linux/include/net
Eric Dumazet dbca9b2750 [NET]: change layout of ehash table
ehash table layout is currently this one :

First half of this table is used by sockets not in TIME_WAIT state
Second half of it is used by sockets in TIME_WAIT state.

This is non optimal because of for a given hash or socket, the two chain heads 
are located in separate cache lines.
Moreover the locks of the second half are never used.

If instead of this halving, we use two list heads in inet_ehash_bucket instead 
of only one, we probably can avoid one cache miss, and reduce ram usage, 
particularly if sizeof(rwlock_t) is big (various CONFIG_DEBUG_SPINLOCK, 
CONFIG_DEBUG_LOCK_ALLOC settings). So we still halves the table but we keep 
together related chains to speedup lookups and socket state change.

In this patch I did not try to align struct inet_ehash_bucket, but a future 
patch could try to make this structure have a convenient size (a power of two 
or a multiple of L1_CACHE_SIZE).
I guess rwlock will just vanish as soon as RCU is plugged into ehash :) , so 
maybe we dont need to scratch our heads to align the bucket...

Note : In case struct inet_ehash_bucket is not a power of two, we could 
probably change alloc_large_system_hash() (in case it use __get_free_pages()) 
to free the unused space. It currently allocates a big zone, but the last 
quarter of it could be freed. Again, this should be a temporary 'problem'.

