Commits
Eric Dumazet committed 55a93b3ea78
qdisc: validate skb without holding lock Validation of skb can be pretty expensive : GSO segmentation and/or checksum computations. We can do this without holding qdisc lock, so that other cpus can queue additional packets. Trick is that requeued packets were already validated, so we carry a boolean so that sch_direct_xmit() can validate a fresh skb list, or directly use an old one. Tested on 40Gb NIC (8 TX queues) and 200 concurrent flows, 48 threads host. Turning TSO on or off had no effect on throughput, only few more cpu cycles. Lock contention on qdisc lock disappeared. Same if disabling TX checksum offload. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>