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[MoE Refactor] Create MK for TRTLLM Kernels (#32564)

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Signed-off-by: Robert Shaw <robshaw@redhat.com>
Signed-off-by: Robert Shaw <rshaw@neuralmagic.com>
Signed-off-by: Robert Shaw <robertgshaw2@gmail.com>
Co-authored-by: Robert Shaw <robshaw@redhat.com>
Co-authored-by: Robert Shaw <rshaw@neuralmagic.com>
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Robert Shaw
2026-03-03 13:39:50 -05:00
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parent 881a6b011b
commit 97995f6376
77 changed files with 2575 additions and 2087 deletions
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docs/design/moe_kernel_features.md
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@@ -4,17 +4,17 @@ The purpose of this document is to provide an overview of the various MoE kernel
## Fused MoE Modular All2All backends
There are a number of all2all communication backends that are used to implement expert parallelism (EP) for the `FusedMoE` layer. The different `FusedMoEPrepareAndFinalize` subclasses provide an interface for each all2all backend.
There are a number of all2all communication backends that are used to implement expert parallelism (EP) for the `FusedMoE` layer. The different `FusedMoEPrepareAndFinalizeModular` subclasses provide an interface for each all2all backend.
The following table describes the relevant features of each backend, i.e. activation format, supported quantization schemes and async support.
The output activation format (standard or batched) corresponds to the output of the prepare step of the `FusedMoEPrepareAndFinalize` subclass, and the finalize step requires the same format. All the backend `prepare` methods expect activations in the standard format and all the `finalize` methods return activations in standard format. More details on the formats can be found in the [Fused MoE Modular Kernel](./fused_moe_modular_kernel.md) document.
The output activation format (standard or batched) corresponds to the output of the prepare step of the `FusedMoEPrepareAndFinalizeModular` subclass, and the finalize step requires the same format. All the backend `prepare` methods expect activations in the standard format and all the `finalize` methods return activations in standard format. More details on the formats can be found in the [Fused MoE Modular Kernel](./fused_moe_modular_kernel.md) document.
The quantization types and formats enumerate which quantization schemes are supported by each `FusedMoEPrepareAndFinalize` class. The quantization can happen before or after the dispatch based on the format the all2all backend supports, e.g. deepep_high_throughput supports only block-quantized fp8 format. Any other format will result in dispatching in higher precision and quantizing afterwards. The output of the prepare step for each backend is the quantized type. The finalize step generally requires the same input type as the original activations, e.g. if the original input is bfloat16 and the quantization scheme is fp8 with per-tensor scales, `prepare` will return fp8/per-tensor scale activations and `finalize` will take bfloat16 activations. See the diagrams in [Fused MoE Modular Kernel](./fused_moe_modular_kernel.md) for more details on the types and formats of activations at each step of the MoE process. If no quantization type is specified, the kernel operates on float16 and/or bfloat16.
The quantization types and formats enumerate which quantization schemes are supported by each `FusedMoEPrepareAndFinalizeModular` class. The quantization can happen before or after the dispatch based on the format the all2all backend supports, e.g. deepep_high_throughput supports only block-quantized fp8 format. Any other format will result in dispatching in higher precision and quantizing afterwards. The output of the prepare step for each backend is the quantized type. The finalize step generally requires the same input type as the original activations, e.g. if the original input is bfloat16 and the quantization scheme is fp8 with per-tensor scales, `prepare` will return fp8/per-tensor scale activations and `finalize` will take bfloat16 activations. See the diagrams in [Fused MoE Modular Kernel](./fused_moe_modular_kernel.md) for more details on the types and formats of activations at each step of the MoE process. If no quantization type is specified, the kernel operates on float16 and/or bfloat16.
Async backends support the use of DBO (Dual Batch Overlap) and shared expert overlap (where shared experts are computed during the combine step).
Certain models require the topk weights to be applied to the input activations rather than the output activations when topk==1, e.g. Llama. For modular kernels, this feature is supported by the `FusedMoEPrepareAndFinalize` subclass. For non-modular kernels, it is up to the experts function to deal with this flag.
