[Triton/Gluon] gemm A16w16 tune for disable amdgpu-trackers

[yanxuer-999]

Motivation

Restore two triton 3.8 performance regressions on gfx950 by cherry-picking validated tuning fixes: paged-attention GQA decode (llama3, ~-18%) and GEMM-A16W16 at N=1280/K=8192 (tracker-off VGPR spill).

Technical Details

pa_decode.py: set waves_per_eu=2 on the two v1 w_dot decode kernels (non-quant + per-token FP8), so regalloc gets the full 256-VGPR budget instead of triton 3.8's inflated 202-VGPR/occupancy-2 state (s_waitcnt lgkmcnt(0) 72→50, s_nop 36→9); v2 w_dot is intentionally left unchanged because waves_per_eu=2 there spills and regresses.

GEMM-A16W16-N=1280-K=8192.json: new gfx950 config lowering waves_per_eu (M_LEQ_32 8→4, M_LEQ_256 6→4) to remove the tracker-off VGPR spill on this shape.

Test Result

llama3 pa_decode 8B/70B/405B recovered +43/+43/+42% (deepseek-V3/wo_dot unaffected at 0%); GEMM-A16W16 N=1280 problem M sizes recovered +242/+151/+157% (M=32/192/256) with no regression on untuned shapes (<2% spread).

[github-actions]

🏷️ CI Guide

Runs automatically on every PR:

• ✅ Pre-checks (submodule verification, code formatting)
• ✅ Aiter op tests (gfx942 + gfx950)
• ✅ Triton tests on MI35X (only when aiter/ops/triton/** or related paths are changed)

Extended tests (opt-in via labels):

Label	Tests
ci:gfx1250-ffm-triton	Run the five-shard gfx1250 FFM Triton test suite
ci:triton-300x	Run an additional Triton test job on MI300X in PRs; main branch always runs both MI35X and MI300X
multigpu	Aiter multi-GPU tests on the 8-GPU runner
ci:sglang	SGLang integration tests: DeepSeek-R1-MXFP4 accuracy, Qwen 3.5 accuracy
ci:atom	ATOM benchmark: DeepSeek-R1-0528, GPT-OSS-120B
ci:atom_full	ATOM accuracy suite for PR and main models from ATOM models_accuracy.json
ci:vllm	vLLM benchmark: GPT-OSS-120B, DeepSeek-R1-0528, Kimi-K2.5
ci:all	All standard extended tests (excludes ci:atom_full)

Only add ci:atom_full for FlyDSL or Triton upgrades.
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