Comment 6 for bug 478691

It's not that simple -- we need to actively discriminate against long builds or daily PPAs and prevent them from ever taking up all of the builders. Imagine a situation (that happens daily) where there are enough two-hour daily builds from various PPAs to fill all of the builders. Queuing other builds ahead of those will work for a while, but as soon as the non-daily queue empties the dailies will take over every builder. Once that happens, nothing else can build for a couple of hours.