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* [PATCH] slab: remove SLAB_ATOMICChristoph Lameter2006-12-072-4/+4
| | | | | | | | SLAB_ATOMIC is an alias of GFP_ATOMIC Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [DCCP] tfrc: Binary search for reverse TFRC lookupGerrit Renker2006-12-031-14/+24
| | | | | | | | | | | | | This replaces the linear search algorithm for reverse lookup with binary search. It has the advantage of better scalability: O(log2(N)) instead of O(N). This means that the average number of iterations is reduced from 250 (linear search if each value appears equally likely) down to at most 9. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Deprecate TFRC_SMALLEST_PGerrit Renker2006-12-032-18/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch deprecates the existing use of an arbitrary value TFRC_SMALLEST_P for low-threshold values of p. This avoids masking low-resolution errors. Instead, the code now checks against real boundaries (implemented by preceding patch) and provides warnings whenever a real value falls below the threshold. If such messages are observed, it is a better solution to take this as an indication that the lookup table needs to be re-engineered. Changelog: ---------- This patch * makes handling all TFRC resolution errors local to the TFRC library * removes unnecessary test whether X_calc is 'infinity' due to p==0 -- this condition is already caught by tfrc_calc_x() * removes setting ccid3hctx_p = TFRC_SMALLEST_P in ccid3_hc_tx_packet_recv since this is now done by the TFRC library * updates BUG_ON test in ccid3_hc_tx_no_feedback_timer to take into account that p now is either 0 (and then X_calc is irrelevant), or it is > 0; since the handling of TFRC_SMALLEST_P is now taken care of in the tfrc library Justification: -------------- The TFRC code uses a lookup table which has a bounded resolution. The lowest possible value of the loss event rate `p' which can be resolved is currently 0.0001. Substituting this lower threshold for p when p is less than 0.0001 results in a huge, exponentially-growing error. The error can be computed by the following formula: (f(0.0001) - f(p))/f(p) * 100 for p < 0.0001 Currently the solution is to use an (arbitrary) value TFRC_SMALLEST_P = 40 * 1E-6 = 0.00004 and to consider all values below this value as `virtually zero'. Due to the exponentially growing resolution error, this is not a good idea, since it hides the fact that the table can not resolve practically occurring cases. Already at p == TFRC_SMALLEST_P, the error is as high as 58.19%! Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] tfrc: Identify TFRC table limits and simplify codeGerrit Renker2006-12-031-9/+18
| | | | | | | | | | | | | | | | This * adds documentation about the lowest resolution that is possible within the bounds of the current lookup table * defines a constant TFRC_SMALLEST_P which defines this resolution * issues a warning if a given value of p is below resolution * combines two previously adjacent if-blocks of nearly identical structure into one This patch does not change the algorithm as such. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] tfrc: Add protection against invalid parameters to TFRC routinesGerrit Renker2006-12-031-14/+19
| | | | | | | | | | | | | | | | | | | | | 1) For the forward X_calc lookup, it * protects effectively against RTT=0 (this case is possible), by returning the maximal lookup value instead of just setting it to 1 * reformulates the array-bounds exceeded condition: this only happens if p is greater than 1E6 (due to the scaling) * the case of negative indices can now with certainty be excluded, since documentation shows that the formulas are within bounds * additional protection against p = 0 (would give divide-by-zero) 2) For the reverse lookup, it warns against * protects against exceeding array bounds * now returns 0 if f(p) = 0, due to function definition * warns about minimal resolution error and returns the smallest table value instead of p=0 [this would mask congestion conditions] Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] tfrc: Fix small error in reverse lookup of p for given f(p)Gerrit Renker2006-12-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes the following small error in tfrc_calc_x_reverse_lookup. 1) The table is generated by the following equations: lookup[index][0] = g((index+1) * 1000000/TFRC_CALC_X_ARRSIZE); lookup[index][1] = g((index+1) * TFRC_CALC_X_SPLIT/TFRC_CALC_X_ARRSIZE); where g(q) is 1E6 * f(q/1E6) 2) The reverse lookup assigns an entry in lookup[index][small] 3) This index needs to match the above, i.e. * if small=0 then p = (index + 1) * 1000000/TFRC_CALC_X_ARRSIZE * if small=1 then p = (index+1) * TFRC_CALC_X_SPLIT/TFRC_CALC_X_ARRSIZE These are exactly the changes that the patch makes; previously the code did not conform to the way the lookup table was generated (this difference resulted in a mean error of about 1.12%). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] tfrc: Document boundaries and limits of the TFRC lookup tableGerrit Renker2006-12-031-56/+88
