Armagetron: Mesa ps3.262's -13%, the lost CPU/GPU overlap (2026-10-17)

Symptom. Mesa ps3.262 (0019-0025, fewer words per draw) sped up every game of the suite by 11-24%, except Armagetron: its playback went from 60 fps HUD median on ps3.246 (59 and 61 in the same boot, batch 2026-10-17-mesa-246-control) to 52.5 (-13%, batch 2026-10-17-mesa-262), and 50 on ps3.282.

Evidence. Not 0020’s texture invalidation: texinv gave 52 (batch 2026-10-17-mesa-262-repeats). On ps3.282 (batch 2026-10-17-mesa-282-armagetron) the switches told: with relocations back on, or a fixed kick every 50 or 100 draws (kick50, kick100), it was 60.5 again. In the first profile (Mesa ps3.223) “other kernel” was 21% of its CPU.

Cause. 0019 dropped the submissions the relocation limit used to force mid-frame. Armagetron’s frames are small enough that the whole frame then reached the GPU only at the swap: the CPU and the GPU no longer overlapped.

Fix. Mesa 0027’s adaptive submission (ps3.299) kicks the push buffer as the frame grows: 61.5 (batch 2026-10-17-mesa-299). A fixed kick100 was rejected, because it cost X-Moto 9%.