[PATCH 4/4] drm/mm: Remove DRM_MM_SEARCH_BEST

[Alex Deucher]

On Tue, Nov 4, 2014 at 3:47 AM, Michel Dänzer <michel at daenzer.net> wrote:
> On 01.11.2014 03:10, Alex Deucher wrote:
>>
>> On Thu, Oct 30, 2014 at 4:36 AM, Michel Dänzer <michel at daenzer.net> wrote:
>>>
>>> From: Michel Dänzer <michel.daenzer at amd.com>
>>>
>>> In the words of Daniel Vetter:
>>>
>>> «I think SEARCH_BEST is pretty much always a bad idea - it rips apart
>>> allocations from the same execbuf, and usually those get recycled around
>>> the same time. Which means you'll just fragment your mm even more if you
>>> try to find the best hole instead of just picking one and the stuffing
>>> the entire execbuf into it. So imo we might as well just kill it.»
>>>
>>> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
>>
>>
>> Applied this series to my -next tree.
>
>
> Thanks. Unfortunately, the removal of DRM_MM_SEARCH_BEST caused performance
> regressions, presumably due to excessive eviction from VRAM, see
> https://bugs.freedesktop.org/show_bug.cgi?id=84662#c49 . I can reproduce a
> significant bad effect with the UE4 Elemental demo on my development
> machine. Please drop this patch.
>
> The original patches 4 & 5 have the same effect, so they shouldn't be
> applied either. Maybe we can try this again once TTM is using the MM scan
> roaster for eviction.
>

I dropped this patch.

Thanks,

Alex