Patch tested on ipv4 tcp only, but should be OK for IPV6 and DCCP.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08 14:16:46 -08:00
..
bluetooth [PATCH] hci endianness annotations 2006-12-13 09:05:52 -08:00
irda [PATCH] tty: switch to ktermios and new framework 2006-12-08 08:28:56 -08:00
iucv [S390]: Add AF_IUCV socket support 2007-02-08 13:51:54 -08:00
netfilter [NETFILTER]: NAT: optional source port randomization support 2007-02-08 12:39:17 -08:00
sctp [SCTP]: Correctly handle unexpected INIT-ACK chunk. 2007-01-23 20:25:46 -08:00
tc_act
tipc [TIPC]: endianness annotations 2006-12-02 21:21:08 -08:00
act_api.h
addrconf.h [IPV6]: Misc endianness annotations. 2006-12-02 21:22:52 -08:00
af_unix.h
ah.h
arp.h [IPV6]: Assorted trivial endianness annotations. 2006-12-02 21:22:50 -08:00
atmclip.h [ATM]: Annotations. 2006-12-02 21:22:55 -08:00
ax25.h [AX.25]: Fix unchecked ax25_linkfail_register uses 2006-12-17 21:59:11 -08:00
checksum.h [NET]: Make mangling a checksum (0 -> 0xffff on the wire) explicit. 2006-12-02 21:23:39 -08:00
cipso_ipv4.h NetLabel: use the correct CIPSOv4 MLS label limits 2006-12-02 21:24:12 -08:00
compat.h
datalink.h
dn_dev.h
dn_fib.h
dn_neigh.h
dn_nsp.h
dn_route.h
dn.h
dsfield.h [NET]: IP header modifier helpers annotations. 2006-12-02 21:23:40 -08:00
dst.h [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
esp.h
fib_rules.h [NETLINK]: Do precise netlink message allocations where possible 2006-12-02 21:22:11 -08:00
flow.h [NET]: Rethink mark field in struct flowi 2006-12-02 21:21:39 -08:00
gen_stats.h
genetlink.h [GENETLINK]: Add cmd dump completion. 2006-12-02 21:32:09 -08:00
icmp.h
ieee80211_crypt.h
ieee80211_radiotap.h
ieee80211.h [PATCH] ieee80211: WLAN_GET_SEQ_SEQ fix (select correct region) 2007-01-02 20:56:26 -05:00
ieee80211softmac_wx.h
ieee80211softmac.h WorkStruct: make allyesconfig 2006-11-22 14:57:56 +00:00
if_inet6.h [IPV6]: Per-interface statistics support. 2006-12-02 21:22:08 -08:00
inet6_connection_sock.h [TCP]: Restore SKB socket owner setting in tcp_transmit_skb(). 2007-01-26 01:04:55 -08:00
inet6_hashtables.h [IPV6]: annotate inet6_hashtables 2006-12-02 21:21:10 -08:00
inet_common.h
inet_connection_sock.h [TCP]: Restore SKB socket owner setting in tcp_transmit_skb(). 2007-01-26 01:04:55 -08:00
inet_ecn.h [NET]: IP header modifier helpers annotations. 2006-12-02 21:23:40 -08:00
inet_hashtables.h [NET]: change layout of ehash table 2007-02-08 14:16:46 -08:00
inet_sock.h
inet_timewait_sock.h WorkStruct: Pass the work_struct pointer instead of context data 2006-11-22 14:55:48 +00:00
inetpeer.h
ip6_checksum.h [IPV6]: Dumb typo in generic csum_ipv6_magic() 2006-12-22 11:12:07 -08:00
ip6_fib.h [IPV6]: Make fib6_node subtree depend on IPV6_SUBTREES 2006-12-13 16:48:31 -08:00
ip6_route.h [IPV6]: Misc endianness annotations. 2006-12-02 21:22:52 -08:00
ip6_tunnel.h
ip_fib.h [IPV4] nl_fib_lookup: Rename fl_fwmark to fl_mark 2006-12-02 21:21:40 -08:00
ip_mp_alg.h [NET]: Rethink mark field in struct flowi 2006-12-02 21:21:39 -08:00
ip_vs.h [NET]: ipvs checksum annotations. 2006-12-02 21:23:41 -08:00
ip.h [TCP]: Restore SKB socket owner setting in tcp_transmit_skb(). 2007-01-26 01:04:55 -08:00
ipcomp.h
ipconfig.h [NET]: ipconfig and nfsroot annotations 2006-12-02 21:21:09 -08:00
ipip.h [IPV6] net/ipv6/sit.c: make 2 functions static 2006-12-02 21:26:15 -08:00
ipv6.h [IPV6]: __ipv6_addr_diff() annotations and cleanup. 2006-12-02 21:22:53 -08:00
ipx.h
iw_handler.h
lapb.h
llc_c_ac.h
llc_c_ev.h
llc_c_st.h
llc_conn.h
llc_if.h
llc_pdu.h [LLC]: anotations 2006-12-02 21:21:23 -08:00
llc_s_ac.h
llc_s_ev.h
llc_s_st.h
llc_sap.h
llc.h
mip6.h
ndisc.h [IPV6]: Misc endianness annotations. 2006-12-02 21:22:52 -08:00
neighbour.h [NET]: Convert hh_lock to seqlock. 2006-12-08 17:19:20 -08:00
netdma.h
netevent.h
netlabel.h NetLabel: convert to an extensibile/sparse category bitmap 2006-12-02 21:31:36 -08:00
netlink.h [PATCH] severing skbuff.h -> mm.h 2006-12-04 02:00:34 -05:00
netrom.h
nexthop.h
p8022.h
pkt_cls.h
pkt_sched.h
protocol.h [INET]: Change protocol field in struct inet_protosw to u16 2006-12-02 21:30:55 -08:00
psnap.h
raw.h
rawv6.h [IPV6]: 'info' argument of ipv6 ->err_handler() is net-endian 2006-12-02 21:21:12 -08:00
red.h
request_sock.h [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
rose.h [AX.25]: Fix unchecked rose_add_loopback_neigh uses 2006-12-17 21:59:14 -08:00
route.h [IPV4/IPV6]: Always wait for IPSEC SA resolution in socket contexts. 2007-02-08 12:38:45 -08:00
sch_generic.h [NET_SCHED]: Fix endless loops caused by inaccurate qlen counters (part 1) 2006-12-02 21:31:42 -08:00
scm.h
slhc_vj.h
snmp.h
sock.h [PATCH] lockdep: annotate nfs/nfsd in-kernel sockets 2006-12-07 08:39:30 -08:00
syncppp.h
tcp_ecn.h
tcp_states.h
tcp.h [TCP]: remove tcp header from tcp_v4_check (take #2) 2007-02-08 12:38:44 -08:00
timewait_sock.h [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
transp_v6.h [NET]: Supporting UDP-Lite (RFC 3828) in Linux 2006-12-02 21:22:46 -08:00
udp.h [PATCH] severing skbuff.h -> poll.h 2006-12-04 02:00:31 -05:00
udplite.h [NET]: Fix assorted misannotations (from md5 and udplite merges). 2006-12-02 21:27:16 -08:00
x25.h [X.25]: Adds /proc/sys/net/x25/x25_forward to control forwarding. 2007-02-08 13:34:36 -08:00
x25device.h
xfrm.h [XFRM]: Extension for dynamic update of endpoint address(es) 2007-02-08 13:11:42 -08:00