[Mesa-dev] r600/sb loop issue

[Dave Airlie]

On 16 December 2014 at 08:59, Vadim Girlin <vadimgirlin at gmail.com> wrote:
> On 12/16/2014 01:30 AM, Dave Airlie wrote:
>>>>>
>>>>>
>>>>>
>>>>> New patch is attached, the only difference is in the sb_sched.cpp (it
>>>>> disables copy coalescing for some "unsafe" cases, so it may leave more
>>>>> MOVs
>>>>> than previously, but I don't think there will be any noticeable effect
>>>>> on
>>>>> performance).
>>>>>
>>>>> So far I don't see any problems with it, but I don't have many GL apps
>>>>> on
>>>>> the test machine. At least lightsmark and unigine demos work for me.
>>>>>
>>>>
>>>> Based on my limited understanding of the code:
>>>>
>>>> Acked-by: Alex Deucher <alexander.deucher at amd.com>
>>>
>>>
>>>
>>> Alex, thanks for the review, I understand you wanted it to get into mesa
>>> release, but it really needs careful testing with more apps, so far I
>>> hoped
>>> Dave would do it as long as he's looking into these issues anyway. In
>>> theory
>>> I can also install steam on the test machine and some games, it just
>>> needs
>>> the time and I'm not sure if I'll find it, so far my main job is
>>> sufficient
>>> to make me pretty tired.
>>>
>>> Current scheduler in SB is very fragile after adding handling for all
>>> special cases discovered during initial debugging etc, I said since the
>>> very
>>> beginning that I'd like to rewrite it, if only I had time. So any change
>>> like this can potentially break some apps even if piglit passes, and I'm
>>> not
>>> ready to take responsibility for that if I commit it myself, I just don't
>>> have time to deal with all possible consequences on all supported chips.
>>>
>>> If you think it's ok, just push this patch (it requires revert of the
>>> previous Dave's commit 7b0067d2). I'm really sorry that I can't do more
>>> to
>>> help with it.
>>
>>
>> Myself and Glenn are looking at it, Glenn noticed a piglit regression
>> from this yesterday, I'll reproduce today and take a look.
>
>
> Hi, Dave & Glenn,
>
> Thanks for looking into it. FWIW, when I worked on it I've ran piglit's
> quick tests and didn't see any regressions on evergreen (juniper 5750).
> There were some failed tests in some piglit runs, but AFAIU they were just
> random.

Turns out we had a pre-existing fail that we noticed, not a regression.

I'm going to push this, since its better than what is there, we can
see if some public testing notices any big issues also.

Dave.