Enable opcache.preload:


php \
    -dopcache.enable=1 -dopcache.enable_cli=1 *-d opcache.preload=preload.inc* \
    -d ffi.enable=1 \
    -S 0.0.0.0:8080


Stats:


var_dump(opcache_get_status()['preload_statistics']);


Once loaded, only a restart of the web server (or PHP-FPM) will reload files