freebsd-nq/sys/netinet6/in6_pcb.h
Robert Watson 52cd27cb58 Implement a CPU-affine TCP and UDP connection lookup data structure,
struct inpcbgroup.  pcbgroups, or "connection groups", supplement the
existing inpcbinfo connection hash table, which when pcbgroups are
enabled, might now be thought of more usefully as a per-protocol
4-tuple reservation table.

Connections are assigned to connection groups base on a hash of their
4-tuple; wildcard sockets require special handling, and are members
of all connection groups.  During a connection lookup, a
per-connection group lock is employed rather than the global pcbinfo
lock.  By aligning connection groups with input path processing,
connection groups take on an effective CPU affinity, especially when
aligned with RSS work placement (see a forthcoming commit for
details).  This eliminates cache line migration associated with
global, protocol-layer data structures in steady state TCP and UDP
processing (with the exception of protocol-layer statistics; further
commit to follow).

Elements of this approach were inspired by Willman, Rixner, and Cox's
2006 USENIX paper, "An Evaluation of Network Stack Parallelization
Strategies in Modern Operating Systems".  However, there are also
significant differences: we maintain the inpcb lock, rather than using
the connection group lock for per-connection state.

Likewise, the focus of this implementation is alignment with NIC
packet distribution strategies such as RSS, rather than pure software
strategies.  Despite that focus, software distribution is supported
through the parallel netisr implementation, and works well in
configurations where the number of hardware threads is greater than
the number of NIC input queues, such as in the RMI XLR threaded MIPS
architecture.

Another important difference is the continued maintenance of existing
hash tables as "reservation tables" -- these are useful both to
distinguish the resource allocation aspect of protocol name management
and the more common-case lookup aspect.  In configurations where
connection tables are aligned with hardware hashes, it is desirable to
use the traditional lookup tables for loopback or encapsulated traffic
rather than take the expense of hardware hashes that are hard to
implement efficiently in software (such as RSS Toeplitz).

Connection group support is enabled by compiling "options PCBGROUP"
into your kernel configuration; for the time being, this is an
experimental feature, and hence is not enabled by default.

Subject to the limited MFCability of change dependencies in inpcb,
and its change to the inpcbinfo init function signature, this change
in principle could be merged to FreeBSD 8.x.

Reviewed by:    bz
Sponsored by:   Juniper Networks, Inc.
2011-06-06 12:55:02 +00:00

125 lines
5.8 KiB
C

/*-
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $KAME: in6_pcb.h,v 1.13 2001/02/06 09:16:53 itojun Exp $
*/
/*-
* Copyright (c) 1982, 1986, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)in_pcb.h 8.1 (Berkeley) 6/10/93
* $FreeBSD$
*/
#ifndef _NETINET6_IN6_PCB_H_
#define _NETINET6_IN6_PCB_H_
#ifdef _KERNEL
#define satosin6(sa) ((struct sockaddr_in6 *)(sa))
#define sin6tosa(sin6) ((struct sockaddr *)(sin6))
#define ifatoia6(ifa) ((struct in6_ifaddr *)(ifa))
struct inpcbgroup *
in6_pcbgroup_byhash(struct inpcbinfo *, u_int, uint32_t);
struct inpcbgroup *
in6_pcbgroup_byinpcb __P((struct inpcb *));
struct inpcbgroup *
in6_pcbgroup_bymbuf(struct inpcbinfo *, struct mbuf *);
struct inpcbgroup *
in6_pcbgroup_bytuple __P((struct inpcbinfo *, const struct in6_addr *,
u_short, const struct in6_addr *, u_short));
void in6_pcbpurgeif0 __P((struct inpcbinfo *, struct ifnet *));
void in6_losing __P((struct inpcb *));
int in6_pcbbind __P((struct inpcb *, struct sockaddr *, struct ucred *));
int in6_pcbconnect __P((struct inpcb *, struct sockaddr *, struct ucred *));
int in6_pcbconnect_mbuf __P((struct inpcb *, struct sockaddr *,
struct ucred *, struct mbuf *));
void in6_pcbdisconnect __P((struct inpcb *));
int in6_pcbladdr(struct inpcb *, struct sockaddr *, struct in6_addr *);
struct inpcb *
in6_pcblookup_local __P((struct inpcbinfo *,
struct in6_addr *, u_short, int,
struct ucred *));
struct inpcb *
in6_pcblookup __P((struct inpcbinfo *, struct in6_addr *,
u_int, struct in6_addr *, u_int, int,
struct ifnet *));
struct inpcb *
in6_pcblookup_hash_locked __P((struct inpcbinfo *, struct in6_addr *,
u_int, struct in6_addr *, u_int, int,
struct ifnet *));
struct inpcb *
in6_pcblookup_mbuf __P((struct inpcbinfo *, struct in6_addr *,
u_int, struct in6_addr *, u_int, int,
struct ifnet *ifp, struct mbuf *));
void in6_pcbnotify __P((struct inpcbinfo *, struct sockaddr *,
u_int, const struct sockaddr *, u_int, int, void *,
struct inpcb *(*)(struct inpcb *, int)));
struct inpcb *
in6_rtchange __P((struct inpcb *, int));
struct sockaddr *
in6_sockaddr __P((in_port_t port, struct in6_addr *addr_p));
struct sockaddr *
in6_v4mapsin6_sockaddr __P((in_port_t port, struct in_addr *addr_p));
int in6_getpeeraddr __P((struct socket *so, struct sockaddr **nam));
int in6_getsockaddr __P((struct socket *so, struct sockaddr **nam));
int in6_mapped_sockaddr __P((struct socket *so, struct sockaddr **nam));
int in6_mapped_peeraddr __P((struct socket *so, struct sockaddr **nam));
int in6_selecthlim __P((struct in6pcb *, struct ifnet *));
int in6_pcbsetport __P((struct in6_addr *, struct inpcb *, struct ucred *));
void init_sin6 __P((struct sockaddr_in6 *sin6, struct mbuf *m));
#endif /* _KERNEL */
#endif /* !_NETINET6_IN6_PCB_H_ */