[ROCM] [FEAT] Integrate Aiter hipBLASLt GEMM online tuning by hanlin12-AMD · Pull Request #40426 · vllm-project/vllm

hanlin12-AMD · 2026-04-21T03:07:00Z

Enable ROCm AITER hipBLASLt online tuning via a vLLM env var, and add ROCm tests covering the online-tuning flow and kernel gating behavior.

Purpose

This PR adds support for enabling hipBLASLt online tuning in vLLM through VLLM_ROCM_USE_AITER_LINEAR_HIPBMM, which forwards to HIP_ONLINE_TUNING=1 early in ROCm
platform initialization so tuning is available before hipBLASLt is initialized.

It also tightens the gating error message produced by AiterHipbMMPerTokenFp8ScaledMMLinearKernel.is_supported() to a single, Oxford-comma-formatted line listing
all three required flags (VLLM_ROCM_USE_AITER, VLLM_ROCM_USE_AITER_LINEAR, VLLM_ROCM_USE_AITER_LINEAR_HIPBMM), so users hitting the gate get a clear,
actionable hint.

This PR also adds ROCm/AITER test coverage for:

heuristic hipb_mm execution
explicit solution selection
CSV cache population for tuned shapes
forwarding from VLLM_ROCM_USE_AITER_LINEAR_HIPBMM to HIP_ONLINE_TUNING
FP8 row-wise scaled GEMM behavior
force-flag gating for the AITER hipb_mm linear kernel
numerical accuracy of the AITER hipb_mm FP8 kernel against a dequantized fp32 reference, isolating layout / scale / bias bugs from inherent FP8 quantization
noise
weight-shuffling in process_weights_after_loading (verifies the stored weight is the shuffled [K, N] view and the weight-scale is .t().contiguous())
can_implement rejection paths (non-bf16 output dtype, non per-token/per-channel scaling, and N < 16 / non-16-aligned shapes)

Test Plan

VLLM_ROCM_USE_AITER=1 VLLM_ROCM_USE_AITER_LINEAR=1 VLLM_ROCM_USE_AITER_LINEAR_HIPBMM=1 python -m pytest tests/rocm/aiter/test_aiter_hipb_mm_linear_kernel.py -v

Test Result

Qwen3-32B result before and after hipBLASLt online tuning

Qwen3-32B score before and after hipBLASLt online tuning

Documentation update is not required for this change.

Essential Elements of an Effective PR Description Checklist

The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
The test plan, such as providing test command.
The test results, such as pasting the results comparison before and after, or e2e results
(Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.

Signed-off-by: hanlin12 <hanlin12@amd.com>

Signed-off-by: Han Lin <hanlin12@amd.com>

Signed-off-by: hanlin12 <hanlin12@amd.com>

claude

Claude Code Review

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github-actions · 2026-04-21T03:07:08Z

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mergify · 2026-04-21T03:07:35Z

⚠️ The sha of the head commit of this PR conflicts with #37146. Mergify cannot evaluate rules on this PR. Once #37146 is merged or closed, Mergify will resume processing this PR. ⚠️

gemini-code-assist

Code Review

This pull request introduces support for hipBLASLt online tuning on ROCm via the aiter library, specifically adding the AiterHipbMMPerTokenFp8ScaledMMLinearKernel for FP8 GEMM. The implementation includes new environment variables, custom op registrations, and a comprehensive test suite. Reviewers identified a critical bug in the kernel implementation where the weight tensor was incorrectly transposed, which would lead to incorrect results. Additionally, the fake implementation for the custom op contained an incorrect output dimension calculation, and a misleading error message in the kernel's support check was flagged for improvement.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Signed-off-by: Han Lin <hanlin12@amd.com>

Signed-off-by: hanlin12 <hanlin12@amd.com>

hanlin12-AMD · 2026-05-13T15:13:07Z

@hanlin12-AMD Can you perform the following test plan? Thanks.

Pick a model that uses the kernels

Run with enabling the kernel, and get the lm_eval score.

Run with disabling the kernel, and get the lm_eval score.

Show a snippet of the message we will see to know that aiter is doing online tuning.

@tjtanaa The comparison table of Qwen3-32B is listed below.

vllmellm · 2026-05-14T02:10:09Z

@tjtanaa The comparison table is listed below.

@hanlin12-AMD which model did you use for this test?

hanlin12-AMD · 2026-05-15T01:51:13Z

@tjtanaa The comparison table is listed below.

@hanlin12-AMD which model did you use for this test?

