On Thu, Dec 7, 2017 at 9:58 AM, John Fastabend <john.fastab...@gmail.com> wrote: > This converts the pfifo_fast qdisc to use the skb_array data structure > and set the lockless qdisc bit. pfifo_fast is the first qdisc to support > the lockless bit that can be a child of a qdisc requiring locking. So > we add logic to clear the lock bit on initialization in these cases when > the qdisc graft operation occurs. > > This also removes the logic used to pick the next band to dequeue from > and instead just checks a per priority array for packets from top priority > to lowest. This might need to be a bit more clever but seems to work > for now.
A very dumb question: Why do we call it lockless? With skb_array you just shift the per qdisc spinlock down to each pfifo band, skb_array still uses a spinlock underneath. What am I missing here?