| | | | | | | | | | | | | | | This adds documentation for the TCP Reno throughput equation which is at the heart of the TFRC sending rate / loss rate calculations. It spells out precisely how the values were determined and what they mean. The equations were derived through reverse engineering and found to be fully accurate (verified using test programs). This patch does not change any code. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Fix warning message about illegal ACKGerrit Renker2006-12-031-1/+2
| | | | | | | | | | | | | | | | | | | | This avoids a (harmless) warning message being printed at the DCCP server (the receiver of a DCCP half connection). Incoming packets are both directed to * ccid_hc_rx_packet_recv() for the server half * ccid_hc_tx_packet_recv() for the client half The message gets printed since on a server the client half is currently not sending data packets. This is resolved for the moment by checking the DCCP-role first. In future times (bidirectional DCCP connections), this test may have to be more sophisticated. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Fix bug in calculation of send rateGerrit Renker2006-12-031-37/+52
| | | | | | | | | | | | | | | | | | | The main object of this patch is the following bug: ==> In ccid3_hc_tx_packet_recv, the parameters p and X_recv were updated _after_ the send rate was calculated. This is clearly an error and is resolved by re-ordering statements. In addition, * r_sample is converted from u32 to long to check whether the time difference was negative (it would otherwise be converted to a large u32 value) * protection against RTT=0 (this is possible) is provided in a further patch * t_elapsed is also converted to long, to match the type of r_sample * adds a a more debugging information regarding current send rates * various trivial comment/documentation updates Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: Fix BUG in retransmission delay calculationGerrit Renker2006-12-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | This bug resulted in ccid3_hc_tx_send_packet returning negative delay values, which in turn triggered silently dequeueing packets in dccp_write_xmit. As a result, only a few out of the submitted packets made it at all onto the network. Occasionally, when dccp_wait_for_ccid was involved, this also triggered a bug warning since ccid3_hc_tx_send_packet returned a negative value (which in reality was a negative delay value). The cause for this bug lies in the comparison if (delay >= hctx->ccid3hctx_delta) return delay / 1000L; The type of `delay' is `long', that of ccid3hctx_delta is `u32'. When comparing negative long values against u32 values, the test returned `true' whenever delay was smaller than 0 (meaning the packet was overdue to send). The fix is by casting, subtracting, and then testing the difference with regard to 0. This has been tested and shown to work. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: Use higher RTO default for CCID3Gerrit Renker2006-12-032-8/+46
| | | | | | | | | | | | | | | | | The TFRC nofeedback timer normally expires after the maximum of 4 RTTs and twice the current send interval (RFC 3448, 4.3). On LANs with a small RTT this can mean a high processing load and reduced performance, since then the nofeedback timer is triggered very frequently. This patch provides a configuration option to set the bound for the nofeedback timer, using as default 100 milliseconds. By setting the configuration option to 0, strict RFC 3448 behaviour can be enforced for the nofeedback timer. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: Use `unsigned' for packet lengthsGerrit Renker2006-12-022-48/+40
