---
id: pr-cccl-cub-8522
repo: NVIDIA/cccl
pr: 8522
title: '[CUB] Delegate large segments to Multi-CTA Implementation in `DeviceSegmentedTopK`'
author: pauleonix
date: '2026-05-06'
url: https://github.com/NVIDIA/cccl/pull/8522
source_category: upstream-code
architectures:
- sm100
tags:
- block
- scan
- warp
techniques:
- warp-specialization
hardware_features: []
kernel_types:
- scan
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 3a1601d8a76d421678ccd4f94774b666ef8f4e29
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cub/cub/agent/agent_batched_topk.cuh
- cub/cub/device/dispatch/dispatch_batched_topk.cuh
- cub/cub/device/dispatch/kernels/kernel_batched_topk.cuh
- cub/cub/device/dispatch/tuning/tuning_batched_topk.cuh
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8522
head_ref_oid: 60f18b383f8980e68450fcbcdcecd69ba8b676e6
---
# [CUB] Delegate large segments to Multi-CTA Implementation in `DeviceSegmentedTopK`

- Repository: `NVIDIA/cccl`
- PR: [8522](https://github.com/NVIDIA/cccl/pull/8522)
- 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/agent/agent_batched_topk.cuh`
- `cub/cub/device/dispatch/dispatch_batched_topk.cuh`
- `cub/cub/device/dispatch/kernels/kernel_batched_topk.cuh`
- `cub/cub/device/dispatch/tuning/tuning_batched_topk.cuh`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8522`
