[Mesa-dev] Mesa (master): 29 new commits

[Nicolai Hähnle]

On 22.04.2016 12:29, Nicolai Hähnle wrote:
> On 20.04.2016 23:02, Michel Dänzer wrote:
>> On 21.04.2016 02:42, Marek Olšák wrote:
>>> On Thu, Apr 14, 2016 at 9:29 AM, Michel Dänzer <michel at daenzer.net>
>>> wrote:
>>>> On 14.04.2016 11:37, Michel Dänzer wrote:
>>>>> On 12.04.2016 21:33, Marek =?UNKNOWN?B?T2zFocOhaw==?= wrote:
>>>>>>
>>>>>> URL:
>>>>>> http://cgit.freedesktop.org/mesa/mesa/commit/?id=5a4b74d1ba2c156766a7a5dbfef099c7db5d6694
>>>>>>
>>>>>> Author: Marek Olšák <marek.olsak at amd.com>
>>>>>> Date:   Mon Apr 11 19:56:07 2016 +0200
>>>>>>
>>>>>>      gallium/radeon: relax requirements on VRAM placements on APUs
>>>>>
>>>>> This change caused a bunch of ARB_shader_load_image_store piglit tests
>>>>> to fail on my Kaveri, see some examples below. The incorrect values
>>>>> seem consistent.
>>>>>
>>>>> I suppose some buffers end up in GTT instead of VRAM with this
>>>>> change, but I'm not sure how that could cause problems. Any ideas?
>>>>
>>>> Also, with the code modified to use GTT only for everything but
>>>> (potential) scanout buffers, the performance of Unigine Valley and the
>>>> Unreal Engine 4 Elemental demo is reduced by about 30%. So the premise
>>>> that GTT is about as fast as VRAM doesn't seem to hold true in practice
>>>> (at least with Kaveri and presumably other (pre-)CIK APUs; maybe it's
>>>> better with Carrizo and newer), which means that this change may cause
>>>> performance of long-running processes to drop significantly over time.
>>>>
>>>> Given all these issues, I'm afraid it may be better to revert this
>>>> change for now, until we have a better plan for dealing with this.
>>>
>>> Assuming you use the radeon kernel driver and you are not busy, would
>>> you please check whether the performance is lower on amdgpu as well?
>>
>> I am using the radeon driver, but also quite busy. Nicolai, can you try
>> it on your Carrizo?
>
> I don't see any difference on Unigine Valley with my Carrizo (512MB of
> VRAM).

I have learned an important lesson today: the Phoronix Test Suite runner 
eats my environment variables (and possibly babies?). So my earlier 
tests were for nothing.

In reality, Unigine Valley gains about 30% frame rate with the VRAM_GTT 
placement.

Nicolai