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vllm-project#42880 gated the ROCm GDN decode fast path on gqa_interleaved_layout because the AITER fused reshape+conv kernel only understood Qwen3-Next's packing and read the wrong columns from a flat [q|k|v|z] tensor. ROCm/aiter#3251 added a qkvz_layout parameter handling both, so we can pass also this layout through and drop the previous guard. Flat layouts keep it on AITER builds without that parameter, detected by probing the kernel signature, since passing it there would raise TypeError. The fast path returns before the whole generic block, so four kernel launches per GDN layer per step become two: the core_attn_out fill and the z_out copy kernels disappear because the AITER kernel writes both buffers itself. Add the gdn directory to the Kernels Mamba source_file_dependencies. Signed-off-by: Mikko Tukiainen <Mikko.Tukiainen@amd.com> Co-authored-by: Cursor <cursoragent@cursor.com>
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Adding E2E perf test to this would be beneficial |
Perf and accuracy A/B test results added in the description. |
The pinned AITER build already carries the qkvz_layout parameter, so the probe was always true and only added a signature inspection plus a dead fallback branch. Pass qkvz_layout to the fused reshape+conv kernel directly and drop the tests that covered the probe. Co-authored-by: Cursor <cursoragent@cursor.com> Signed-off-by: Mikko Tukiainen <Mikko.Tukiainen@amd.com>
| source_file_dependencies: | ||
| - csrc/mamba/ | ||
| - tests/kernels/mamba | ||
| - vllm/model_executor/layers/mamba/gdn |
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@AndreasKaratzas Are we okay if we add this testgroup to cover the gdn change?
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Yep, I think it's fine, it's not adding really a test group, it's instructing the execution of an existing test group if future PRs touch the added path, so I'm good with that
…t-path-flat-layout
AndreasKaratzas
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✅ @mjkvaak-amd, CI is now available for this PR.
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❌ This PR is 23 commits behind upstream |
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✅ Triggered Buildkite CI #89373 for commit
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✅ Triggered Buildkite CI #89837 for commit |
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✅ Queued 5 failed job(s) for retry in Buildkite CI #89837. |
| QwenGatedDeltaNetAttention, | ||
| ) | ||
| from vllm.v1.attention.backends.gdn_attn import GDNAttentionMetadata | ||
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@mjkvaak-amd since this is a rocm exclusive test, please guard it with pyskip so that we skip the test if it is not on rocm
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Thanks! Now gated behind current_platform.is_rocm()
The dispatch tests cover _forward_core_rocm, so skip them off HIP as requested in review. Signed-off-by: Mikko Tukiainen <Mikko.Tukiainen@amd.com>
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✅ Triggered Buildkite CI #89880 for commit |
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✅ Queued 8 failed job(s) for retry in Buildkite CI #89880. |
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✅ Queued 1 failed job(s) for retry in Buildkite CI #89880. |
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✅ Triggered Buildkite CI #89956 for commit |
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✅ Queued 5 failed job(s) for retry in Buildkite CI #89956. |
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✅ Triggered Buildkite CI #89975 for commit |
6 participants
Purpose
_forward_core_rocmcurrently gates the AITER GDN decode fast path onself.gqa_interleaved_layout, so only Qwen3-Next takes it and flat-layout models (e.g. Qwen3.5, Qwen3.8) fall through to the generic path. #42880 added that guard because the fused reshape+conv kernel only understood Qwen3-Next's packing and read the wrong columns from a flat tensor.ROCm/aiter#3251 added a
qkvz_layoutparameter handling both. It selects the source index mapping only — outputs stay in canonical order, so the downstreamfused_rearrange_sigmoid_gated_delta_ruleis unchanged — and"interleaved"stays the default, so Qwen3-Next is bit-identical. This PR passes the layout through and drops the layout guard. Older AITER builds would raiseTypeError, sogdn_fused_conv_supports_qkvz_layout()probes the signature once (mirroringfused_moe_supports_gate_mode()) and flat layouts keep the guard there.The fast path returns before the entire generic block, so four kernel launches per GDN layer per step become two:
core_attn_out.zero_()andz_out[:] = zare pure removals, since the AITER kernel writes both buffers including the padding rows abovenum_actual_tokens.Also adds
vllm/model_executor/layers/mamba/gdnto the Kernels Mambasource_file_dependencies, which did not list it.Test Plan
New host-side tests (CPU, no GPU or AITER needed) covering flat dispatch with and without kernel support, Qwen3-Next non-regression on both, batch shapes that must stay generic, and the capability probe. Accuracy uses the
lm_evalinvocation from #42880; performance uses decode traces ofamd/Qwen3.8-2.4T-A95B-Quark-MXFP4on 8x MI355X.Test Result
Performance: Serving benchmark on
amd/Qwen3.8-2.4T-A95B-Quark-MXFP4, 8x MI355X, TP8, fixed input/output lengths (--random-range-ratio 0), one run per point, measured against a stock build of the same commit.Accuracy: GSM8K, 5-shot, seed 4321,
batch_size=128:No accuracy regression.
(Decode) trace:
core_attn_out.zero_()direct_copy_kernel(z_out[:] = z)_causal_conv1d_update_kernelfused_recurrent_gated_delta_rule_packed_decode_kernel_reshape_causal_conv1d_update_single_token_kernelfused_rearrange_sigmoid_gated_delta_rule_update_kernelCurrent main:
This PR:
Essential Elements of an Effective PR Description Checklist
supported_models.mdandexamplesfor a new model.Co-authored-by: Cursor