Re: [RFC][PATCH v6 0/7] Generic page pool & deferred freeing for system dmabuf heap

From: John Stultz
Date: Fri Feb 05 2021 - 16:01:40 EST


On Fri, Feb 5, 2021 at 2:36 AM Christian König <christian.koenig@xxxxxxx> wrote:
> Am 05.02.21 um 09:06 schrieb John Stultz:
> > Input would be greatly appreciated. Testing as well, as I don't
> > have any development hardware that utilizes the ttm pool.
>
> We can easily do the testing and the general idea sounds solid to me.
>

Thanks so much again for the feedback!

> I see three major things we need to clean up here.
> 1. The licensing, you are moving from BSD/MIT to GPL2.

Yea, this may be sticky, as it's not just code re-used from one dual
licensed file, but combination of GPL2 work, so advice here would be
appreciated.

> 2. Don't add any new overhead to the TTM pool, especially allocating a
> private object per page is a no-go.

This will need some more series rework to solve. I've got some ideas,
but we'll see if they work.

> 3. What are you doing with the reclaim stuff and why?

As I mentioned, it's a holdover from earlier code, and I'm happy to
drop it and defer to other accounting/stats discussions that are
ongoing.

> 4. Keeping the documentation would be nice to have.

True. I didn't spend much time with documentation, as I worried folks
may have disagreed with the whole approach. I'll work to improve it
for the next go around.

Thanks so much again for the review and feedback! I really appreciate
your time here.
-john