Comment 12 for bug 1626651

On the u-s-d side there is some potential optimization: Ideally the brightness would always be set through xrandr XBACKLIGHT, which works unprivileged, and only fall back to the helper if that is not available and the brightness needs to be set via sysfs properties. However, even then there is no reason why --get-brightness would need particular privileges: these sysfs attributes are world-readable, and only --set-brightness (writing the attribute) needs root. This would already cut away half of the overhead.