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* [TCP]: Send ACKs each 2nd received segment.Alexey Kuznetsov2006-09-221-0/+2
| | | | | | | | | | | | | | | | | It does not affect either mss-sized connections (obviously) or connections controlled by Nagle (because there is only one small segment in flight). The idea is to record the fact that a small segment arrives on a connection, where one small segment has already been received and still not-ACKed. In this case ACK is forced after tcp_recvmsg() drains receive buffer. In other words, it is a "soft" each-2nd-segment ACK, which is enough to preserve ACK clock even when ABC is enabled. Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Fix rcv mss estimate for LROHerbert Xu2006-09-221-1/+1
| | | | | | | | | | | | | | | By passing a Linux-generated TSO packet straight back into Linux, Xen becomes our first LRO user :) Unfortunately, there is at least one spot in our stack that needs to be changed to cope with this. The receive MSS estimate is computed from the raw packet size. This is broken if the packet is GSO/LRO. Fortunately the real MSS can be found in gso_size so we simply need to use that if it is non-zero. Real LRO NICs should of course set the gso_size field in future. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET/IPV4/IPV6]: Change some sysctl variables to __read_mostlyBrian Haley2006-09-221-18/+18
| | | | | | | | | | Change net/core, ipv4 and ipv6 sysctl variables to __read_mostly. Couldn't actually measure any performance increase while testing (.3% I consider noise), but seems like the right thing to do. Signed-off-by: Brian Haley <brian.haley@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Turn ABC off.Stephen Hemminger2006-09-171-1/+1
| | | | | | | | | | Turn Appropriate Byte Count off by default because it unfairly penalizes applications that do small writes. Add better documentation to describe what it is so users will understand why they might want to turn it on. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Two RFC3465 Appropriate Byte Count fixes.Daikichi Osuga2006-08-291-2/+7
| | | | | | | | 1) fix slow start after retransmit timeout 2) fix case of L=2*SMSS acked bytes comparison Signed-off-by: Daikichi Osuga <osugad@s1.nttdocomo.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Fixes IW > 2 cases when TCP is application limitedIlpo Järvinen2006-08-041-1/+2
| | | | | | | | | Whenever a transfer is application limited, we are allowed at least initial window worth of data per window unless cwnd is previously less than that. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-301-1/+0
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [NET]: Add ECN support for TSOMichael Chan2006-06-291-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | In the current TSO implementation, NETIF_F_TSO and ECN cannot be turned on together in a TCP connection. The problem is that most hardware that supports TSO does not handle CWR correctly if it is set in the TSO packet. Correct handling requires CWR to be set in the first packet only if it is set in the TSO header. This patch adds the ability to turn on NETIF_F_TSO and ECN using GSO if necessary to handle TSO packets with CWR set. Hardware that handles CWR correctly can turn on NETIF_F_TSO_ECN in the dev-> features flag. All TSO packets with CWR set will have the SKB_GSO_TCPV4_ECN set. If the output device does not have the NETIF_F_TSO_ECN feature set, GSO will split the packet up correctly with CWR only set in the first segment. With help from Herbert Xu <herbert@gondor.apana.org.au>. Since ECN can always be enabled with TSO, the SOCK_NO_LARGESEND sock flag is completely removed. Signed-off-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Merge TSO/UFO fields in sk_buffHerbert Xu2006-06-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not going to scale if we add any more segmentation methods (e.g., DCCP). So let's merge them. They were used to tell the protocol of a packet. This function has been subsumed by the new gso_type field. This is essentially a set of netdev feature bits (shifted by 16 bits) that are required to process a specific skb. As such it's easy to tell whether a given device can process a GSO skb: you just have to and the gso_type field and the netdev's features field. I've made gso_type a conjunction. The idea is that you have a base type (e.g., SKB_GSO_TCPV4) that can be modified further to support new features. For example, if we add a hardware TSO type that supports ECN, they would declare NETIF_F_TSO | NETIF_F_TSO_ECN. All TSO packets with CWR set would have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO packets would be SKB_GSO_TCPV4. This means that only the CWR packets need to be emulated in software. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Minimum congestion window consolidation.Stephen Hemminger2006-06-171-2/+11
| | | | | | | | | | | | | | Many of the TCP congestion methods all just use ssthresh as the minimum congestion window on decrease. Rather than duplicating the code, just have that be the default if that handle in the ops structure is not set. Minor behaviour change to TCP compound. It probably wants to use this (ssthresh) as lower bound, rather than ssthresh/2 because the latter causes undershoot on loss. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: tcp_rcv_rtt_measure_ts() call in pure-ACK path is superfluousDavid S. Miller2006-06-171-2/+0
