summaryrefslogtreecommitdiffstats
path: root/net/ipv4/tcp_input.c
Commit message (Collapse)AuthorAgeFilesLines
* [TCP]: NewReno must count every skb while marking lossesIlpo Järvinen2008-02-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [TCP]: cleanup tcp_parse_options deep indented switchIlpo Järvinen2008-01-291-68/+67Star
| | | | | | | | | 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>
* [TCP]: cleanup tcp_{in,out}put.c styleIlpo Järvinen2008-01-291-209/+227
| | | | | | | | | | 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>
* [TCP]: Remove TCPCB_URG & TCPCB_AT_TAIL as unnecessaryIlpo Järvinen2008-01-291-2/+1Star
| | | | | | | | | | 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>
* [TCP]: Dropped unnecessary skb/sacked accessing in renegingIlpo Järvinen2008-01-291-12/+13
| | | | | | | | | | 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>
* [TCP]: Introduce tcp_wnd_end() to reduce line lengthsIlpo Järvinen2008-01-291-2/+1Star
| | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Make invariant check complain about invalid sacked_outIlpo Järvinen2008-01-291-4/+1Star
| | | | | | | | 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>
* [NET] CORE: Introducing new memory accounting interface.Hideo Aoki2008-01-291-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [TCP]: Remove seq_rtt ptr from clean_rtx_queue argsIlpo Järvinen2008-01-291-5/+2Star
| | | | | | | | 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>
* [TCP]: Avoid two divides in __tcp_grow_window()Eric Dumazet2008-01-291-2/+2
| | | | | | | | | | 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>
* [TCP]: Abstract tp->highest_sack accessing & point to next skbIlpo Järvinen2008-01-281-12/+15
| | | | | | | | | 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>
* [TCP]: Cleanup local variables of clean_rtx_queueIlpo Järvinen2008-01-281-14/+12Star
| | | | | | 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>
* [TCP]: Add unlikely() to urgent handling in clean_rtx_queueIlpo Järvinen2008-01-281-2/+2
| | | | | | 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>
* [TCP]: Remove duplicated code block from clean_rtx_queueIlpo Järvinen2008-01-281-29/+21Star
| | | | | | 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>
* [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoidIlpo Järvinen2008-01-281-5/+4Star
| | | | | | 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>
* [TCP]: Unite identical code from two seqno split blocksIlpo Järvinen2008-01-281-6/+1Star
| | | | | | | | | | 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>
* [TCP]: Remove superflucious FLAG_DATA_SACKEDIlpo Järvinen2008-01-281-7/+3Star
| | | | | | | | | | | | 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>
* [TCP]: Move LOSTRETRANS MIB outside !(L|S) checkIlpo Järvinen2008-01-281-1/+1
| | | | | | | | | 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>
* [TCP]: Two fixes to new sacktag codeIlpo Järvinen2008-01-281-2/+2
| | | | | | | | | | | | | | | | | | 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>
* [NET]: Name magic constants in sock_wake_async()Pavel Emelyanov2008-01-281-6/+6
| | | | | | | | | | | | | | | | | | 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>
* [TCP]: Correct DSACK check placingIlpo Järvinen2008-01-281-10/+5Star
| | | | | | | | | | | 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>
* [TCP]: Rewrite SACK block processing & sack_recv_cache useIlpo Järvinen2008-01-281-100/+171
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [TCP]: Earlier SACK block verification & simplify access to themIlpo Järvinen2008-01-281-34/+51
| | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Create tcp_sacktag_one().Ilpo Järvinen2008-01-281-96/+96
| | | | | | | | | | 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>
* [TCP]: Prior_fackets can be replaced by highest_sack seqIlpo Järvinen2008-01-281-3/+2Star
| | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Make lost retrans detection more self-containedIlpo Järvinen2008-01-281-9/+11
| | | | | | | | | 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>
* [TCP]: Convert highest_sack to sk_buff to allow direct accessIlpo Järvinen2008-01-281-6/+6
| | | | | | | 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>
* [TCP]: non-FACK SACK follows conservative SACK loss recoveryIlpo Järvinen2008-01-281-18/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [TCP]: Extend reordering detection to cover CA_Loss partiallyIlpo Järvinen2008-01-281-1/+2
| | | | | | | | | | | | | | | | | 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>
* [TCP]: Move !in_sack test earlier in sacktag & reorganize if()sIlpo Järvinen2008-01-281-17/+14Star
| | | | | | | | 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>