| | | | | | | | | | | | | | | | | | | | | | This patch implements a suggestion by Ian McDonald and 1) Avoids tests against negative packet lengths by using unsigned int for packet payload lengths in the CCID send_packet()/packet_sent() routines 2) As a consequence, it removes an now unnecessary test with regard to `len > 0' in ccid3_hc_tx_packet_sent: that condition is always true, since * negative packet lengths are avoided * ccid3_hc_tx_send_packet flags an error whenever the payload length is 0. As a consequence, ccid3_hc_tx_packet_sent is never called as all errors returned by ccid_hc_tx_send_packet are caught in dccp_write_xmit 3) Removes the third argument of ccid_hc_tx_send_packet (the `len' parameter), since it is currently always set to skb->len. The code is updated with regard to this parameter change. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Larger initial windowsGerrit Renker2006-12-022-33/+37
| | | | | | | | | | | | | | | | | | | | | | This implements the larger-initial-windows feature for CCID 3, as described in section 5 of RFC 4342. When the first feedback packet arrives, the sender can send up to 2..4 packets per RTT, instead of just one. The patch further * reduces the number of timestamping calls by passing the timestamp value (which is computed in one of the calling functions anyway) as argument * renames one constant with a very long name into one which is shorter and resembles the one in RFC 3448 (t_mbi) * simplifies some of the min_t/max_t cases where both `x', `y' have the same type Commiter note: renamed TFRC_t_mbi to TFRC_T_MBI, to follow Linux coding style. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: Tidy up unused structuresGerrit Renker2006-12-021-4/+0
| | | | | | | | | | | | | This removes and cleans up unused variables and structures which have become unnecessary following the introduction of the EWMA patch to automatically track the CCID 3 receiver/sender packet sizes `s'. It deprecates the PACKET_SIZE socket option by returning an error code and printing a deprecation warning if an application tries to read or write this socket option. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Track RX/TX packet size `s' using moving-averageGerrit Renker2006-12-021-19/+41
| | | | Problem:
* [DCCP] ccid3: Set NoFeedback Timeout according to RFC 3448Gerrit Renker2006-12-021-12/+10
| | | | | | | | | | | This corrects the setting of the nofeedback timer with regard to RFC 3448 - previously it was not set to max(4*R, 2*s/X) as specified. Using the maximum of 1 second as upper bound (as it was done before) can have detrimental effects, especially if R is small. Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Consolidate handling of t_RTOGerrit Renker2006-12-021-15/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch * removes setting t_RTO in ccid3_hc_tx_init (per [RFC 3448, 4.2], t_RTO is undefined until feedback has been received); * makes some trivial changes (updates of comments); * performs a small optimisation by exploiting that the feedback timeout uses the value of t_ipi. The way it is done is safe, because the timeouts appear after the changes to t_ipi, ensuring that up-to-date values are used; * in ccid3_hc_tx_packet_recv, moves the t_rto statement closer to the calculation of the next_tmout. This makes the code clearer to read and is also safe, since t_rto is not updated until the next call of ccid3_hc_tx_packet_recv, and is not read by the functions called via ccid_wait_for_ccid(); * removes a `max' statement in sk_reset_timer, this is not needed since the timeout value is always greater than 1E6 microseconds. * adds `XXX'es to highlight that currently the nofeedback timer is set in a non-standard way Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Consistently update t_nom, t_ipi, t_deltaGerrit Renker2006-12-021-21/+17
| | | | | | | | | | | | | | | | | | | | | | This patch: * consolidates updating of parameters (t_nom, t_ipi, t_delta) which need to be updated at the same time, since they are inter-dependent * removes two inline functions which are no longer needed as a result of the above consolidation * resolves a FIXME regarding the re-calculation of t_ipi within the nofeedback timer, in the state where no feedback has previously been received * ties updating these parameters to updating the sending rate X, exploiting that all three parameters in turn depend on X; and using a small optimisation which can reduce the number of required instructions: only update the three parameters when X really changes Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Consolidate timer resetsGerrit Renker2006-12-022-10/+10
