---
id: pr-cccl-cub-8657
repo: NVIDIA/cccl
pr: 8657
title: Add a killswitch for warpspeed scan
author: bernhardmgruber
date: '2026-04-24'
url: https://github.com/NVIDIA/cccl/pull/8657
source_category: upstream-code
architectures:
- sm100
tags:
- scan
techniques:
- warp-specialization
hardware_features: []
kernel_types:
- scan
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 52f34203dd98d421bc79f6065e537e802ce9f823
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cub/cub/device/dispatch/tuning/tuning_scan.cuh
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8657
head_ref_oid: 68ffab42294ec21255c7678805f5f17da0385843
---
# Add a killswitch for warpspeed scan

- Repository: `NVIDIA/cccl`
- PR: [8657](https://github.com/NVIDIA/cccl/pull/8657)
- Decision: `Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.`
- Reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.

## Changed Paths

- `cub/cub/device/dispatch/tuning/tuning_scan.cuh`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8657`
