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

[Michel Dänzer]

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.


-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer