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path: root/net/ipv4/tcp_highspeed.c
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2006-09-22[TCP] Congestion control (modulo lp, bic): use BUILD_BUG_ONAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-12[TCP] tcp_highspeed: Fix AI updates.Xiaoliang (David) Wei
I think there is still a problem with the AIMD parameter update in HighSpeed TCP code. Line 125~138 of the code (net/ipv4/tcp_highspeed.c): /* Update AIMD parameters */ if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) { while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd && ca->ai < HSTCP_AIMD_MAX - 1) ca->ai++; } else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) { while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd && ca->ai > 0) ca->ai--; In fact, the second part (decreasing ca->ai) never decreases since the while loop's inequality is in the reverse direction. This leads to unfairness with multiple flows (once a flow happens to enjoy a higher ca->ai, it keeps enjoying that even its cwnd decreases) Here is a tentative fix (I also added a comment, trying to keep the change clear): Acked-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-17[TCP]: Limited slow start for Highspeed TCPStephen Hemminger
Implementation of RFC3742 limited slow start. Added as part of the TCP highspeed congestion control module. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-02[TCP] tcp_highspeed: Fix problem observed by Xiaoliang (David) WeiStephen Hemminger
When snd_cwnd is smaller than 38 and the connection is in congestion avoidance phase (snd_cwnd > snd_ssthresh), the snd_cwnd seems to stop growing. The additive increase was confused because C array's are 0 based. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-05[TCP]: Fix snd_cwnd adjustments in tcp_highspeed.cJohn Heffner
Xiaoliang (David) Wei wrote: > Hi gurus, > > I am reading the code of tcp_highspeed.c in the kernel and have a > question on the hstcp_cong_avoid function, specifically the following > AI part (line 136~143 in net/ipv4/tcp_highspeed.c ): > > /* Do additive increase */ > if (tp->snd_cwnd < tp->snd_cwnd_clamp) { > tp->snd_cwnd_cnt += ca->ai; > if (tp->snd_cwnd_cnt >= tp->snd_cwnd) { > tp->snd_cwnd++; > tp->snd_cwnd_cnt -= tp->snd_cwnd; > } > } > > In this part, when (tp->snd_cwnd_cnt == tp->snd_cwnd), > snd_cwnd_cnt will be -1... snd_cwnd_cnt is defined as u16, will this > small chance of getting -1 becomes a problem? > Shall we change it by reversing the order of the cwnd++ and cwnd_cnt -= > cwnd? Absolutely correct. Thanks. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-12[TCP]: tcp_highspeed: fix AIMD table out-of-bounds accessPatrick McHardy
Covertiy #547 Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-17[TCP]: TCP highspeed build errorStephen Hemminger
There is a compile error that crept in with the last patch of TCP patches. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[TCP]: add tcp_slow_start helperStephen Hemminger
Move all the code that does linear TCP slowstart to one inline function to ease later patch to add ABC support. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[TCP]: fix congestion window update when using TSO deferalStephen Hemminger
TCP peformance with TSO over networks with delay is awful. On a 100Mbit link with 150ms delay, we get 4Mbits/sec with TSO and 50Mbits/sec without TSO. The problem is with TSO, we intentionally do not keep the maximum number of packets in flight to fill the window, we hold out to until we can send a MSS chunk. But, we also don't update the congestion window unless we have filled, as per RFC2861. This patch replaces the check for the congestion window being full with something smarter that accounts for TSO. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[ICSK]: Move TCP congestion avoidance members to icskArnaldo Carvalho de Melo
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>
2005-06-23[TCP]: Add High Speed TCP congestion control module.John Heffner
Sally Floyd's high speed TCP congestion control. This is useful for comparison and research. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>