tools/build/feature/test-eventfd.c (5 lines of code) (raw):

// SPDX-License-Identifier: GPL-2.0 // Copyright (C) 2018, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com> #include <sys/eventfd.h> int main(void) { return eventfd(0, EFD_NONBLOCK); }