* [TCP]: use non-delayed ACK for congestion control RTTGavin McCullagh2007-12-301-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [IPV4]: Make tcp_input_metrics() get minimum RTO via tcp_rto_min()Satoru SATOH2007-12-161-1/+1
| | | | | | | | 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>
* [TCP]: Move prior_in_flight collect to more robust placeIlpo Järvinen2007-12-051-2/+1Star
| | | | | | | | | | | | 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>
* [TCP] FRTO: Use of existing funcs make code more obvious & robustIlpo Järvinen2007-12-051-9/+5Star
| | | | | | | | | | | | | | | | | | | | Though there's little need for everything that tcp_may_send_now does (actually, even the state had to be adjusted to pass some checks FRTO does not want to occur), it's more robust to let it make the decision if sending is allowed. State adjustments needed: - Make sure snd_cwnd limit is not hit in there - Disable nagle (if necessary) through the frto_counter == 2 The result of check for frto_counter in argument to call for tcp_enter_frto_loss can just be open coded, therefore there isn't need to store the previous frto_counter past tcp_may_send_now. In addition, returns can then be combined. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP] FRTO: Clear frto_highmark only after process_frto that uses itIlpo Järvinen2007-11-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | I broke this in commit 3de96471bd7fb76406e975ef6387abe3a0698149: [TCP]: Wrap-safed reordering detection FRTO check tcp_process_frto should always see a valid frto_highmark. An invalid frto_highmark (zero) is very likely what ultimately caused a seqno compare in tcp_frto_enter_loss to do the wrong leading to the LOST-bit leak. Having LOST-bits integry ensured like done after commit 23aeeec365dcf8bc87fae44c533e50d0bb4f23cc: [TCP] FRTO: Plug potential LOST-bit leak won't hurt. It may still be useful in some other, possibly legimate, scenario. Reported by Chazarain Guillaume <guichaz@yahoo.fr>. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Make sure write_queue_from does not begin with NULL ptrIlpo Järvinen2007-11-151-0/+5
| | | | | | | | | | | | | | NULL ptr can be returned from tcp_write_queue_head to cached_skb and then assigned to skb if packets_out was zero. Without this, system is vulnerable to a carefully crafted ACKs which obviously is remotely triggerable. Besides, there's very little that needs to be done in sacktag if there weren't any packets outstanding, just skipping the rest doesn't hurt. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP] FRTO: Plug potential LOST-bit leakIlpo Järvinen2007-11-141-1/+3
| | | | | | | | | | | | | | It might be possible that, in some extreme scenario that I just cannot now construct in my mind, end_seq <= frto_highmark check does not match causing the lost_out and LOST bits become out-of-sync due to clearing and recounting in the loop. This may fix LOST-bit leak reported by Chazarain Guillaume <guichaz@yahoo.fr>. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP] FRTO: Limit snd_cwnd if TCP was application limitedIlpo Järvinen2007-11-141-0/+3
| | | | | | | | | | | | | | | | | | Otherwise TCP might violate packet ordering principles that FRTO is based on. If conventional recovery path is chosen, this won't be significant at all. In practice, any small enough value will be sufficient to provide proper operation for FRTO, yet other users of snd_cwnd might benefit from a "close enough" value. FRTO's formula is now equal to what tcp_enter_cwr() uses. FRTO used to check application limitedness a bit differently but I changed that in commit 575ee7140dabe9b9c4f66f4f867039b97e548867 and as a result checking for application limitedness became completely non-existing. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Split SACK FRTO flag clearing (fixes FRTO corner case bug)Ilpo Järvinen2007-11-111-18/+17Star
| | | | | | | | | | | | | | | | | In case we run out of mem when fragmenting, the clearing of FLAG_ONLY_ORIG_SACKED might get missed which then feeds FRTO with false information. Move clearing outside skb processing loop so that it will get executed even if the skb loop terminates prematurely due to out-of-mem. Besides, now the core of the loop truly deals with a single skb only, which also enables creation a more self-contained of tcp_sacktag_one later on. In addition, small reorganization of if branches was made. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Add unlikely() to sacktag out-of-mem in fragment caseIlpo Järvinen2007-11-111-1/+1
| | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Fix reord detection due to snd_una covered holesIlpo Järvinen2007-11-111-18/+32
