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2008-04-21tcp: Make use of before macro in tcp_input.cArnd Hannemann
Make use of tcp before macro. Signed-off-by: Arnd Hannemann <hannemann@nets.rwth-aachen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-17Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
2008-04-15[TCP]: Add return value indication to tcp_prune_ofo_queue().Vitaliy Gusev
Returns non-zero if tp->out_of_order_queue was seen non-empty. This allows tcp_try_rmem_schedule() to return early. Signed-off-by: Vitaliy Gusev <vgusev@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-15[TCP]: Fix never pruned tcp out-of-order queue.Vitaliy Gusev
tcp_prune_queue() doesn't prune an out-of-order queue at all. Therefore sk_rmem_schedule() can fail but the out-of-order queue isn't pruned . This can lead to tcp deadlock state if the next two conditions are held: 1. There are a sequence hole between last received in order segment and segments enqueued to the out-of-order queue. 2. Size of all segments in the out-of-order queue is more than tcp_mem[2]. Signed-off-by: Vitaliy Gusev <vgusev@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-14[TCP]: Format addresses appropriately in debug messages.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-14[IPV4]: Use NIPQUAD_FMT to format ipv4 addresses.YOSHIFUJI Hideaki
And use %u to format port. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-14Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/ehea/ehea_main.c drivers/net/wireless/iwlwifi/Kconfig drivers/net/wireless/rt2x00/rt61pci.c net/ipv4/inet_timewait_sock.c net/ipv6/raw.c net/mac80211/ieee80211_sta.c
2008-04-14[SKB]: __skb_append = __skb_queue_after Gerrit Renker
This expresses __skb_append in terms of __skb_queue_after, exploiting that __skb_append(old, new, list) = __skb_queue_after(list, old, new). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-07[TCP]: Don't allow FRTO to take place while MTU is being probedIlpo Järvinen
MTU probe can cause some remedies for FRTO because the normal packet ordering may be violated allowing FRTO to make a wrong decision (it might not be that serious threat for anything though). Thus it's safer to not run FRTO while MTU probe is underway. It seems that the basic FRTO variant should also look for an skb at probe_seq.start to check if that's retransmitted one but I didn't implement it now (plain seqno in window check isn't robust against wraparounds). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-07[TCP]: tcp_simple_retransmit can cause S+LIlpo Järvinen
This fixes Bugzilla #10384 tcp_simple_retransmit does L increment without any checking whatsoever for overflowing S+L when Reno is in use. The simplest scenario I can currently think of is rather complex in practice (there might be some more straightforward cases though). Ie., if mss is reduced during mtu probing, it may end up marking everything lost and if some duplicate ACKs arrived prior to that sacked_out will be non-zero as well, leading to S+L > packets_out, tcp_clean_rtx_queue on the next cumulative ACK or tcp_fastretrans_alert on the next duplicate ACK will fix the S counter. More straightforward (but questionable) solution would be to just call tcp_reset_reno_sack() in tcp_simple_retransmit but it would negatively impact the probe's retransmission, ie., the retransmissions would not occur if some duplicate ACKs had arrived. So I had to add reno sacked_out reseting to CA_Loss state when the first cumulative ACK arrives (this stale sacked_out might actually be the explanation for the reports of left_out overflows in kernel prior to 2.6.23 and S+L overflow reports of 2.6.24). However, this alone won't be enough to fix kernel before 2.6.24 because it is building on top of the commit 1b6d427bb7e ([TCP]: Reduce sacked_out with reno when purging write_queue) to keep the sacked_out from overflowing. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Reported-by: Alessandro Suardi <alessandro.suardi@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-07[TCP]: Fix NewReno's fast rexmit/recovery problems with GSOed skbIlpo Järvinen
