My personal style here is to use a number of goroutines equal to the desired concurrency. I know goroutines are cheap and there is no particular reason to conserve them most of the time, but this feels more natural to me than using a semaphore--although it is less flexible.

Simplified:

    var wg sync.WaitGroup
    wg.Add(jobs)
    ch := make(chan workItem, jobs)
    for i := 0; i < jobs; i++ {
        go func() {
            defer wg.Done()
            for item := range ch {
                processItem(item)
            }
        }()
    }
    for _, item := range items {
        ch <- item
    }
    close(ch)
    wg.Wait()