tcp/dccp: lockless listener

tcp/dccp: lockless listener

From:		Eric Dumazet
To:		"David S . Miller"
Subject:		[PATCH net-next 00/17] tcp/dccp: lockless listener
Date:		Fri, 2 Oct 2015 11:43:22 -0700
Message-ID:		<[email protected]>
Cc:		netdev , Eric Dumazet , Ying Cai , Willem de Bruijn , Eric Dumazet
Archive-link:		Article, Thread

TCP listener refactoring : this is becoming interesting !

This patch series takes the steps to use normal TCP/DCCP ehash
table to store SYN_RECV requests, instead of the private per-listener
hash table we had until now.

SYNACK skb are now attached to their syn_recv request socket,
so that we no longer heavily modify listener sk_wmem_alloc.

listener lock is no longer held in fast path, including
SYNCOOKIE mode.

During my tests, my server was able to process 3,500,000
SYN packets per second on one listener and still had available
cpu cycles.

That is about 2 to 3 order of magnitude what we had with older kernels.

This effort started two years ago and I am pleased to reach expectations.

We'll probably extend SO_REUSEPORT toC   9 --
 include/net/inet_connection_sock.h  |   9 +-
 include/net/inetiloing thanks to multi-queues
NIC.

Eric Dumazet (17):
  tcp: add a spinlock to protect struct request_sock_queue
  tcp: move qlen/young out of struct listen_sock
  tcp: move synflood_warned into struct request_sock_queue
  tcp: call sk_mark_napi_id() on the child, not the listener
  tcp/dccp: init sk_prot and call sk_node_init() in reqsk_alloc()
  tcp: cleanup tcp_v[46]_inbound_md5_hash()
 %2                    |  72 +++++-----------
 net/ipv4/inet_connection_sock.c     | 145 ++++++++------------------------
 net/ipv4/inet_diag.c                |  96 ++--------------------
 net/ipv4/inet_hashtables.c          |  14 +++-
 net/ipv4/syncookies.c               |   4 +
 net/ipv4/tcp_fastopen.c             |   4 +-
 net/ipv4/tcp_input.c                |  30 +++----
 net/ipv4/tcp_ipv4.c                 | 159 +++++++++++++-----------------------
 net%_hashtables.h       |   1 +
 include/net/request_sock.h          | 132 ++++++++++--------------------
 include/net/tcp.h                   |  10 +--
 net/core/request_sock.c             |  84 +------------------
 net/dccp/ipv4.c                     |  64 +++++----------
 net/dccp/ipv6.c                     |  72 +++++-----------
 net/ipv4/inet_connection_sock.c     | 145 ++++++++------------------------
 net/ipv4/inet_diag.c                |  96 ++--------------------
 net/ipv4/inet_hashtables.c          |  14 +++-
 net/ipv4/syncookies.c               |   4 +
 net/ipv4/tcp_fastopen.c             |   4 +-
 net/ipv4/tcp_input.c                |  30 +++----
 net/ipv4/tcp_ipv4.c                 | 159 +++++++++++++-----------------------
 net/ipv4/tcp_minisocks.c            |   2 -
 net/ipv4/tcp_output.c               |  22 +++--
 net/ipv6/inet6_connection_sock.c    |  67 ---------------
 net/ipv6/tcp_ipv6.c                 | 117 +++++++++++++-------------
 net/sched/sch_fq.c                  |  12 +--
 20 files changed, 307 insertions(+), 746 deletions(-)

-- 
2.6.0.rc2.230.g3dd15c0