| | | | | | | | | We only want to take receive RTT mesaurements for data bearing frames, here in the header prediction fast path for a pure-sender, we know that we have a pure-ACK and thus the checks in tcp_rcv_rtt_mesaure_ts() will not pass. Signed-off-by: David S. Miller <davem@davemloft.net>
* [I/OAT]: TCP recv offload to I/OATChris Leech2006-06-171-7/+67
| | | | | | | | Locks down user pages and sets up for DMA in tcp_recvmsg, then calls dma_async_try_early_copy in tcp_v4_do_rcv Signed-off-by: Chris Leech <christopher.leech@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: continued: reno sacked_out count fixAki M Nyrhinen2006-06-111-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From: Aki M Nyrhinen <anyrhine@cs.helsinki.fi> IMHO the current fix to the problem (in_flight underflow in reno) is incorrect. it treats the symptons but ignores the problem. the problem is timing out packets other than the head packet when we don't have sack. i try to explain (sorry if explaining the obvious). with sack, scanning the retransmit queue for timed out packets is fine because we know which packets in our retransmit queue have been acked by the receiver. without sack, we know only how many packets in our retransmit queue the receiver has acknowledged, but no idea which packets. think of a "typical" slow-start overshoot case, where for example every third packet in a window get lost because a router buffer gets full. with sack, we check for timeouts on those every third packet (as the rest have been sacked). the packet counting works out and if there is no reordering, we'll retransmit exactly the packets that were lost. without sack, however, we check for timeout on every packet and end up retransmitting consecutive packets in the retransmit queue. in our slow-start example, 2/3 of those retransmissions are unnecessary. these unnecessary retransmissions eat the congestion window and evetually prevent fast recovery from continuing, if enough packets were lost. Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: reno sacked_out count fixAngelo P. Castellani2006-05-161-0/+2
| | | | | | | | | | | | | | | | | | | | | From: "Angelo P. Castellani" <angelo.castellani+lkml@gmail.com> Using NewReno, if a sk_buff is timed out and is accounted as lost_out, it should also be removed from the sacked_out. This is necessary because recovery using NewReno fast retransmit could take up to a lot RTTs and the sk_buff RTO can expire without actually being really lost. left_out = sacked_out + lost_out in_flight = packets_out - left_out + retrans_out Using NewReno without this patch, on very large network losses, left_out becames bigger than packets_out + retrans_out (!!). For this reason unsigned integer in_flight overflows to 2^32 - something. Signed-off-by: David S. Miller <davem@davemloft.net>
* [IPV4]: Possible cleanups.Adrian Bunk2006-04-141-1/+0
| | | | | | | | | | | | | | | | | | | This patch contains the following possible cleanups: - make the following needlessly global function static: - arp.c: arp_rcv() - remove the following unused EXPORT_SYMBOL's: - devinet.c: devinet_ioctl - fib_frontend.c: ip_rt_ioctl - inet_hashtables.c: inet_bind_bucket_create - inet_hashtables.c: inet_bind_hash - tcp_input.c: sysctl_tcp_abc - tcp_ipv4.c: sysctl_tcp_tw_reuse - tcp_output.c: sysctl_tcp_mtu_probing - tcp_output.c: sysctl_tcp_base_mss Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP] mtu probing: move tcp-specific data out of inet_connection_sockJohn Heffner2006-03-201-2/+2
| | | | | | | | This moves some TCP-specific MTU probing state out of inet_connection_sock back to tcp_sock. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: MTU probingJohn Heffner2006-03-201-0/+49
| | | | | | | | | Implementation of packetization layer path mtu discovery for TCP, based on the internet-draft currently found at <http://www.ietf.org/internet-drafts/draft-ietf-pmtud-method-05.txt>. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: rcvbuf lock when tcp_moderate_rcvbuf enabledJohn Heffner2006-02-091-1/+2
| | | | | | | The rcvbuf lock should probably be honored here. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Change some "if (x) BUG();" to "BUG_ON(x);"Kris Katterjohn2006-01-091-1/+1
| | | | | | | This changes some simple "if (x) BUG();" statements to "BUG_ON(x);" Signed-off-by: Kris Katterjohn <kjak@users.sourceforge.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: less inline'sStephen Hemminger2006-01-031-21/+61
| | | | | | | | | | | | | | | | | | | | | TCP inline usage cleanup: * get rid of inline in several places * replace __inline__ with inline where possible * move functions used in one file out of tcp.h * let compiler decide on used once cases On x86_64: text data bss dec hex filename 3594701 648348 567400 4810449 4966d1 vmlinux.orig 3593133 648580 567400 4809113 496199 vmlinux On sparc64: text data bss dec hex filename 2538278 406152 530392 3474822 350586 vmlinux.ORIG 2536382 406384 530392 3473158 34ff06 vmlinux Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [IP_SOCKGLUE]: Remove most of the tcp specific callsArnaldo Carvalho de Melo2006-01-031-6/+4