Certain models require the topk weights to be applied to the input activations rather than the output activations when topk==1, e.g. Llama. For modular kernels, this feature is supported by the `FusedMoEPrepareAndFinalizeModular` subclass. For non-modular kernels, it is up to the experts function to deal with this flag.
Unless otherwise specified, backends are controlled via the `--all2all-backend` command-line argument (or the `all2all_backend` parameter in `ParallelConfig`). All backends except `flashinfer` only work with EP+DP or EP+TP. `Flashinfer` can work with EP or DP without EP.
@@ -36,8 +36,6 @@ th {
| deepep_high_throughput | standard | fp8 | G(128),A,T<sup>2</sup> | Y | Y | [`DeepEPHTPrepareAndFinalize`][vllm.model_executor.layers.fused_moe.deepep_ht_prepare_finalize.DeepEPHTPrepareAndFinalize] |
| deepep_low_latency | batched | fp8 | G(128),A,T<sup>3</sup> | Y | Y | [`DeepEPLLPrepareAndFinalize`][vllm.model_executor.layers.fused_moe.deepep_ll_prepare_finalize.DeepEPLLPrepareAndFinalize] |
| flashinfer_all2allv | standard | nvfp4,fp8 | G,A,T | N | N | [`FlashInferA2APrepareAndFinalize`][vllm.model_executor.layers.fused_moe.flashinfer_a2a_prepare_finalize.FlashInferA2APrepareAndFinalize] |
| MoEPrepareAndFinalizeNoEP<sup>5</sup> | standard | fp8,int8 | G,A,T | N | Y | [`MoEPrepareAndFinalizeNoEP`][vllm.model_executor.layers.fused_moe.prepare_finalize.MoEPrepareAndFinalizeNoEP] |
| BatchedPrepareAndFinalize<sup>5</sup> | batched | fp8,int8 | G,A,T | N | Y | [`BatchedPrepareAndFinalize`][vllm.model_executor.layers.fused_moe.fused_batched_moe.BatchedPrepareAndFinalize] |
!!! info "Table key"
1. All types: mxfp4, nvfp4, int4, int8, fp8
@@ -75,9 +73,9 @@ Each experts kernel supports one or more activation functions, e.g. silu or gelu
As with the backends, some experts support applying topk weights on the input activations. The entries in the column in this table only apply to the non-modular experts.
Most experts flavors include an equivalent modular interface which will be a subclass of `FusedMoEPermuteExpertsUnpermute`.
Most experts flavors include an equivalent modular interface which will be a subclass of `FusedMoEExpertsModular`.
To be used with a particular `FusedMoEPrepareAndFinalize` subclass, MoE kernels must have compatible activation formats, quantization types and quantization formats.
To be used with a particular `FusedMoEPrepareAndFinalizeModular` subclass, MoE kernels must have compatible activation formats, quantization types and quantization formats.
| Kernel | Input act. format | Quant. types | Quant. format | Activation function | Apply Weight On Input | Modular | Source |
|--------|-------------------|--------------|---------------|---------------------|-----------------------|---------|--------|
@@ -106,7 +104,7 @@ To be used with a particular `FusedMoEPrepareAndFinalize` subclass, MoE kernels
The following table shows "families" of modular kernels that are intended to work together. There are some combinations which may work but have not yet been tested, e.g. flashinfer with other fp8 experts. Note that the "naive" backend will work with any non-modular experts.
| backend | `FusedMoEPrepareAndFinalize` subclasses | `FusedMoEPermuteExpertsUnpermute` subclasses |
| backend | `FusedMoEPrepareAndFinalizeModular` subclasses | `FusedMoEExpertsModular` subclasses |
|---------|-----------------------------------------|----------------------------------------------|
| deepep_high_throughput | `DeepEPHTPrepareAndFinalize` | `DeepGemmExperts`,</br>`TritonExperts`,</br>`TritonOrDeepGemmExperts`,</br>`CutlassExpertsFp8`, </br>`MarlinExperts` |
| deepep_low_latency | `DeepEPLLPrepareAndFinalize` | `BatchedDeepGemmExperts`,</br>`BatchedTritonExperts`,</br>`CutlassBatchedExpertsFp8`,</br>`BatchedMarlinExperts` |