[Don't Merge] Isolate MLA failure: CK pre-#7331 (do not merge)

[DDEle]

Why

PR #3150 sees a test_mla_persistent.py (shard 5/2 MI35X) failure that's hard to attribute. PR #3150's own aiter code changes only touch FMHA BWD; CK is also bumped from 33b62ed0 → 83566edb0 (10 CK PRs including #7331).

This draft bumps CK to 4d852e80f (= PR #6983, the commit immediately before #7331) and leaves everything else identical to main. CI here exercises the same 9 CK PRs as #3150 minus only #7331's FMHA BWD async-prepare changes.

Outcome interpretation

• If shard 5/2 MLA fails here too → cause is one of the other 9 CK PRs (or pre-existing flakiness on MI35X). [CK_TILE] FMHA BWD: stream-async workspace prepare for group mode #3150 is innocent.
• If shard 5/2 MLA passes here → would need to investigate #7331 further (very unlikely since #7331 only touches FMHA BWD launcher code paths that MLA does not call).

Not for merge

Pure CI diagnostic; will be closed once we have the result.

[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:triton-300x	Run an additional Triton test job on MI300X in PRs; main branch always runs both MI35X and MI300X
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.
Add labels via the sidebar or gh pr edit 3246 --add-label <label>

[Copilot]

Pull request overview

Pins the composable_kernel submodule to the commit immediately preceding ROCm/rocm-libraries#7331 to help bisect and attribute the observed test_mla_persistent.py failure (MI35X shard 5/2) without introducing any aiter-side code changes.

Changes:

• Updates 3rdparty/composable_kernel submodule revision to 4d852e80f (pre-#7331) for CI/bisect isolation.
• Leaves the rest of the repository identical to main to keep the experiment controlled.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.