| | | | | | | | | | | | | | As DCCP needs to be called in the same spots. Now we have a member in inet_sock (is_icsk), set at sock creation time from struct inet_protosw->flags (if INET_PROTOSW_ICSK is set, like for TCP and DCCP) to see if a struct sock instance is a inet_connection_sock for places like the ones in ip_sockglue.c (v4 and v6) where we previously were looking if sk_type was SOCK_STREAM, that is insufficient because we now use the same code for DCCP, that has sk_type SOCK_DCCP. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [ICSK]: Rename struct tcp_func to struct inet_connection_sock_af_opsArnaldo Carvalho de Melo2006-01-031-5/+6
| | | | | | | | And move it to struct inet_connection_sock. DCCP will use it in the upcoming changesets. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: More spelling fixes.Stephen Hemminger2005-11-151-2/+2
| | | | | | | From Joe Perches Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: speed up SACK processingStephen Hemminger2005-11-101-15/+129
| | | | | | | | | Use "hints" to speed up the SACK processing. Various forms of this have been used by TCP developers (Web100, STCP, BIC) to avoid the 2x linear search of outstanding segments. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: spelling fixesStephen Hemminger2005-11-101-20/+20
| | | | | | | Minor spelling fixes for TCP code. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: receive buffer growth limiting with mixed MTUJohn Heffner2005-11-101-27/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a patch for discussion addressing some receive buffer growing issues. This is partially related to the thread "Possible BUG in IPv4 TCP window handling..." last week. Specifically it addresses the problem of an interaction between rcvbuf moderation (receiver autotuning) and rcv_ssthresh. The problem occurs when sending small packets to a receiver with a larger MTU. (A very common case I have is a host with a 1500 byte MTU sending to a host with a 9k MTU.) In such a case, the rcv_ssthresh code is targeting a window size corresponding to filling up the current rcvbuf, not taking into account that the new rcvbuf moderation may increase the rcvbuf size. One hunk makes rcv_ssthresh use tcp_rmem[2] as the size target rather than rcvbuf. The other changes the behavior when it overflows its memory bounds with in-order data so that it tries to grow rcvbuf (the same as with out-of-order data). These changes should help my problem of mixed MTUs, and should also help the case from last week's thread I think. (In both cases though you still need tcp_rmem[2] to be set much larger than the TCP window.) One question is if this is too aggressive at trying to increase rcvbuf if it's under memory stress. Orignally-from: John Heffner <jheffner@psc.edu> Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Appropriate Byte Count supportStephen Hemminger2005-11-101-0/+7
| | | | | | | | | | | | | This is an updated version of the RFC3465 ABC patch originally for Linux 2.6.11-rc4 by Yee-Ting Li. ABC is a way of counting bytes ack'd rather than packets when updating congestion control. The orignal ABC described in the RFC applied to a Reno style algorithm. For advanced congestion control there is little change after leaving slow start. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: simplify microsecond rtt samplingStephen Hemminger2005-11-101-32/+30
| | | | | | | | | Simplify the code that comuputes microsecond rtt estimate used by TCP Vegas. Move the callback out of the RTT sampler and into the end of the ack cleanup. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Clear stale pred_flags when snd_wnd changesHerbert Xu2005-10-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This bug is responsible for causing the infamous "Treason uncloaked" messages that's been popping up everywhere since the printk was added. It has usually been blamed on foreign operating systems. However, some of those reports implicate Linux as both systems are running Linux or the TCP connection is going across the loopback interface. In fact, there really is a bug in the Linux TCP header prediction code that's been there since at least 2.1.8. This bug was tracked down with help from Dale Blount. The effect of this bug ranges from harmless "Treason uncloaked" messages to hung/aborted TCP connections. The details of the bug and fix is as follows. When snd_wnd is updated, we only update pred_flags if tcp_fast_path_check succeeds. When it fails (for example, when our rcvbuf is used up), we will leave pred_flags with an out-of-date snd_wnd value. When the out-of-date pred_flags happens to match the next incoming packet we will again hit the fast path and use the current snd_wnd which will be wrong. In the case of the treason messages, it just happens that the snd_wnd cached in pred_flags is zero while tp->snd_wnd is non-zero. Therefore when a zero-window packet comes in we incorrectly conclude that the window is non-zero. In fact if the peer continues to send us zero-window pure ACKs we will continue making the same mistake. It's only when the peer transmits a zero-window packet with data attached that we get a chance to snap out of it. This is what triggers the treason message at the next retransmit timeout. