901nBp-mpiP70nObOrCpRA0ZRfOD_kD5ug@mail.gmail.com>
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On 1/27/23 8:58 AM, Ulf Hansson wrote:
> On Fri, 27 Jan 2023 at 16:48, Jens Axboe <axboe@kernel.dk> wrote:
>>
>> On 1/27/23 8:43 AM, Ulf Hansson wrote:
>>> Today BFQ is widely used and it's also the default choice for some of the
>>> single-queue-based storage devices. Therefore, let's make it more
>>> convenient to build it as default, along with the other I/O schedulers.
>>>
>>> Let's also build the cgroup support for BFQ as default, as it's likely that
>>> it's wanted too, assuming CONFIG_BLK_CGROUP is also set, of course.
>>
>> This won't make much of a difference, when the symbols are already in
>> the .config. So let's please not. It may be a 'y' for you by default,
>> but for lots of others it is not. Don't impose it on folks.
> 
> This isn't about folkz, but HW. :-)

Is it everybody? No, it's a subset. Everybody adding a new driver wants
to default to y/m, and it's almost always wrong.

> I was thinking that it makes sense for the similar reason to why kyber
> and deadline are being built as default. Or are there any particular
> other reasons to why we build those in as default, but not BFQ?

deadline arguably makes sense as it's simple, and we should have one
default scheduler. kyber probably does not need to be default y. But
at least that one doesn't pull in other dependencies.

-- 
Jens Axboe