---
id: pr-cccl-cub-7822
repo: NVIDIA/cccl
pr: 7822
title: Use `__block_size__` attribute in `cuda::launch`
author: davebayer
date: '2026-02-27'
url: https://github.com/NVIDIA/cccl/pull/7822
source_category: upstream-code
architectures:
- sm100
tags:
- block
techniques: []
hardware_features: []
kernel_types: []
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: dc66d20d886235381b23d11cae6c823bd765f1ce
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- .clang-format
- libcudacxx/include/cuda/__launch/launch.h
- libcudacxx/include/cuda/std/__cccl/cuda_capabilities.h
artifact_dir: evidence/pull-bundles/cccl-cub/gh-7822
head_ref_oid: 4cfda84f359de9889bd4efcded311b6f8d550ed9
---
# Use `__block_size__` attribute in `cuda::launch`

- Repository: `NVIDIA/cccl`
- PR: [7822](https://github.com/NVIDIA/cccl/pull/7822)
- 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

- `.clang-format`
- `libcudacxx/include/cuda/__launch/launch.h`
- `libcudacxx/include/cuda/std/__cccl/cuda_capabilities.h`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-7822`
