First round of patches for linux-4.7 Add a generic facility for sockets to be freed after an RCU grace period, if they need to.
Then UDP stack is changed to no longer use SLAB_DESTROY_BY_RCU, in order to speedup rx processing for traffic encapsulated in UDP. It gives a 17 % speedup for normal UDP reception in stress conditions. Then TCP listeners are changed to use SOCK_RCU_FREE as well to avoid touching sk_refcnt in synflood case : I got up to 30 % performance increase for a mono listener. Then three patches add SK_MEMINFO_DROPS to sock_diag and add per socket rx drops accounting to TCP. Last patch adds rate limiting on ACK sent on behalf of SYN_RECV to better resist to SYNFLOOD targeting one or few flows. Eric Dumazet (11): net: add SOCK_RCU_FREE socket flag udp: no longer use SLAB_DESTROY_BY_RCU tcp/dccp: remove BH disable/enable in lookup tcp/dccp: use rcu locking in inet_diag_find_one_icsk() inet: reqsk_alloc() needs to take care of dead listeners tcp/dccp: do not touch listener sk_refcnt under synflood sock_diag: add SK_MEMINFO_DROPS tcp: increment sk_drops for dropped rx packets tcp: increment sk_drops for listeners ipv4: tcp: set SOCK_USE_WRITE_QUEUE for ip_send_unicast_reply() tcp: rate limit ACK sent by SYN_RECV request sockets include/linux/udp.h | 8 +- include/net/inet6_hashtables.h | 12 +- include/net/inet_hashtables.h | 47 +++---- include/net/request_sock.h | 31 +++-- include/net/sock.h | 21 ++- include/net/tcp.h | 13 ++ include/net/udp.h | 2 +- include/uapi/linux/sock_diag.h | 1 + net/core/sock.c | 15 ++- net/core/sock_diag.c | 1 + net/dccp/ipv4.c | 7 +- net/dccp/ipv6.c | 7 +- net/ipv4/inet_diag.c | 10 +- net/ipv4/inet_hashtables.c | 77 ++++------- net/ipv4/tcp_input.c | 41 +++--- net/ipv4/tcp_ipv4.c | 74 ++++++----- net/ipv4/tcp_minisocks.c | 5 +- net/ipv4/udp.c | 293 ++++++++++++----------------------------- net/ipv4/udp_diag.c | 18 +-- net/ipv6/inet6_hashtables.c | 62 +++------ net/ipv6/tcp_ipv6.c | 32 +++-- net/ipv6/udp.c | 196 +++++++++------------------ net/netfilter/xt_socket.c | 6 +- 23 files changed, 401 insertions(+), 578 deletions(-) -- 2.8.0.rc3.226.g39d4020
