[Mesa-dev] [RFC PATCH] gallium: add a common uploader to pipe_context

[Brian Paul]

On 02/03/2017 02:41 PM, Marek Olšák wrote:
> On Fri, Feb 3, 2017 at 9:45 PM, Brian Paul <brianp at vmware.com> wrote:
>> On 02/01/2017 02:23 PM, Brian Paul wrote:
>>>
>>> On 01/27/2017 04:00 AM, Marek Olšák wrote:
>>>>
>>>> On Fri, Jan 27, 2017 at 10:05 AM, Nicolai Hähnle <nhaehnle at gmail.com>
>>>> wrote:
>>>>>
>>>>> On 27.01.2017 00:51, Marek Olšák wrote:
>>>>>>
>>>>>>
>>>>>> From: Marek Olšák <marek.olsak at amd.com>
>>>>>>
>>>>>> For lower memory usage and more efficient updates of the buffer
>>>>>> residency
>>>>>> list. (e.g. if drivers keep seeing the same buffer for many consecutive
>>>>>> "add" calls, the calls can be turned into no-ops trivially)
>>>>>
>>>>>
>>>>>
>>>>> This makes sense to me, but how are you planning to deal with the bind
>>>>> flags? They are currently set differently for different upload mgrs. We
>>>>> should probably do away with them entirely anyway.
>>>>
>>>>
>>>> Drivers can set the bind flags they need. Some drivers will set all 3
>>>> bind flags. Other drivers don't have to set any.
>>>
>>>
>>> I need to look into this part more closely.  I think we may have trouble
>>> mixing constants with index/vertex data in our VMware driver...
>>
>>
>> Marek,
>>
>> Your patch series, as-is, did indeed cause trouble with our VMware driver.
>> We need to keep constants in a separate buffer.
>>
>> The good news is I don't think this is a huge problem and I've updated (a
>> subset of) your patches to accommodate both your needs and ours.
>>
>> The basic idea is to add a pipe_context::get_stream_uploader() hook that
>> allows drivers to use just one or separate uploaders for
>> vertex/index/constant data.  Plus, I added a
>> pipe_context::unmap_stream_uploaders() helper, but this isn't strictly
>> necessary.
>>
>> WIP patch attached (only lightly tested).  Let me know what you think.
>
> Can we simply add these 2 fields into pipe_context instead of the callback?
>
> pipe_context::stream_uploader // vertex + index
> pipe_context::const_uploader

Yeah, that might work too.  Though, now I have to test the case of 
vertex data and index data being in the same VBO.  We may need three 
uploader pointers...

-Brian