| | | | | | | | | | | | | | | | | | | | | | | This patch concerns updating the value of the nofeedback timer when no feedback has been received so far. Since in this case the value of R is still undefined according to [RFC 3448, 4.2], we can not perform step (3) of [RFC 3448, 4.3]. A clarification is provided in [RFC 4342, sec. 5], which states that in these cases the nofeedback timer (still) expires "after two seconds". Many thanks to Ian McDonald for pointing this out and providing the clarification. The patch * implements [RFC 4342, sec. 5] with regard to the above case * consolidates handling timer restart by - adding an appropriate jump label and - initialising the timeout value Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Resolve small FIXMEGerrit Renker2006-12-021-5/+4
| | | | | | | | | | | | This considers the case - ACK received while no packet has been sent so far. Resolved by printing a (rate-limited) warning message. Further removes an unnecessary BUG_ON in ccid3_hc_tx_packet_recv, received feedback on a terminating connection is simply ignored. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Remove redundant statements in ccid3_hc_tx_packet_sentGerrit Renker2006-12-021-21/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes a switch statement which is redundant since, * nothing is done in states TFRC_SSTATE_NO_SENT/TFRC_SSTATE_NO_FBACK * it is impossible that the function is called in the state TFRC_SSTATE_TERM, since --the function is called, in dccp_write_xmit, after ccid3_hc_tx_send_packet --if ccid3_hc_tx_send_packet is called in state TFRC_SSTATE_TERM, it returns -EINVAL, which means that ccid3_hc_tx_packet_sent will not be called (compare dccp_write_xmit) --> therefore, this case is logically impossible * the remaining state is TFRC_SSTATE_FBACK which conditionally updates t_ipi, t_nom, and t_delta. This is a no-op, since --t_ipi only changes when feedback is received --however, when feedback arrives via ccid3_hc_tx_packet_recv, there is an identical code block which performs the same set of operations --performing the same set of operations again in ccid3_hc_tx_packet_sent therefore does not change anything, since between the time of receiving the last feedback (and therefore update of t_ipi, t_nom, and t_delta), the value of t_ipi has not changed --since t_ipi has not changed, the values of t_delta and t_nom also do not change, they depend fully on t_ipi Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Avoid congestion control on zero-sized data packetsGerrit Renker2006-12-021-9/+5
| | | | | | | | | | | | | | | | | | | | This resolves an `XXX' in ccid3_hc_tx_send_packet(). The function is only called on Data and DataAck packets and returns a negative result on zero-sized messages. This is a reasonable policy since CCID 3 is a congestion-control module and congestion control on zero-sized Data(Ack) packets is in a way pathological. The patch uses a more suitable error code for this case, it returns the Posix.1 code `EBADMSG' ("Not a data message") instead of `ENOTCONN'. As a result of ignoring zero-sized packets, a the condition for a warning "First packet is data" in ccid3_hc_tx_packet_sent is always satisfied; this message has been removed since it will always be printed. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Simplify control flow of ccid3_hc_tx_send_packetGerrit Renker2006-12-021-22/+18
| | | | | | | | | This makes some logically equivalent simplifications, by replacing rc - values plus goto's with direct return statements. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] ccid3: Fix calculation of t_ipi time of scheduled transmissionGerrit Renker2006-12-021-5/+13
| | | | Problem:
* [DCCP] ccid3: Simplify control flow in the calculation of t_ipiGerrit Renker2006-12-021-7/+3
| | | | | | | | | | | This patch performs a simplifying (performance) optimisation: In each call of the inline function ccid3_calc_new_t_ipi(), the state is tested against TFRC_SSTATE_NO_FBACK. This is expensive when the function is called very often. A simpler solution, implemented by this patch, is to adapt the control flow. Background:
* [DCCP] ccid3: Fix bug in calculation of first t_nom and first t_ipiGerrit Renker2006-12-022-7/+6
| | | | Problem:
* [DCCP] ccid2: Allow window to grow largerAndrea Bittau2006-12-021-1/+1
| | | | | | | Now that we can stuff bigger ack vectors into options. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] CCID3: Remove non-referenced variableIan McDonald2006-12-021-3/+0
| | | | | | | This removes a non-referenced variable. Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [CCID 3]: Add annotations for socket structuresGerrit Renker2006-12-021-35/+55
| | | | | | | | This adds documentation to the CCID 3 rx/tx socket fields, plus some minor re-formatting. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: Simplified conditions due to use of enum:8 statesGerrit Renker2006-12-024-84/+63
