[Mesa-dev] [Patch] Sharing flags should disable tiling

[Chad Versace]

On 08/12/2013 03:15 PM, Stéphane Marchesin wrote:
> On Mon, Aug 12, 2013 at 3:05 PM, Marek Olšák <maraeo at gmail.com> wrote:
>> On Mon, Aug 12, 2013 at 11:36 PM, Stéphane Marchesin
>> <stephane.marchesin at gmail.com> wrote:
>>>> Other than hybrid systems (of which
>>>> there are none with i915 graphics), is there any case where
>>>> __DRI_IMAGE_USE_SHARE can occur?
>>>
>>> You could do interesting things like cross-process sharing with it. I
>>> think it's worth doing it, no matter what. It's easy to pick up now,
>>> and hard to fix up later.
>>
>> Cross-process sharing is mandatory already and exposed via
>> resource_from_handle and resource_get_handle. I don't think this is
>> useful for cross-process sharing anyway, because it disables tiling.
>>
>
> Well, for Chrome we're thinking of using it. If one end can map linear
> memory and write texture data to it from the CPU, and the other end
> can use it as a GL texture, then we have a zero copy cross-process
> texture upload. I realize it's not your normal use case, but... :)

Stéphane, have you considered using EGL_EXT_dma_buf_import with
GL_OES_EGL_image_external for Chrome texture sharing? It seems
like a good fit for what Chrome is doing: sharing non-mipmapped
2d texture memory. Both extensions recently landed on master for
i965.

On that note, do you have any interest in moving Chrome/Intel
awaw from GLX to EGL? Some people on the Intel Media team have
been discussing a desire to do that for some of the media
components.