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [TCP]: Don't over-clamp window in tcp_clamp_window()Alexey Kuznetsov2005-09-291-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Handle better the case where the sender sends full sized frames initially, then moves to a mode where it trickles out small amounts of data at a time. This known problem is even mentioned in the comments above tcp_grow_window() in tcp_input.c, specifically: ... * The scheme does not work when sender sends good segments opening * window and then starts to feed us spagetti. But it should work * in common situations. Otherwise, we have to rely on queue collapsing. ... When the sender gives full sized frames, the "struct sk_buff" overhead from each packet is small. So we'll advertize a larger window. If the sender moves to a mode where small segments are sent, this ratio becomes tilted to the other extreme and we start overrunning the socket buffer space. tcp_clamp_window() tries to address this, but it's clamping of tp->window_clamp is a wee bit too aggressive for this particular case. Fix confirmed by Ion Badulescu. Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Compute in_sacked properly when we split up a TSO frame.Herbert Xu2005-09-141-7/+9
| | | | | | | | | | | | | The problem is that the SACK fragmenting code may incorrectly call tcp_fragment() with a length larger than the skb->len. This happens when the skb on the transmit queue completely falls to the LHS of the SACK. And add a BUG() check to tcp_fragment() so we can spot this kind of error more quickly in the future. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Keep TSO enabled even during loss events.David S. Miller2005-09-011-12/+24
| | | | | | | | | | All we need to do is resegment the queue so that we record SACK information accurately. The edges of the SACK blocks guide our resegmenting decisions. With help from Herbert Xu. Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Fix sparse warningsArnaldo Carvalho de Melo2005-08-291-1/+1
| | | | | | | | | | | Of this type, mostly: CHECK net/ipv6/netfilter.c net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static? net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static? Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Store skb->timestamp as offset to a base timestampPatrick McHardy2005-08-291-3/+7
| | | | | | | Reduces skb size by 8 bytes on 64-bit. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [ICSK]: Move TCP congestion avoidance members to icskArnaldo Carvalho de Melo2005-08-291-99/+124
| | | | | | | | | | | | | | | | | | | | | This changeset basically moves tcp_sk()->{ca_ops,ca_state,etc} to inet_csk(), minimal renaming/moving done in this changeset to ease review. Most of it is just changes of struct tcp_sock * to struct sock * parameters. With this we move to a state closer to two interesting goals: 1. Generalisation of net/ipv4/tcp_diag.c, becoming inet_diag.c, being used for any INET transport protocol that has struct inet_hashinfo and are derived from struct inet_connection_sock. Keeps the userspace API, that will just not display DCCP sockets, while newer versions of tools can support DCCP. 2. INET generic transport pluggable Congestion Avoidance infrastructure, using the current TCP CA infrastructure with DCCP. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [ICSK]: Introduce reqsk_queue_prune from code in tcp_synack_timerArnaldo Carvalho de Melo2005-08-291-3/+8
| | | | | | | | | | With this we're very close to getting all of the current TCP refactorings in my dccp-2.6 tree merged, next changeset will export some functions needed by the current DCCP code and then dccp-2.6.git will be born! Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Just move the inet_connection_sock function from tcp sourcesArnaldo Carvalho de Melo2005-08-291-4/+6
| | | | | | | | | Completing the previous changeset, this also generalises tcp_v4_synq_add, renaming it to inet_csk_reqsk_queue_hash_add, already geing used in the DCCP tree, which I plan to merge RSN. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Introduce inet_connection_sockArnaldo Carvalho de Melo2005-08-291-128/+138
| | | | | | | | | | | | | | This creates struct inet_connection_sock, moving members out of struct tcp_sock that are shareable with other INET connection oriented protocols, such as DCCP, that in my private tree already uses most of these members. The functions that operate on these members were renamed, using a inet_csk_ prefix while not being moved yet to a new file, so as to ease the review of these changes. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Kill skb->listDavid S. Miller2005-08-291-13/+16
| | | | | | | | | | | | | | Remove the "list" member of struct sk_buff, as it is entirely redundant. All SKB list removal callers know which list the SKB is on, so storing this in sk_buff does nothing other than taking up some space. Two tricky bits were SCTP, which I took care of, and two ATM drivers which Francois Romieu <romieu@fr.zoreil.com> fixed up. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