| | | | | | | | | | | | | | | | | | | | | | This reaps the benefit of the earlier patch, which changed the type of CCID 3 states to use enums, in that many conditions are now simplified and the number of possible (unexpected) values is greatly reduced. In a few instances, this also allowed to simplify pre-conditions; where care has been taken to retain logical equivalence. [DCCP]: Introduce a consistent BUG/WARN message scheme This refines the existing set of DCCP messages so that * BUG(), BUG_ON(), WARN_ON() have meaningful DCCP-specific counterparts * DCCP_CRIT (for severe warnings) is not rate-limited * DCCP_WARN() is introduced as rate-limited wrapper Using these allows a faster and cleaner transition to their original counterparts once the code has matured into a full DCCP implementation. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: Add CCID3 debug support to KconfigGerrit Renker2006-12-022-8/+19
| | | | | | | | | | | | | | | This adds a CCID3 debug option to the configuration menu which is missing in Kconfig, but already used by the code. CCID 2 already provides such an entry. To enable debugging, set CONFIG_IP_DCCP_CCID3_DEBUG=y NOTE: The use of ccid3_{t,r}x_state_name is safe, since now only enum values can appear. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: enable debug messages also for static buildsGerrit Renker2006-12-022-12/+18
| | | | | | | | | | | This patch * makes debugging (when configured) work both for static / module build * provides generic debugging macros for use in other DCCP / CCID modules * adds missing information about debug parameters to Kconfig * performs some code tidy-up Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] CCID2: Code optimizationsAndrea Bittau2006-12-022-2/+21
| | | | | | | | | | | | These are code optimizations which are relevant when dealing with large windows. They are not coded the way I would like to, but they do the job for the short-term. This patch should be more neat. Commiter note: Changed the seqno comparisions to use {after,before}48 to handle wrapping. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: Introduce DCCP_{BUG{_ON},CRIT} macros, use enum:8 for the ccid3 statesGerrit Renker2006-12-022-35/+29
| | | | | | | | | | | This patch tackles the following problem: * the ccid3_hc_{t,r}x_sock define ccid3hc{t,r}x_state as `u8', but in reality there can only be a few, pre-defined enum names * this necessitates addiditional checking for unexpected values which would otherwise be caught by the compiler Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP]: fix printk format warningsRandy Dunlap2006-10-301-8/+10
| | | | | | | | | | | | | | Fix printk format warnings: build2.out:net/dccp/ccids/ccid2.c:355: warning: long long unsigned int format, u64 arg (arg 3) build2.out:net/dccp/ccids/ccid2.c:360: warning: long long unsigned int format, u64 arg (arg 3) build2.out:net/dccp/ccids/ccid2.c:482: warning: long long unsigned int format, u64 arg (arg 5) build2.out:net/dccp/ccids/ccid2.c:639: warning: long long unsigned int format, u64 arg (arg 3) build2.out:net/dccp/ccids/ccid2.c:639: warning: long long unsigned int format, u64 arg (arg 4) build2.out:net/dccp/ccids/ccid2.c:674: warning: long long unsigned int format, u64 arg (arg 3) build2.out:net/dccp/ccids/ccid2.c:720: warning: long long unsigned int format, u64 arg (arg 3) Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP]: Update documentation references.Gerrit Renker2006-10-243-12/+10
| | | | | | | | | | | | | | | | | | Updates the references to spec documents throughout the code, taking into account that * the DCCP, CCID 2, and CCID 3 drafts all became RFCs in March this year * RFC 1063 was obsoleted by RFC 1191 * draft-ietf-tcpimpl-pmtud-0x.txt was published as an Informational RFC, RFC 2923 on 2000-09-22. All references verified. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP]: Use constants for CCIDsIan McDonald2006-09-242-2/+2
| | | | | | | With constants for CCID numbers this now uses them in some places. Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
* [DCCP] CCID2: Add helper functions for changing important CCID2 stateAndrea Bittau2006-09-221-8/+23
| | | | | | | | | | | | Introduce methods which manipulate interesting congestion control state such as pipe and rtt estimate. This is useful for people wishing to monitor the variables of CCID and instrument the code [perhaps using Kprobes]. Personally, I am a fan of encapsulation---that justifies this change =D. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP] CCID2: Halve cwnd once upon multiple losses in a single RTTAndrea Bittau2006-09-222-18/+32