Fixes a long-standing bug which makes NewReno recovery crippled. With GSO the whole head skb was marked as LOST which is in violation of NewReno procedure that only wants to mark one packet and ended up breaking our TCP code by causing counter overflow because our code was built on top of assumption about valid NewReno procedure. This manifested as triggering a WARN_ON for the overflow in a number of places. It seems relatively safe alternative to just do nothing if tcp_fragment fails due to oom because another duplicate ACK is likely to be received soon and the fragmentation will be retried. Special thanks goes to Soeren Sonnenburg <kernel@nn7.de> who was lucky enough to be able to reproduce this so that the warning for the overflow was hit. It's not as easy task as it seems even if this bug happens quite often because the amount of outstanding data is pretty significant for the mismarkings to lead to an overflow. Because it's very late in 2.6.25-rc cycle (if this even makes in time), I didn't want to touch anything with SACK enabled here. Fragmenting might be useful for it as well but it's more or less a policy decision rather than mandatory fix. Thus there's no need to rush and we can postpone considering tcp_fragment with SACK for 2.6.26. In 2.6.24 and earlier, this very same bug existed but the effect is slightly different because of a small changes in the if conditions that fit to the patch's context. With them nothing got lost marker and thus no retransmissions happened. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-07[TCP]: Restore 2.6.24 mark_head_lost behavior for newreno/fackIlpo Järvinen
The fast retransmission can be forced locally to the rfc3517 branch in tcp_update_scoreboard instead of making such fragile constructs deeper in tcp_mark_head_lost. This is necessary for the next patch which must not have loopholes for cnt > packets check. As one can notice, readability got some improvements too because of this :-). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-21[TCP]: TCP_DEFER_ACCEPT updates - process as establishedPatrick McManus
Change TCP_DEFER_ACCEPT implementation so that it transitions a connection to ESTABLISHED after handshake is complete instead of leaving it in SYN-RECV until some data arrvies. Place connection in accept queue when first data packet arrives from slow path. Benefits: - established connection is now reset if it never makes it to the accept queue - diagnostic state of established matches with the packet traces showing completed handshake - TCP_DEFER_ACCEPT timeouts are expressed in seconds and can now be enforced with reasonable accuracy instead of rounding up to next exponential back-off of syn-ack retry. Signed-off-by: Patrick McManus <mcmanus@ducksong.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-05net: replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-05Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: net/mac80211/rc80211_pid_algo.c
2008-03-04[TCP]: Add IPv6 support to TCP SYN cookiesGlenn Griffin
Updated to incorporate Eric's suggestion of using a per cpu buffer rather than allocating on the stack. Just a two line change, but will resend in it's entirety. Signed-off-by: Glenn Griffin <ggriffin.kernel@gmail.com> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-03-03[TCP]: Must count fack_count also when skippingIlpo Järvinen
It makes fackets_out to grow too slowly compared with the real write queue. This shouldn't cause those BUG_TRAP(packets <= tp->packets_out) to trigger but how knows how such inconsistent fackets_out affects here and there around TCP when everything is nowadays assuming accurate fackets_out. So lets see if this silences them all. Reported by Guillaume Chazarain <guichaz@gmail.com>. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-31[TCP]: NewReno must count every skb while marking lossesIlpo Järvinen
NewReno should add cnt per skb (as with FACK) instead of depending on SACKED_ACKED bits which won't be set with it at all. Effectively, NewReno should always exists after the first iteration anyway (or immediately if there's already head in lost_out. This was fixed earlier in net-2.6.25 but got reverted among other stuff and I didn't notice that this is still necessary (actually wasn't even considering this case while trying to figure out the reports because I lived with different kind of code than it in reality was). This should solve the WARN_ONs in TCP code that as a result of this triggered multiple times in every place we check for this invariant. Special thanks to Dave Young <hidave.darkstar@gmail.com> and Krishna Kumar2 <krkumar2@in.ibm.com> for trying with my debug patches. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Tested-by: Dave Young <hidave.darkstar@gmail.com> Tested-by: Krishna Kumar2 <krkumar2@in.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: cleanup tcp_parse_options deep indented switchIlpo Järvinen
Removed case indentation level & combined some nested ifs, mostly within 80 lines now. This is a leftover from indent patch, it just had to be done manually to avoid messing it up completely. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: cleanup tcp_{in,out}put.c styleIlpo Järvinen
These were manually selected from indent's results which as is are too noisy to be of any use without human reason. In addition, some extra newlines between function and its comment were removed too. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Remove TCPCB_URG & TCPCB_AT_TAIL as unnecessaryIlpo Järvinen
