Commits
Eric Dumazet committed 6b229cf77d6
udp: add batching to udp_rmem_release() If udp_recvmsg() constantly releases sk_rmem_alloc for every read packet, it gives opportunity for producers to immediately grab spinlocks and desperatly try adding another packet, causing false sharing. We can add a simple heuristic to give the signal by batches of ~25 % of the queue capacity. This patch considerably increases performance under flood by about 50 %, since the thread draining the queue is no longer slowed by false sharing. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>