| | | | | | | | | | | | When multiple losses occur in one RTT, the window should be halved only once [a single "congestion event"]. This is now implemented, although not perfectly. Slightly changed the interface for changing the cwnd: pass hctx instead of dp. This is required in order to allow for change_cwnd to be called from _init(). Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP] CCID2: Allocate seq records on demandAndrea Bittau2006-09-222-32/+70
| | | | | | | | | | | | | | | Allocate more sequence state on demand. Each time a packet is sent out by CCID2, a record of it needs to be kept. This list of records grows proportionally to cwnd. Previously, the length of this list was hardcored and therefore the cwnd could only grow to this value (of 128). Now, records are allocated on demand as necessary---cwnd may grow as it wishes. The exceptional case of when memory is not available is not handled gracefully. Perhaps, cwnd should be capped at that point. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP] CCID2: Add Kconfig option for CCID2 debugAndrea Bittau2006-09-222-4/+11
| | | | | | | | | Allow the user to choose whether or not to enable CCID2 debugging via Kconfig. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP] CCID2: Tell DCCP to quickly check whether cwnd is availableAndrea Bittau2006-09-221-1/+1
| | | | | | | | | | | | | | If not enough cwnd is available, tell the sender to check again as soon as possible. This will increase CPU utilization (polling frequently for cwnd) but will improve network performance. That is, the sender will need to wait less before detecting the increase of cwnd. A better architecture would be for the CCID to call-back (or dequeue) from DCCP when it is able to transmit traffic -- not the other way around as it currently occurs. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP] CCID2: Initialize ssthresh to infinityAndrea Bittau2006-09-222-3/+6
| | | | | | | | | | Initialize the slow-start threshold to infinity. This way, upon connection initiation, slow-start will be exited only upon a packet loss. This patch will allow connections to quickly gain speed. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP] CCID2: Fix jiffie wrap issuesAndrea Bittau2006-09-221-4/+4
| | | | | | | | | Jiffies are now handled correctly (I hope) in CCID2. If they wrap, no problem. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP] ackvec: Fix how DCCP_ACKVEC_STATE_NOT_RECEIVED is usedAndrea Bittau2006-09-221-2/+2
| | | | | | | | | | Fix the way state is masked out. DCCP_ACKVEC_STATE_NOT_RECEIVED is defined as appears in the packet, therefore bit shifting is not required. This fix allows CCID2 to correctly detect losses. Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP]: Tidyup CCID3 list handlingIan McDonald2006-09-221-6/+6
| | | | | | | | | | | | As Arnaldo Carvalho de Melo points out I should be using list_entry in case the structure changes in future. Current code functions but is reliant on position and requires type cast. Noticed when doing this that I have one more variable than I needed so removing that also. Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP]: Fix CCID3Ian McDonald2006-08-266-193/+154
| | | | | | | | | | | | | | | | | | | | | | | | | This fixes CCID3 to give much closer performance to RFC4342. CCID3 is meant to alter sending rate based on RTT and loss. The performance was verified against: http://wand.net.nz/~perry/max_download.php For example I tested with netem and had the following parameters: Delayed Acks 1, MSS 256 bytes, RTT 105 ms, packet loss 5%. This gives a theoretical speed of 71.9 Kbits/s. I measured across three runs with this patch set and got 70.1 Kbits/s. Without this patchset the average was 232 Kbits/s which means Linux can't be used for CCID3 research properly. I also tested with netem turned off so box just acting as router with 1.2 msec RTT. The performance with this is the same with or without the patch at around 30 Mbit/s. Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP]: Introduce dccp_rx_hist_find_entryIan McDonald2006-08-262-0/+21
| | | | | | | This adds a new function dccp_rx_hist_find_entry. Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP]: Update contact details and copyrightIan McDonald2006-08-268-13/+13
| | | | | | | Just updating copyright and contacts Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
* [DCCP]: Fix typoIan McDonald2006-08-261-1/+1
| | | | | | | This fixes a small typo in net/dccp/libs/packet_history.c Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
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