pub(crate) fn get_vendor_id_and_brand() -> HashMap<usize, (String, String)> {
    let mut s = String::new();
    if File::open("/proc/cpuinfo")
        .and_then(|mut f| f.read_to_string(&mut s))
        .is_err()
    {
        return HashMap::new();
    }
    get_vendor_id_and_brand_inner(&s)
}
Returns the brand/vendor string for the first CPU (which should be the same for all CPUs).
src/unix/linux/cpu.rs