Re: [PATCH v7 0/3] FDP and per-io hints

[Jens Axboe <axboe@kernel.dk>]

On 10/2/24 9:13 AM, Christoph Hellwig wrote:
> On Wed, Oct 02, 2024 at 09:03:22AM -0600, Jens Axboe wrote:
>>> The previous stream separation approach made total sense, but just
>>> needed a fair amount of work.  But it closely matches how things work
>>> at the hardware and file system level, so it was the right approach.
>>
>> What am I missing that makes this effort that different from streams?
>> Both are a lifetime hint.
> 
> A stream has a lot less strings attached.  But hey, don't make me
> argue for streams - you pushed the API in despite reservations back
> then, and we've learned a lot since.

Hah, I remember arguing for it back then! It was just a pain to use, but
thankfully we could kill it when devices didn't materialize with a
quality of implementation that made them useful. And then we just yanked
it. Nothing is forever, and particularly hints is something that can
always be ignored. Same for this.

>>> Suddenly dropping that and ignoring all comments really feels like
>>> someone urgently needs to pull a marketing stunt here.
>>
>> I think someone is just trying to finally get this feature in, so it
>> can get used by customers, after many months of fairly unproductive
>> discussion.
> 
> Well, he finally started on the right approach and gave it up after the
> first round of feedback.  That's just a bit weird.

I'm a big fan of keep-it-simple-stupid, and then you can improve it down
the line. I think the simple approach stands just fine alone.

-- 
Jens Axboe