The snd_up check should be enough. I suspect this has been there to provide a minor optimization in clean_rtx_queue which used to have a small if (!->sacked) block which could skip snd_up check among the other work. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Dropped unnecessary skb/sacked accessing in renegingIlpo Järvinen
SACK reneging can be precalculated to a FLAG in clean_rtx_queue which has the right skb looked up. This will help a bit in future because skb->sacked access will be changed eventually, changing it already won't hurt any. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Introduce tcp_wnd_end() to reduce line lengthsIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Make invariant check complain about invalid sacked_outIlpo Järvinen
Earlier resolution for NewReno's sacked_out should now keep it small enough for this to become invariant-like check. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET] CORE: Introducing new memory accounting interface.Hideo Aoki
This patch introduces new memory accounting functions for each network protocol. Most of them are renamed from memory accounting functions for stream protocols. At the same time, some stream memory accounting functions are removed since other functions do same thing. Renaming: sk_stream_free_skb() -> sk_wmem_free_skb() __sk_stream_mem_reclaim() -> __sk_mem_reclaim() sk_stream_mem_reclaim() -> sk_mem_reclaim() sk_stream_mem_schedule -> __sk_mem_schedule() sk_stream_pages() -> sk_mem_pages() sk_stream_rmem_schedule() -> sk_rmem_schedule() sk_stream_wmem_schedule() -> sk_wmem_schedule() sk_charge_skb() -> sk_mem_charge() Removeing sk_stream_rfree(): consolidates into sock_rfree() sk_stream_set_owner_r(): consolidates into skb_set_owner_r() sk_stream_mem_schedule() The following functions are added. sk_has_account(): check if the protocol supports accounting sk_mem_uncharge(): do the opposite of sk_mem_charge() In addition, to achieve consolidation, updating sk_wmem_queued is removed from sk_mem_charge(). Next, to consolidate memory accounting functions, this patch adds memory accounting calls to network core functions. Moreover, present memory accounting call is renamed to new accounting call. Finally we replace present memory accounting calls with new interface in TCP and SCTP. Signed-off-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Hideo Aoki <haoki@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Remove seq_rtt ptr from clean_rtx_queue argsIlpo Järvinen
While checking Gavin's patch I noticed that the returned seq_rtt is not used by the caller. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Avoid two divides in __tcp_grow_window()Eric Dumazet
tcp_win_from_space() being signed, compiler might emit an integer divide to compute tcp_win_from_space()/2 . Using right shifts is OK here and less expensive. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Abstract tp->highest_sack accessing & point to next skbIlpo Järvinen
Pointing to the next skb is necessary to avoid referencing already SACKed skbs which will soon be on a separate list. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Cleanup local variables of clean_rtx_queueIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Add unlikely() to urgent handling in clean_rtx_queueIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Remove duplicated code block from clean_rtx_queueIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoidIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Unite identical code from two seqno split blocksIlpo Järvinen
Bogus seqno compares just mislead, the code is identical for both sides of the seqno compare (and was even executed just once because of return in between). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Remove superflucious FLAG_DATA_SACKEDIlpo Järvinen
To get there, highest_sack must have advanced. When it advances, a new skb is SACKed, which already sets that FLAG. Besides, the original purpose of it has puzzled me, never understood why LOST bit setting of retransmitted skb is marked with FLAG_DATA_SACKED. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Move LOSTRETRANS MIB outside !(L|S) checkIlpo Järvinen
Usually those skbs will have L set, not counting them as lost retransmissions is misleading. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Two fixes to new sacktag codeIlpo Järvinen
1) Skip condition used to be wrong way around which made SACK processing very broken, missed many blocks because of that. 2) Use highest_sack advancement only if some skbs are already sacked because otherwise tcp_write_queue_next may move things too far (occurs mainly with GSO). The other similar advancement is not problem because highest_sack was previosly put to point a sacked skb. These problems were located because of problem report from Matt Mathis <mathis@psc.edu>. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Name magic constants in sock_wake_async()Pavel Emelyanov
