1
linux/net/ipv4
Eric Dumazet eec4df9885 ipv4: speedup inet_dump_ifaddr()
Stephen Hemminger a écrit :
> On Thu, 12 Nov 2009 15:11:36 +0100
> Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
>> When handling large number of netdevices, inet_dump_ifaddr()
>> is very slow because it has O(N^2) complexity.
>>
>> Instead of scanning one single list, we can use the NETDEV_HASHENTRIES
>> sub lists of the dev_index hash table, and RCU lookups.
>>
>> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
>
> You might be able to make RCU critical section smaller by moving
> it into loop.
>

Indeed. But we dump at most one skb (<= 8192 bytes ?), so rcu_read_lock
holding time is small, unless we meet many netdevices without
addresses. I wonder if its really common...

Thanks

[PATCH net-next-2.6] ipv4: speedup inet_dump_ifaddr()

When handling large number of netdevices, inet_dump_ifaddr()
is very slow because it has O(N2) complexity.

Instead of scanning one single list, we can use the NETDEV_HASHENTRIES
sub lists of the dev_index hash table, and RCU lookups.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-13 20:46:55 -08:00
..
netfilter Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-11-06 00:55:55 -08:00
af_inet.c net: check kern before calling security subsystem 2009-11-05 22:18:18 -08:00
ah4.c ah4: convert to ahash 2009-10-18 21:31:59 -07:00
arp.c net: make neigh_ops constant 2009-09-01 17:40:57 -07:00
cipso_ipv4.c ipv4: Define cipso_v4_delopt static 2009-10-07 14:45:58 -07:00
datagram.c inet: rename some inet_sock fields 2009-10-18 18:52:53 -07:00
devinet.c ipv4: speedup inet_dump_ifaddr() 2009-11-13 20:46:55 -08:00
esp4.c net: constify struct net_protocol 2009-09-14 17:03:01 -07:00
fib_frontend.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-11-06 00:55:55 -08:00
fib_hash.c ipv4: fib table algorithm performance improvement 2009-10-05 00:21:56 -07:00
fib_lookup.h ipv4: cleanup - remove two unused parameters from fib_semantic_match(). 2009-05-18 15:16:37 -07:00
fib_rules.c ipv4: fib table algorithm performance improvement 2009-10-05 00:21:56 -07:00
fib_semantics.c ipv4: cleanup - remove two unused parameters from fib_semantic_match(). 2009-05-18 15:16:37 -07:00
fib_trie.c ipv4: fib table algorithm performance improvement 2009-10-05 00:21:56 -07:00
icmp.c icmp: icmp_send() can avoid a dev_put() 2009-11-01 23:55:10 -08:00
igmp.c igmp: Use next_net_device_rcu() 2009-11-13 20:38:49 -08:00
inet_connection_sock.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-10-27 01:03:26 -07:00
inet_diag.c inet: rename some inet_sock fields 2009-10-18 18:52:53 -07:00
inet_fragment.c inet fragments: fix sparse warning: context imbalance 2009-02-26 23:13:35 -08:00
inet_hashtables.c inet: rename some inet_sock fields 2009-10-18 18:52:53 -07:00
inet_lro.c include/net net/ - csum_partial - remove unnecessary casts 2008-11-19 15:44:53 -08:00
inet_timewait_sock.c inet: rename some inet_sock fields 2009-10-18 18:52:53 -07:00
inetpeer.c
ip_forward.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
ip_fragment.c ip_frag: dont touch device refcount 2009-11-05 22:34:22 -08:00
ip_gre.c net: Support specifying the network namespace upon device creation. 2009-11-08 00:53:51 -08:00
ip_input.c inet: rename some inet_sock fields 2009-10-18 18:52:53 -07:00
ip_options.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
ip_output.c inet: rename some inet_sock fields 2009-10-18 18:52:53 -07:00
ip_sockglue.c net: Cleanup redundant tests on unsigned 2009-10-29 01:39:54 -07:00
ipcomp.c net: constify struct net_protocol 2009-09-14 17:03:01 -07:00
ipconfig.c ipv4: teach ipconfig about the MTU option in DHCP 2009-05-19 15:36:17 -07:00
ipip.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-11-08 23:00:54 -08:00
ipmr.c ipmr: Optimize multiple unregistration 2009-10-29 01:13:49 -07:00
Kconfig ipv4: update ARPD help text 2009-06-13 23:36:32 -07:00
Makefile
netfilter.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
proc.c snmp: add missing counters for RFC 4293 2009-04-27 02:45:02 -07:00
protocol.c net: constify struct net_protocol 2009-09-14 17:03:01 -07:00
raw.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-10-29 21:28:59 -07:00
route.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-11-06 00:55:55 -08:00
syncookies.c Allow tcp_parse_options to consult dst entry 2009-10-29 01:28:41 -07:00
sysctl_net_ipv4.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
tcp_bic.c tcp: add helper for AI algorithm 2009-03-02 03:00:15 -08:00
tcp_cong.c Networking: use CAP_NET_ADMIN when deciding to call request_module 2009-08-14 11:18:34 +10:00
tcp_cubic.c tcp: add helper for AI algorithm 2009-03-02 03:00:15 -08:00
tcp_diag.c net: inet_diag_handler structs can be const 2008-11-19 15:43:27 -08:00
tcp_highspeed.c
tcp_htcp.c htcp: merge icsk_ca_state compare 2009-03-02 03:00:14 -08:00
tcp_hybla.c
tcp_illinois.c
tcp_input.c net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED 2009-11-13 20:38:48 -08:00
tcp_ipv4.c net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED 2009-11-13 20:38:48 -08:00
tcp_lp.c
tcp_minisocks.c net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED 2009-11-13 20:38:48 -08:00
tcp_output.c Allow to turn off TCP window scale opt per route 2009-10-29 01:28:47 -07:00
tcp_probe.c inet: rename some inet_sock fields 2009-10-18 18:52:53 -07:00
tcp_scalable.c tcp: add helper for AI algorithm 2009-03-02 03:00:15 -08:00
tcp_timer.c net: Fix for dst_negative_advice 2009-10-20 18:55:46 -07:00
tcp_vegas.c tcp: tcp_vegas ssthresh bugfix 2009-05-25 22:44:59 -07:00
tcp_vegas.h
tcp_veno.c tcp: add helper for AI algorithm 2009-03-02 03:00:15 -08:00
tcp_westwood.c
tcp_yeah.c tcp: add helper for AI algorithm 2009-03-02 03:00:15 -08:00
tcp.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-10-27 01:03:26 -07:00
tunnel4.c net: constify struct net_protocol 2009-09-14 17:03:01 -07:00
udp_impl.h net: Make setsockopt() optlen be unsigned. 2009-09-30 16:12:20 -07:00
udp.c udp: bind() optimisation 2009-11-10 20:54:38 -08:00
udplite.c net: drop capability from protocol definitions 2009-11-05 21:40:17 -08:00
xfrm4_input.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
xfrm4_output.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
xfrm4_policy.c xfrm4: fix build when SYSCTLs are disabled 2009-08-04 20:18:33 -07:00
xfrm4_state.c xfrm: remove useless forward declarations 2008-11-25 01:05:54 -08:00
xfrm4_tunnel.c