* [NET]: Transform skb_queue_len() binary tests into skb_queue_empty()David S. Miller2005-07-081-6/+5
| | | | | | | | | | | | | This is part of the grand scheme to eliminate the qlen member of skb_queue_head, and subsequently remove the 'list' member of sk_buff. Most users of skb_queue_len() want to know if the queue is empty or not, and that's trivially done with skb_queue_empty() which doesn't use the skb_queue_head->qlen member and instead uses the queue list emptyness as the test. Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Move to new TSO segmenting scheme.David S. Miller2005-07-051-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | Make TSO segment transmit size decisions at send time not earlier. The basic scheme is that we try to build as large a TSO frame as possible when pulling in the user data, but the size of the TSO frame output to the card is determined at transmit time. This is guided by tp->xmit_size_goal. It is always set to a multiple of MSS and tells sendmsg/sendpage how large an SKB to try and build. Later, tcp_write_xmit() and tcp_push_one() chop up the packet if necessary and conditions warrant. These routines can also decide to "defer" in order to wait for more ACKs to arrive and thus allow larger TSO frames to be emitted. A general observation is that TSO elongates the pipe, thus requiring a larger congestion window and larger buffering especially at the sender side. Therefore, it is important that applications 1) get a large enough socket send buffer (this is accomplished by our dynamic send buffer expansion code) 2) do large enough writes. Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Break out send buffer expansion test.David S. Miller2005-07-051-4/+23
| | | | | | | This makes it easier to understand, and allows easier tweaking of the heuristic later on. Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Do not call tcp_tso_acked() if no work to do.David S. Miller2005-07-051-1/+2
| | | | | | | In tcp_clean_rtx_queue(), if the TSO packet is not even partially acked, do not waste time calling tcp_tso_acked(). Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Kill bogus comment above tcp_tso_acked().David S. Miller2005-07-051-9/+0
| | | | | | | | Everything stated there is out of data. tcp_trim_skb() does adjust the available socket send buffer space and skb->truesize now. Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Fix __tcp_push_pending_frames() 'nonagle' handling.David S. Miller2005-07-051-10/+7
| | | | | | | | | | | | | | | | | | | | | 'nonagle' should be passed to the tcp_snd_test() function as 'TCP_NAGLE_PUSH' if we are checking an SKB not at the tail of the write_queue. This is because Nagle does not apply to such frames since we cannot possibly tack more data onto them. However, while doing this __tcp_push_pending_frames() makes all of the packets in the write_queue use this modified 'nonagle' value. Fix the bug and simplify this function by just calling tcp_write_xmit() directly if sk_send_head is non-NULL. As a result, we can now make tcp_data_snd_check() just call tcp_push_pending_frames() instead of the specialized __tcp_data_snd_check(). Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Move __tcp_data_snd_check into tcp_output.cDavid S. Miller2005-07-051-10/+0
| | | | | | | | It reimplements portions of tcp_snd_check(), so it we move it to tcp_output.c we can consolidate it's logic much easier in a later change. Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Add pluggable congestion control algorithm infrastructure.Stephen Hemminger2005-06-231-684/+53
| | | | | | | | | | Allow TCP to have multiple pluggable congestion control algorithms. Algorithms are defined by a set of operations and can be built in or modules. The legacy "new RENO" algorithm is used as a starting point and fallback. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Fix stretch ACK performance killer when doing ucopy.David S. Miller2005-05-231-10/+1
| | | | | | | | | | | | | | | | When we are doing ucopy, we try to defer the ACK generation to cleanup_rbuf(). This works most of the time very well, but if the ucopy prequeue is large, this ACKing behavior kills performance. With TSO, it is possible to fill the prequeue so large that by the time the ACK is sent and gets back to the sender, most of the window has emptied of data and performance suffers significantly. This behavior does help in some cases, so we should think about re-enabling this trick in the future, using some kind of limit in order to avoid the bug case. Signed-off-by: David S. Miller <davem@davemloft.net>
* [PATCH] update Ross Biro bouncing email addressJesper Juhl2005-05-051-1/+1
| | | | | | | | | Ross moved. Remove the bad email address so people will find the correct one in ./CREDITS. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [TCP]: Trivial tcp_data_queue() cleanupJames Morris2005-04-251-1/+0
| | | | | | | | This patch removes a superfluous intialization from tcp_data_queue(). Signed-off-by: James Morris <jmorris@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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