The sock_wake_async() performs a bit different actions depending on "how" argument. Unfortunately this argument ony has numerical magic values. I propose to give names to their constants to help people reading this function callers understand what's going on without looking into this function all the time. I suppose this is 2.6.25 material, but if it's not (or the naming seems poor/bad/awful), I can rework it against the current net-2.6 tree. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Correct DSACK check placingIlpo Järvinen
Previously one of the in-block skip branches was missing it. Also, drop it from tail-fully-processed case because the next iteration will do exactly the same thing, i.e., process the SACK block that contains the DSACK information. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Rewrite SACK block processing & sack_recv_cache useIlpo Järvinen
Key points of this patch are: - In case new SACK information is advance only type, no skb processing below previously discovered highest point is done - Optimize cases below highest point too since there's no need to always go up to highest point (which is very likely still present in that SACK), this is not entirely true though because I'm dropping the fastpath_skb_hint which could previously optimize those cases even better. Whether that's significant, I'm not too sure. Currently it will provide skipping by walking. Combined with RB-tree, all skipping would become fast too regardless of window size (can be done incrementally later). Previously a number of cases in TCP SACK processing fails to take advantage of costly stored information in sack_recv_cache, most importantly, expected events such as cumulative ACK and new hole ACKs. Processing on such ACKs result in rather long walks building up latencies (which easily gets nasty when window is huge). Those latencies are often completely unnecessary compared with the amount of _new_ information received, usually for cumulative ACK there's no new information at all, yet TCP walks whole queue unnecessary potentially taking a number of costly cache misses on the way, etc.! Since the inclusion of highest_sack, there's a lot information that is very likely redundant (SACK fastpath hint stuff, fackets_out, highest_sack), though there's no ultimate guarantee that they'll remain the same whole the time (in all unearthly scenarios). Take advantage of this knowledge here and drop fastpath hint and use direct access to highest SACKed skb as a replacement. Effectively "special cased" fastpath is dropped. This change adds some complexity to introduce better coveraged "fastpath", though the added complexity should make TCP behave more cache friendly. The current ACK's SACK blocks are compared against each cached block individially and only ranges that are new are then scanned by the high constant walk. For other parts of write queue, even when in previously known part of the SACK blocks, a faster skip function is used (if necessary at all). In addition, whenever possible, TCP fast-forwards to highest_sack skb that was made available by an earlier patch. In typical case, no other things but this fast-forward and mandatory markings after that occur making the access pattern quite similar to the former fastpath "special case". DSACKs are special case that must always be walked. The local to recv_sack_cache copying could be more intelligent w.r.t DSACKs which are likely to be there only once but that is left to a separate patch. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Earlier SACK block verification & simplify access to themIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Create tcp_sacktag_one().Ilpo Järvinen
Worker function that implements the main logic of the inner-most loop of tcp_sacktag_write_queue(). Idea was originally presented by David S. Miller. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Prior_fackets can be replaced by highest_sack seqIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Make lost retrans detection more self-containedIlpo Järvinen
Highest_sack_end_seq is no longer calculated in the loop, thus it can be pushed to the worker function altogether making that function independent of the sacktag. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Convert highest_sack to sk_buff to allow direct accessIlpo Järvinen
It is going to replace the sack fastpath hint quite soon... :-) Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: non-FACK SACK follows conservative SACK loss recoveryIlpo Järvinen
