Merge branch 'net-sched-singly-linked-list'
Florian Westphal says: ==================== sched: convert queues to single-linked list During Netfilter Workshop 2016 Eric Dumazet pointed out that qdisc schedulers use doubly-linked lists, even though single-linked list would be enough. The double-linked skb lists incur one extra write on enqueue/dequeue operations (to change ->prev pointer of next list elem). This series converts qdiscs to single-linked version, listhead maintains pointers to first (for dequeue) and last skb (for enqueue). Most qdiscs don't queue at all and instead use a leaf qdisc (typically pfifo_fast) so only a few schedulers needed changes. I briefly tested netem and htb and they seemed fine. UDP_STREAM netperf with 64 byte packets via veth+pfifo_fast shows a small (~2%) improvement. ==================== Signed-off-by: David S. Miller <email@example.com>