* Ubuntu 18.04
* Unity / compiz desktop
* X server git version with modifiers enabled
* drm-tip kernel v4.19 or v4.20
* Mesa git version
Between following Mesa commits:
* 2018-12-13 17:49:48 9ebc00f32e: i965: Enable nir_opt_idiv_const for 32 and 64-bit integers
* 2018-12-14 17:40:27 5c454661c6: i965/gen9: Add workarounds for object preemption
Unigine Heaven 4.0 and Valley 1.0 performance regressed.
On SKL GT4e, perf drop is:
- 2% in Heaven (high quality, tessellation enabled, no MSAA, fullscreen)
- 1% in Valley
On slower machines, drop is somewhat smaller. Drop is GEN9+ specific, or at least it's not visible on older platforms. There may be some minuscule regression also in heavier GfxBench tests, but it's too smaller to say for sure.
Something on the kernel side in drm-tip git improved Heaven performance by similar amount it dropped with Mesa in December. That didn't affect Valley though.