| | | | | | | | | | | | | | | | | | | Fixes subtle bug like the one with fastpath_cnt_hint happening due to the way the GSO and hints interact. Because hints are not reset when just a GSOed skb is partially ACKed, there's no guarantee that the relevant part of the write queue is going to be processed in sacktag at all (skbs below snd_una) because fastpath hint can fast forward the entrypoint. This was also on the way of future reductions in sacktag's skb processing. Also future cleanups in sacktag can be made after this (in 2.6.25). This may make reordering update in tcp_try_undo_partial redundant but I'm not too sure so I left it there. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Consider GSO while counting reord in sacktagIlpo Järvinen2007-11-111-4/+8
| | | | | | | | | | Reordering detection fails to take account that the reordered skb may have pcount larger than 1. In such case the lowest of them had the largest reordering, the old formula used the highest of them which is pcount - 1 packets less reordered. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Another TAGBITS -> SACKED_ACKED|LOST conversionIlpo Järvinen2007-11-011-1/+1
| | | | | | | | Similar to commit 3eec0047d9bdd, point of this is to avoid skipping R-bit skbs. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Process DSACKs that reside within a SACK blockIlpo Järvinen2007-11-011-3/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DSACK inside another SACK block were missed if start_seq of DSACK was larger than SACK block's because sorting prioritizes full processing of the SACK block before DSACK. After SACK block sorting situation is like this: SSSSSSSSS D SSSSSS SSSSSSS Because write_queue is walked in-order, when the first SACK block has been processed, TCP is already past the skb for which the DSACK arrived and we haven't taught it to backtrack (nor should we), so TCP just continues processing by going to the next SACK block after the DSACK (if any). Whenever such DSACK is present, do an embedded checking during the previous SACK block. If the DSACK is below snd_una, there won't be overlapping SACK block, and thus no problem in that case. Also if start_seq of the DSACK is equal to the actual block, it will be processed first. Tested this by using netem to duplicate 15% of packets, and by printing SACK block when found_dup_sack is true and the selected skb in the dup_sack = 1 branch (if taken): SACK block 0: 4344-5792 (relative to snd_una 2019137317) SACK block 1: 4344-5792 (relative to snd_una 2019137317) equal start seqnos => next_dup = 0, dup_sack = 1 won't occur... SACK block 0: 5792-7240 (relative to snd_una 2019214061) SACK block 1: 2896-7240 (relative to snd_una 2019214061) DSACK skb match 5792-7240 (relative to snd_una) ...and next_dup = 1 case (after the not shown start_seq sort), went to dup_sack = 1 branch. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: fix D-SACK cwnd handlingRyousei Takano2007-10-261-7/+5Star
| | | | | | | | | | | | | | | | | In the current net-2.6 kernel, handling FLAG_DSACKING_ACK is broken. The flag is cleared to 1 just after FLAG_DSACKING_ACK is set. if (found_dup_sack) flag |= FLAG_DSACKING_ACK; : flag = 1; To fix it, this patch introduces a part of the tcp_sacktag_state patch: http://marc.info/?l=linux-netdev&m=119210560431519&w=2 Signed-off-by: Ryousei Takano <takano-ryousei@aist.go.jp> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Make tcp_match_skb_to_sack() static.Adrian Bunk2007-10-261-2/+2
| | | | | | | tcp_match_skb_to_sack() can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Fix inconsistency of terms.Ryousei Takano2007-10-261-8/+8
| | | | | | | | | Fix inconsistency of terms: 1) D-SACK 2) F-RTO Signed-off-by: Ryousei Takano <takano-ryousei@aist.go.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Treat the sign of the result of skb_headroom() consistentlyChuck Lever2007-10-241-1/+1
| | | | | | | | | In some places, the result of skb_headroom() is compared to an unsigned integer, and in others, the result is compared to a signed integer. Make the comparisons consistent and correct. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Remove lost_retrans zero seqno special casesIlpo Järvinen2007-10-181-3/+3
| | | | | | | | | | | | | | | | Both high-sack detection and new lowest seq variables have unnecessary zero special case which are now removed by setting safe initial seqnos. This also fixes problem which caused zero received_upto being passed to tcp_mark_lost_retrans which confused after relations within the marker loop causing incorrect TCPCB_SACKED_RETRANS clearing. The problem was noticed because of a performance report from TAKANO Ryousei <takano@axe-inc.co.jp>. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Ryousei Takano <takano-ryousei@aist.go.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: high_seq parameter removed (all callers use tp->high_seq)Ilpo Järvinen2007-10-151-6/+5Star
| | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-20 21:01:47 +0200