---
id: pr-vllm-40950
repo: vllm-project/vllm
pr: 40950
title: '[DSV4] Add silu clamp limit to shared expert'
author: zyongye
date: '2026-04-27'
url: https://github.com/vllm-project/vllm/pull/40950
source_category: upstream-code
architectures:
- sm100
tags:
- CUDA kernel
- benchmark_test
- moe_routing
- norm_elementwise
techniques:
- kernel-fusion
hardware_features: []
kernel_types:
- moe
- norm
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 706a04d34ba64ea23d430d5e50038791aacfae96
inclusion_reason: Look for fusion, vectorization, dtype conversion, and store-traffic reductions before changing math.
changed_paths:
- csrc/activation_kernels.cu
- csrc/ops.h
- csrc/torch_bindings.cpp
- tests/kernels/core/test_activation.py
- vllm/model_executor/layers/activation.py
- vllm/model_executor/layers/fused_moe/cpu_fused_moe.py
- vllm/model_executor/models/deepseek_v4.py
artifact_dir: evidence/pull-bundles/vllm/gh-40950
head_ref_oid: 1c6a3afd8e45eec3c7067b1df13a08d6310e372f
---
# [DSV4] Add silu clamp limit to shared expert

- Repository: `vllm-project/vllm`
- PR: [40950](https://github.com/vllm-project/vllm/pull/40950)
- Decision: `Look for fusion, vectorization, dtype conversion, and store-traffic reductions before changing math.`
- Reason: Look for fusion, vectorization, dtype conversion, and store-traffic reductions before changing math.

## Changed Paths

- `csrc/activation_kernels.cu`
- `csrc/ops.h`
- `csrc/torch_bindings.cpp`
- `tests/kernels/core/test_activation.py`
- `vllm/model_executor/layers/activation.py`
- `vllm/model_executor/layers/fused_moe/cpu_fused_moe.py`
- `vllm/model_executor/models/deepseek_v4.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-40950`
