$options['cpuLimit'] + 1, # hard limit

if ( php_uname( 's' ) == 'Linux' ) {
    // Limit memory and CPU
    $cmd = wfEscapeShellArg(
        'exec', # proc_open() passes $cmd to 'sh -c' on Linux, so add an 'exec' to bypass it
        '/bin/sh',
        __DIR__ . '/lua_ulimit.sh',
        $options['cpuLimit'], # soft limit (SIGXCPU)
        $options['cpuLimit'] + 1, # hard limit
        intval( $options['memoryLimit'] / 1024 ),
        $cmd );
}