(In reply to Lorenzo Bona from comment #18)
> Reverting this commit 
> 
> http://cgit.freedesktop.org/mesa/mesa/commit/src/gallium/drivers/radeon/
> r600_buffer_common.c?id=7b4276d7acf2e0f77044cb50caa6ad936fa78786
> 
> helps a little bit.
> 
> But it's not as fluid as on 3.16rc6 kernel.

 That same mesa used with 3.16rc6 and drm-fixes-3.19? Does those two kernels
have same/similar performance (without that large drop), but just
drm-fixes-3.19 is not so fluid like when 3.16rc6 kernel is used?

 And you builded that mesa now with -mtune=native for both CFLAGS and CXXFLAGS?

 Asking all those because i don't have those sttuter problems with 3.19 kernel
and that reverted but that is on APU... than it seems to me like only dedicated
cards are affected.