Man pages matching name futex in section 2:

futex.2.en	debian 10 / manpages-dev
futex.2.es	debian 10 / manpages-es
futex.2.ja	debian 10 / manpages-ja-dev
futex.2.en	debian 11 / manpages-dev
futex.2.fr	debian 11 / manpages-fr-dev
futex.2.ja	debian 11 / manpages-ja-dev
futex.2.en	debian 12 / manpages-dev
futex.2.fr	debian 12 / manpages-fr-dev
futex.2.ja	debian 12 / manpages-ja-dev
futex.2.ru	debian 12 / manpages-ru-dev