It is Qwen3-32B. I just added the model name in the previous comment.

Signed-off-by: hanlin12 <hanlin12@amd.com>

tjtanaa · 2026-05-26T13:02:12Z

@hanlin12-AMD I didn't see any logs saying that hipblaslt is performing online tuning?

tjtanaa

LGTM

mergify · 2026-05-27T16:10:14Z

Hi @hanlin12-AMD, the pre-commit checks have failed. Please run:

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mergify · 2026-05-28T04:39:48Z

Hi @hanlin12-AMD, the pre-commit checks have failed. Please run:

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AndreasKaratzas · 2026-05-28T05:09:48Z

    VLLM_ROCM_USE_AITER: bool = False
    VLLM_ROCM_USE_AITER_PAGED_ATTN: bool = False
    VLLM_ROCM_USE_AITER_LINEAR: bool = True
+    VLLM_ROCM_USE_AITER_LINEAR_HIPBMM: bool = False


Please add example documentation of where this env var can prove useful. Use cases of models or set ups that exhibit perf boost or some kind of advantage. People are not going to know how to use this env var.

Currently we don't have a page on vLLM documentation page that we logged down all of the aiter flags. (Let me code them up this week).
This new kernel will be kept as experimental for now as it is not enabled by default. However, it does have one good benefit over AITER's CK PTPC kernel is that this kernel can be tuned on the fly with vllm serve. The AITER CK kernels are extremely not friendly as we need to perform offline tuning and make sure to upstream to aiter before we can consume in vLLM.

Signed-off-by: hanlin12 <hanlin12@amd.com>

mergify · 2026-05-29T02:56:09Z

Hi @hanlin12-AMD, the pre-commit checks have failed. Please run:

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pre-commit install
pre-commit run --all-files

Then, commit the changes and push to your branch.

For future commits, pre-commit will run automatically on changed files before each commit.

Tip

Is mypy failing?

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# For mypy (substitute "3.10" with the failing version if needed)
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Signed-off-by: hanlin12 <hanlin12@amd.com>

AndreasKaratzas

LGTM

…ect#40426) Signed-off-by: hanlin12 <hanlin12@amd.com> Signed-off-by: Han Lin <hanlin12@amd.com> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Co-authored-by: TJian <tunjian.tan@embeddedllm.com> Signed-off-by: JisoLya <523420504@qq.com>

Resolves the recurring envs.py merge conflict per docs/superpowers/specs/2026-05-14-envs-merge-conflict-resolution-design.md. The legacy `if TYPE_CHECKING:` block and `environment_variables: dict[str, Callable]` runtime mapping were dropped on the branch in favor of pydantic `*Settings(BaseSettings)` subclasses. Every main-side edit to either location therefore conflicts mechanically; structural resolution is `--ours` for vllm/envs.py, then port the semantic delta as new `Field(...)` declarations on the appropriate sub-model. Main-side commits since merge base afcb580, with port disposition: - c73b0d0 (vllm-project#44669) — adds VLLM_RAY_DP_PLACEMENT_NODE_IPS (str=""). Ported to DistributedSettings.ray_dp_placement_node_ips. - 165b786 (vllm-project#40426) — adds VLLM_ROCM_USE_AITER_LINEAR_HIPBMM (bool=False). Ported to RocmSettings.rocm_use_aiter_linear_hipbmm. Native pydantic bool parsing replaces the `.lower() in ("true","1")` lambda. - 38fd240 (vllm-project#41980) — adds VLLM_DISTRIBUTED_USE_SPLIT_GROUP (bool=False). Ported to DistributedSettings.distributed_use_split_group. Native pydantic bool parsing replaces the `bool(int(...))` lambda. - a618356 (vllm-project#43447) — adds VLLM_PREFIX_CACHE_RETENTION_INTERVAL (int|None=None, tri-state). Ported to ServerSettings.prefix_cache_retention_interval; pydantic's unset-vs-explicit-zero handling matches the original `"X" in os.environ` guard. - bd98e97 (vllm-project#44128) — removes dead VLLM_RPC_TIMEOUT. Mirrored on the branch by deleting ServerSettings.rpc_timeout. Verification: vllm.envs imports cleanly; all four new vars read defaults and parse env-set values (incl. tri-state INTERVAL=0); VLLM_RPC_TIMEOUT correctly raises AttributeError; pre-commit passes ruff/format/mypy. Signed-off-by: Vinay Damodaran <vrdn@hey.com>

