linux/net/ipv4
Eric Dumazet f07d960df3 tcp: avoid frag allocation for small frames
tcp_sendmsg() uses select_size() helper to choose skb head size when a
new skb must be allocated.

If GSO is enabled for the socket, current strategy is to force all
payload data to be outside of headroom, in PAGE fragments.

This strategy is not welcome for small packets, wasting memory.

Experiments show that best results are obtained when using 2048 bytes
for skb head (This includes the skb overhead and various headers)

This patch provides better len/truesize ratios for packets sent to
loopback device, and reduce memory needs for in-flight loopback packets,
particularly on arches with big pages.

If a sender sends many 1-byte packets to an unresponsive application,
receiver rmem_alloc will grow faster and will stop queuing these packets
sooner, or will collapse its receive queue to free excess memory.

netperf -t TCP_RR results are improved by ~4 %, and many workloads are
improved as well (tbench, mysql...)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 13:17:03 -05:00
..
netfilter net: dont call jump_label_dec from irq context 2011-11-29 00:26:25 -05:00
af_inet.c net: introduce and use netdev_features_t for device features sets 2011-11-16 17:43:10 -05:00
ah4.c ah: Don't return NET_XMIT_DROP on input. 2011-11-12 18:13:32 -05:00
arp.c ipv4: Remove all uses of LL_ALLOCATED_SPACE 2011-11-18 14:37:08 -05:00
cipso_ipv4.c cipso: remove an unneeded NULL check in cipso_v4_doi_add() 2011-10-11 18:43:53 -04:00
datagram.c ipv4: Lock socket and use cork flow in ip4_datagram_connect(). 2011-05-08 13:48:57 -07:00
devinet.c rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER 2011-08-02 04:29:23 -07:00
esp4.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
fib_frontend.c rtnetlink: Compute and store minimum ifinfo dump size 2011-06-09 20:38:07 -07:00
fib_lookup.h ipv4: Fix nexthop caching wrt. scoping. 2011-03-24 18:06:47 -07:00
fib_rules.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
fib_semantics.c ipv4: Fix fib_info->fib_metrics leak 2011-09-16 17:42:26 -04:00
fib_trie.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
gre.c rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER 2011-08-02 04:29:23 -07:00
icmp.c net: more accurate skb truesize 2011-10-13 16:05:07 -04:00
igmp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2011-11-26 14:47:03 -05:00
inet_connection_sock.c net: rename sk_clone to sk_clone_lock 2011-11-08 17:07:07 -05:00
inet_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2011-11-26 14:47:03 -05:00
inet_fragment.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_hashtables.c net: Compute protocol sequence numbers and fragment IDs using MD5. 2011-08-06 18:33:19 -07:00
inet_lro.c net: add skb frag size accessors 2011-10-19 03:10:46 -04:00
inet_timewait_sock.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
inetpeer.c net: Compute protocol sequence numbers and fragment IDs using MD5. 2011-08-06 18:33:19 -07:00
ip_forward.c ipv4: Save nexthop address of LSRR/SSRR option to IPCB. 2011-11-23 19:19:32 -05:00
ip_fragment.c net: add skb frag size accessors 2011-10-19 03:10:46 -04:00
ip_gre.c ip_gre: Set needed_headroom dynamically again 2011-11-18 14:37:10 -05:00
ip_input.c ip: introduce ip_is_fragment helper inline function 2011-06-21 20:33:34 -07:00
ip_options.c ipv4: Save nexthop address of LSRR/SSRR option to IPCB. 2011-11-23 19:19:32 -05:00
ip_output.c ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT 2011-10-24 03:06:21 -04:00
ip_sockglue.c ipv4: PKTINFO doesnt need dst reference 2011-11-09 16:36:27 -05:00
ipcomp.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
ipconfig.c ipv4: Remove all uses of LL_ALLOCATED_SPACE 2011-11-18 14:37:08 -05:00
ipip.c net: better pcpu data alignment 2011-11-08 15:10:59 -05:00
ipmr.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
Kconfig ipv4: Remove fib_hash. 2011-02-01 15:35:25 -08:00
Makefile net: ipv4: add IPPROTO_ICMP socket kind 2011-05-13 16:08:13 -04:00
netfilter.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
ping.c ping: dont increment ICMP_MIB_INERRORS 2011-11-18 14:38:59 -05:00
proc.c ipv4: reduce percpu needs for icmpmsg mibs 2011-11-09 16:04:20 -05:00
protocol.c net: add __rcu annotations to protocol 2010-10-27 11:37:31 -07:00
raw.c ipv4: Remove all uses of LL_ALLOCATED_SPACE 2011-11-18 14:37:08 -05:00
route.c ipv4: Don't use the cached pmtu informations for input routes 2011-11-26 14:29:52 -05:00
syncookies.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
sysctl_net_ipv4.c inetpeer: remove unused list 2011-06-08 17:05:30 -07:00
tcp_bic.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_cong.c tcp: do not scale TSO segment size with reordering degree 2011-11-29 00:29:41 -05:00
tcp_cubic.c tcp_cubic: limit delayed_ack ratio to prevent divide error 2011-05-08 15:51:57 -07:00
tcp_diag.c tcp: diag: Dont report negative values for rx queue 2009-12-03 16:06:13 -08:00
tcp_highspeed.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_htcp.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_hybla.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_illinois.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_input.c tcp: skip cwnd moderation in TCP_CA_Open in tcp_try_to_open 2011-11-27 18:54:09 -05:00
tcp_ipv4.c tcp: clear xmit timers in tcp_v4_syn_recv_sock() 2011-11-16 16:57:45 -05:00
tcp_lp.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp_minisocks.c net: remove ipv6_addr_copy() 2011-11-22 16:43:32 -05:00
tcp_output.c tcp: do not scale TSO segment size with reordering degree 2011-11-29 00:29:41 -05:00
tcp_probe.c net: ipv4: tcp_probe: cleanup snprintf() use 2010-11-17 12:27:46 -08:00
tcp_scalable.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_timer.c TCP: remove TCP_DEBUG 2011-10-24 17:36:08 -04:00
tcp_vegas.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_vegas.h
tcp_veno.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_westwood.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_yeah.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp.c tcp: avoid frag allocation for small frames 2011-11-29 13:17:03 -05:00
tunnel4.c tunnels: add __rcu annotations 2010-10-27 11:37:32 -07:00
udp_impl.h net: Make setsockopt() optlen be unsigned. 2009-09-30 16:12:20 -07:00
udp.c net: introduce and use netdev_features_t for device features sets 2011-11-16 17:43:10 -05:00
udplite.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
xfrm4_input.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c ipv4: Don't pre-seed hoplimit metric. 2010-12-12 22:08:17 -08:00
xfrm4_output.c xfrm4: Don't call icmp_send on local error 2011-07-01 17:33:19 -07:00
xfrm4_policy.c ipv4: fix ipsec forward performance regression 2011-10-24 03:01:22 -04:00
xfrm4_state.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
xfrm4_tunnel.c net: struct xfrm_tunnel in read_mostly section 2010-08-30 13:50:45 -07:00