From 7262ff6e58b1d30213c744786d6687611d4695c7 Mon Sep 17 00:00:00 2001 From: dg Date: Tue, 27 Jan 1998 09:15:13 +0000 Subject: Improved connection establishment performance by doing local port lookups via a hashed port list. In the new scheme, in_pcblookup() goes away and is replaced by a new routine, in_pcblookup_local() for doing the local port check. Note that this implementation is space inefficient in that the PCB struct is now too large to fit into 128 bytes. I might deal with this in the future by using the new zone allocator, but I wanted these changes to be extensively tested in their current form first. Also: 1) Fixed off-by-one errors in the port lookup loops in in_pcbbind(). 2) Got rid of some unneeded rehashing. Adding a new routine, in_pcbinshash() to do the initialial hash insertion. 3) Renamed in_pcblookuphash() to in_pcblookup_hash() for easier readability. 4) Added a new routine, in_pcbremlists() to remove the PCB from the various hash lists. 5) Added/deleted comments where appropriate. 6) Removed unnecessary splnet() locking. In general, the PCB functions should be called at splnet()...there are unfortunately a few exceptions, however. 7) Reorganized a few structs for better cache line behavior. 8) Killed my TCP_ACK_HACK kludge. It may come back in a different form in the future, however. These changes have been tested on wcarchive for more than a month. In tests done here, connection establishment overhead is reduced by more than 50 times, thus getting rid of one of the major networking scalability problems. Still to do: make tcp_fastimo/tcp_slowtimo scale well for systems with a large number of connections. tcp_fastimo is easy; tcp_slowtimo is difficult. WARNING: Anything that knows about inpcb and tcpcb structs will have to be recompiled; at the very least, this includes netstat(1). --- sys/netinet/tcp_timewait.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'sys/netinet/tcp_timewait.c') diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c index 962dc47..b0bdac2 100644 --- a/sys/netinet/tcp_timewait.c +++ b/sys/netinet/tcp_timewait.c @@ -31,7 +31,7 @@ * SUCH DAMAGE. * * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 - * $Id: tcp_subr.c,v 1.40 1997/12/19 03:36:14 julian Exp $ + * $Id: tcp_subr.c,v 1.41 1998/01/25 04:23:32 eivind Exp $ */ #include "opt_compat.h" @@ -87,11 +87,10 @@ static void tcp_cleartaocache __P((void)); static void tcp_notify __P((struct inpcb *, int)); /* - * Target size of TCP PCB hash table. Will be rounded down to a prime - * number. + * Target size of TCP PCB hash tables. Must be a power of two. */ #ifndef TCBHASHSIZE -#define TCBHASHSIZE 128 +#define TCBHASHSIZE 512 #endif /* @@ -107,6 +106,7 @@ tcp_init() LIST_INIT(&tcb); tcbinfo.listhead = &tcb; tcbinfo.hashbase = hashinit(TCBHASHSIZE, M_PCB, &tcbinfo.hashmask); + tcbinfo.porthashbase = hashinit(TCBHASHSIZE, M_PCB, &tcbinfo.porthashmask); if (max_protohdr < sizeof(struct tcpiphdr)) max_protohdr = sizeof(struct tcpiphdr); if (max_linkhdr + sizeof(struct tcpiphdr) > MHLEN) @@ -417,8 +417,8 @@ tcp_close(tp) } if (tp->t_template) (void) m_free(dtom(tp->t_template)); + inp->inp_ppcb = NULL; free(tp, M_PCB); - inp->inp_ppcb = 0; soisdisconnected(so); in_pcbdetach(inp); tcpstat.tcps_closed++; -- cgit v1.1