[Mesa-dev] Time to merge threaded GL dispatch? (aka glthread)

[Marek Olšák]

On Fri, Feb 10, 2017 at 12:48 PM, Edward O'Callaghan
<funfunctor at folklore1984.net> wrote:
>
>
> On 02/10/2017 10:36 PM, Marek Olšák wrote:
>> On Fri, Feb 10, 2017 at 12:26 PM, Edward O'Callaghan
>> <funfunctor at folklore1984.net> wrote:
>>>
>>>
>>> On 02/08/2017 09:13 AM, Timothy Arceri wrote:
>>>> On Tue, 2017-02-07 at 10:56 +0100, Marek Olšák wrote:
>>>>> On Tue, Feb 7, 2017 at 2:57 AM, Kenneth Graunke <kenneth at whitecape.or
>>>>> g> wrote:
>>>>>> On Monday, February 6, 2017 8:54:40 PM PST Marek Olšák wrote:
>>>>>>> On Mon, Feb 6, 2017 at 8:20 PM, Ernst Sjöstrand <ernstp at gmail.com
>>>>>>>> wrote:
>>>>>>>> FYI glmark2 segfaults with mesa_glthread=true. Expected that
>>>>>>>> some programs
>>>>>>>> will segfault?
>>>>>>>
>>>>>>> Yes, even segfaults are expected with mesa_glthread=true.
>>>>>>>
>>>>>>> Marek
>>>>>>
>>>>>> Would it make sense to be crash-free or even regression-free on at
>>>>>> least Piglit, before merging?  (Or are we there already?)
>>>>>
>>>>> It's not necessary. glthread is disabled by default. Nobody has
>>>>> tested
>>>>> piglit with glthread. That will follow after it's been merged, or
>>>>> never if it's never merged.
>>>>
>>>> I've been trying to land shader-cache patches that actually do pass
>>>> piglit for over a year with the same reasoning that it will be disable
>>>> by default and can only be improved with testing I can't possibly do on
>>>> my own.
>>>>
>>>> Although I have no objections to this being merged I'll be extremely
>>>> frustrated if this is allowed to be merged known to not even pass
>>>> piglit while I've wasted countless hours rebasing shader cache over
>>>> many months.
>>>>
>>>
>>> Regardless of all the chatter on this thread in and around GL dispatch,
>>> which I agree poses significant challenges to get into something 'ideal'
>>> - which is hard to define for something like this..
>>>
>>> I think Timothy makes a really fair and just case here; in that, could
>>> we perhaps prioritize getting the shader cache stuff in before
>>> attempting GL dispatch? I think this both morally and technically the
>>> right thing to do in my humble opinion.
>>
>> There is a small difference. The shader cache is expected to be
>> enabled by default, so there is a certain level of quality required.
>
> Hey Marek,
>
> I am under the impression that it being enabled by default isn't a hard
> requirement for it to be merged. Maybe Timothy can weigh in on it when
> he is online?

There is no official hard requirement. Everything is a judgement call
based on circumstances.

Marek