Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging

From: Benjamin Gaignard <benjamin.gaignard@linaro.org>
To: "Mark Brown" <broonie@kernel.org>,
	"Michal Hocko" <mhocko@kernel.org>,
	"Laura Abbott" <labbott@redhat.com>,
	"Sumit Semwal" <sumit.semwal@linaro.org>,
	"Riley Andrews" <riandrews@android.com>,
	"Arve Hjønnevåg" <arve@android.com>,
	"Rom Lemarchand" <romlem@google.com>,
	devel@driverdev.osuosl.org,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	"linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	linux-arm-kernel@lists.infradead.org,
	"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"Brian Starkey" <brian.starkey@arm.com>,
	"Daniel Vetter" <daniel.vetter@intel.com>,
	"Benjamin Gaignard" <benjamin.gaignard@linaro.org>,
	linux-mm@kvack.org
Subject: Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging
Date: Thu, 9 Mar 2017 11:00:39 +0100	[thread overview]
Message-ID: <CA+M3ks77Am3Fx-ZNmgeM5tCqdM7SzV7rby4Es-p2F2aOhUco9g@mail.gmail.com> (raw)
In-Reply-To: <20170306160437.sf7bksorlnw7u372@phenom.ffwll.local>

2017-03-06 17:04 GMT+01:00 Daniel Vetter <daniel@ffwll.ch>:
> On Mon, Mar 06, 2017 at 11:58:05AM +0100, Mark Brown wrote:
>> On Mon, Mar 06, 2017 at 11:40:41AM +0100, Daniel Vetter wrote:
>>
>> > No one gave a thing about android in upstream, so Greg KH just dumped it
>> > all into staging/android/. We've discussed ION a bunch of times, recorded
>> > anything we'd like to fix in staging/android/TODO, and Laura's patch
>> > series here addresses a big chunk of that.
>>
>> > This is pretty much the same approach we (gpu folks) used to de-stage the
>> > syncpt stuff.
>>
>> Well, there's also the fact that quite a few people have issues with the
>> design (like Laurent).  It seems like a lot of them have either got more
>> comfortable with it over time, or at least not managed to come up with
>> any better ideas in the meantime.
>
> See the TODO, it has everything a really big group (look at the patch for
> the full Cc: list) figured needs to be improved at LPC 2015. We don't just
> merge stuff because merging stuff is fun :-)
>
> Laurent was even in that group ...
> -Daniel

For me those patches are going in the right direction.

I still have few questions:
- since alignment management has been remove from ion-core, should it
be also removed from ioctl structure ?
- can you we ride off ion_handle (at least in userland) and only
export a dma-buf descriptor ?

In the future how can we add new heaps ?
Some platforms have very specific memory allocation
requirements (just have a look in the number of gem custom allocator in drm)
Do you plan to add heap type/mask for each ?

Benjamin

> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

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