---
id: pr-vllm-42112
repo: vllm-project/vllm
pr: 42112
title: '[Bugfix] Fix TRTLLM ragged MLA prefill workspace warmup'
author: mmangkad
date: '2026-05-14'
url: https://github.com/vllm-project/vllm/pull/42112
source_category: upstream-code
architectures:
- sm100
tags:
- FlashInfer
- attention_kv
techniques: []
hardware_features: []
kernel_types:
- attention
- mla
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 2317682f95114c4088b9223473a8c50836deb994
inclusion_reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.
changed_paths:
- vllm/v1/attention/backends/mla/prefill/flashinfer.py
- vllm/v1/attention/backends/mla/prefill/trtllm_ragged.py
artifact_dir: evidence/pull-bundles/vllm/gh-42112
head_ref_oid: 3967b3517160a7de8c786e067f1e6e1ab0e3324c
---
# [Bugfix] Fix TRTLLM ragged MLA prefill workspace warmup

- Repository: `vllm-project/vllm`
- PR: [42112](https://github.com/vllm-project/vllm/pull/42112)
- Decision: `Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.`
- Reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.

## Changed Paths

- `vllm/v1/attention/backends/mla/prefill/flashinfer.py`
- `vllm/v1/attention/backends/mla/prefill/trtllm_ragged.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-42112`