Many assumptions that are true when no reordering or other strange events happen are not a part of the RFC3517. FACK implementation is based on such assumptions. Previously (before the rewrite) the non-FACK SACK was basically doing fast rexmit and then it times out all skbs when first cumulative ACK arrives, which cannot really be called SACK based recovery :-). RFC3517 SACK disables these things: - Per SKB timeouts & head timeout entry to recovery - Marking at least one skb while in recovery (RFC3517 does this only for the fast retransmission but not for the other skbs when cumulative ACKs arrive in the recovery) - Sacktag's loss detection flavors B and C (see comment before tcp_sacktag_write_queue) This does not implement the "last resort" rule 3 of NextSeg, which allows retransmissions also when not enough SACK blocks have yet arrived above a segment for IsLost to return true [RFC3517]. The implementation differs from RFC3517 in these points: - Rate-halving is used instead of FlightSize / 2 - Instead of using dupACKs to trigger the recovery, the number of SACK blocks is used as FACK does with SACK blocks+holes (which provides more accurate number). It seems that the difference can affect negatively only if the receiver does not generate SACK blocks at all even though it claimed to be SACK-capable. - Dupthresh is not a constant one. Dynamical adjustments include both holes and sacked segments (equal to what FACK has) due to complexity involved in determining the number sacked blocks between highest_sack and the reordered segment. Thus it's will be an over-estimate. Implementation note: tcp_clean_rtx_queue doesn't need a lost_cnt tweak because head skb at that point cannot be SACKED_ACKED (nor would such situation last for long enough to cause problems). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Extend reordering detection to cover CA_Loss partiallyIlpo Järvinen
This implements more accurately what is stated in sacktag's overall comment: "Both of these heuristics are not used in Loss state, when we cannot account for retransmits accurately." When CA_Loss state is entered, the state changer ensures that undo_marker is only set if no TCPCB_RETRANS skbs were found, thus having non-zero undo_marker in CA_Loss basically tells that the R-bits still accurately reflect the current state of TCP. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Move !in_sack test earlier in sacktag & reorganize if()sIlpo Järvinen
All intermediate conditions include it already, make them simpler as well. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-29[TCP]: use non-delayed ACK for congestion control RTTGavin McCullagh
When a delayed ACK representing two packets arrives, there are two RTT samples available, one for each packet. The first (in order of seq number) will be artificially long due to the delay waiting for the second packet, the second will trigger the ACK and so will not itself be delayed. According to rfc1323, the SRTT used for RTO calculation should use the first rtt, so receivers echo the timestamp from the first packet in the delayed ack. For congestion control however, it seems measuring delayed ack delay is not desirable as it varies independently of congestion. The patch below causes seq_rtt and last_ackt to be updated with any available later packet rtts which should have less (and hopefully zero) delack delay. The rtt value then gets passed to ca_ops->pkts_acked(). Where TCP_CONG_RTT_STAMP was set, effort was made to supress RTTs from within a TSO chunk (!fully_acked), using only the final ACK (which includes any TSO delay) to generate RTTs. This patch removes these checks so RTTs are passed for each ACK to ca_ops->pkts_acked(). For non-delay based congestion control (cubic, h-tcp), rtt is sometimes used for rtt-scaling. In shortening the RTT, this may make them a little less aggressive. Delay-based schemes (eg vegas, veno, illinois) should get a cleaner, more accurate congestion signal, particularly for small cwnds. The congestion control module can potentially also filter out bad RTTs due to the delayed ack alarm by looking at the associated cnt which (where delayed acking is in use) should probably be 1 if the alarm went off or greater if the ACK was triggered by a packet. Signed-off-by: Gavin McCullagh <gavin.mccullagh@nuim.ie> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-16[IPV4]: Make tcp_input_metrics() get minimum RTO via tcp_rto_min()Satoru SATOH
tcp_input_metrics() refers to the built-time constant TCP_RTO_MIN regardless of configured minimum RTO with iproute2. Signed-off-by: Satoru SATOH <satoru.satoh@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-05[TCP]: Move prior_in_flight collect to more robust placeIlpo Järvinen
The previous location is after sacktag processing, which affects counters tcp_packets_in_flight depends on. This may manifest as wrong behavior if new SACK blocks are present and all is clear for call to tcp_cong_avoid, which in the case of tcp_reno_cong_avoid bails out early because it thinks that TCP is not limited by cwnd. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>