…ect#40426) Signed-off-by: hanlin12 <hanlin12@amd.com> Signed-off-by: Han Lin <hanlin12@amd.com> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Co-authored-by: TJian <tunjian.tan@embeddedllm.com>

…ect#40426) Signed-off-by: hanlin12 <hanlin12@amd.com> Signed-off-by: Han Lin <hanlin12@amd.com> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Co-authored-by: TJian <tunjian.tan@embeddedllm.com> Signed-off-by: Ekagra Ranjan <3116519+ekagra-ranjan@users.noreply.github.com>

…ect#40426) Signed-off-by: hanlin12 <hanlin12@amd.com> Signed-off-by: Han Lin <hanlin12@amd.com> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Co-authored-by: TJian <tunjian.tan@embeddedllm.com> Signed-off-by: Waqar Ahmed <waqar.ahmed@amd.com>

hanlin12-AMD added 16 commits March 16, 2026 08:17

Add the option to turn on hipBLASLt online tuning

a864404

Signed-off-by: hanlin12 <hanlin12@amd.com>

move hip_online_tuning option into serve.py

96cf2d1

Signed-off-by: hanlin12 <hanlin12@amd.com>

use environment variable instead of CLI

d5753b3

Signed-off-by: hanlin12 <hanlin12@amd.com>

Merge branch 'main' into hip_online_tuning

8136fe7

Signed-off-by: Han Lin <hanlin12@amd.com>

fixup suffix of environment variable

7abf916

Signed-off-by: hanlin12 <hanlin12@amd.com>

Merge branch 'main' into hip_online_tuning

9c8fd55

Merge branch 'main' into hip_online_tuning

838438d

Merge branch 'main' into hip_online_tuning

f6c46d1

Merge branch 'vllm-project:main' into hip_online_tuning

6443ef9

add unit test for AITER hipBLASLt online tuning

47744cf

fix typos in comment

eccbced

Merge branch 'vllm-project:main' into hip_online_tuning

2e0a6a5

Merge branch 'vllm-project:main' into hip_online_tuning

f08dd93

Add AITER hipBLASLt GEMM kernel in vLLM

f33bfe5

Signed-off-by: hanlin12 <hanlin12@amd.com>

Merge branch 'vllm-project:main' into hip_online_tuning

879ccbe

Merge branch 'main' into hip_online_tuning

7b56a01

hanlin12-AMD requested a review from tjtanaa as a code owner April 21, 2026 03:07

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Update vllm/model_executor/kernels/linear/scaled_mm/aiter.py

ea9cef5

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Signed-off-by: Han Lin <hanlin12@amd.com>

mergify Bot added the rocm Related to AMD ROCm label Apr 21, 2026

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hanlin12-AMD and others added 2 commits April 21, 2026 15:40

Update vllm/_aiter_ops.py

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Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Signed-off-by: Han Lin <hanlin12@amd.com>

Remove the contiguous() after preshuffle

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Signed-off-by: hanlin12 <hanlin12@amd.com>

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Comment thread vllm/model_executor/kernels/linear/scaled_mm/aiter.py Outdated

fix some variable name

d001385

Signed-off-by: hanlin12 <hanlin12@amd.com>

fix missing line in aiter_ops

bdb9d33

Signed-off-by: hanlin12 <hanlin12@amd.com>

tjtanaa reviewed May 26, 2026

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Comment thread vllm/_aiter_ops.py

hanlin12-AMD requested a review from dllehr-amd as a code owner May 26, 2026 14:24

tjtanaa approved these changes May 27, 2026

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tjtanaa added the ready ONLY add when PR is ready to merge/full CI is needed label May 27, 2026

Merge branch 'main' into aiter_hipbmm_online_tuning

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Merge branch 'main' into aiter_hipbmm_online_tuning

30599ba

tjtanaa requested a review from AndreasKaratzas as a code owner May 28, 2026 04:34

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hanlin12-AMD added 2 commits May 28, 2026 09:11

fix pre-commit

6b52d97

Signed-off-by: hanlin12 <hanlin12@amd.com>

Add accuracy unit-test of Aiter hipBlaslt

6c0d85e

Signed-off-by: hanlin12 <hanlin12@amd.com>

hanlin12-AMD and others added 2 commits May 29, 2026 03:05

fix pre-commit

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Signed-off-by: hanlin12 <hanlin12@amd.com>

Merge branch 'main' into aiter_hipbmm_online_tuning

df814ac

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vllm-bot merged commit 165b786 into vllm-project:main Jun 5, 2026
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