reproduce:
        git checkout 6b8edfcd661b569f077cc1ea1f7463ec38547779
        b4 shazam https://lore.kernel.org/r/20260130-ksm_stat-v1-1-a6aa0da78de6@wiredspace.de
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs