---
id: pr-vllm-15492
repo: vllm-project/vllm
pr: 15492
title: '[BugFix] Fix nightly MLA failure (FA2 + MLA chunked prefill, i.e. V1, producing bad results)'
author: LucasWilkinson
date: '2025-03-26'
url: https://github.com/vllm-project/vllm/pull/15492
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- mla
- prefill
techniques: []
hardware_features: []
kernel_types:
- attention
- mla
- prefill
languages:
- triton
captured_at: '2026-04-27'
status: merged
merge_sha: 33437bc6e7af316fa9ce6b6e559501ca45d9cd45
inclusion_reason: kernel file changes
changed_paths:
- vllm/attention/ops/triton_merge_attn_states.py
head_ref_oid: 5e1d5418503e9826a466a685b4dfd4c7fcf63f46
artifact_dir: evidence/pull-bundles/vllm/gh-15492
---
# [BugFix] Fix nightly MLA failure (FA2 + MLA chunked prefill, i.e. V1, producing bad results)

- Repository: `vllm-project/vllm`
- PR: [15492](https://github.com/vllm-project/vllm/pull/15492)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `vllm/attention/ops/triton_merge_attn_states.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-15492`
